High manganese steel pipeline with step-increasing weld zone erosion-corrosion resistance and manufacturing method of high manganese steel pipeline

Abstract

Improved steel welds, articles for making the same, and methods of making the same are provided. The present disclosure provides advantageous erosion, corrosion and / or crack resistant weld metals. More particularly, the present disclosure provides high manganese (Mn) weld metal compositions having enhanced resistance to erosion, corrosion and / or cracking, articles for making high manganese weld metal compositions having enhanced resistance to erosion, corrosion and / or cracking, and methods of making high manganese weld metal compositions having enhanced resistance to erosion, corrosion and / or cracking.

Description

[0001] This application is a divisional application of international application PCT / US2017 / 030691, filed on May 2, 2017, entitled "High-manganese steel pipe with stepped weld zone corrosion-resistant properties and manufacturing method thereof". International application PCT / US2017 / 030691 entered the Chinese national phase on November 1, 2018, with national application number 201780027234.7.

[0002] Cross-reference to related applications

[0003] This application claims the benefit and priority of U.S. Provisional Application No. 62 / 330,400, filed May 2, 2016, the entire disclosure of which is incorporated herein by reference. Technical Field

[0004] This disclosure relates to improved steel compositions and methods for manufacturing the same, and more particularly to high-manganese (Mn) steel welded pipes with enhanced erosion-corrosion resistance, mechanical strength, and toughness in the weld zone, and methods for manufacturing the same. Specifically, the high-manganese steel weld zone and heat-affected zone containing weld metal exhibit step-out erosion resistance, corrosion resistance, hydrogen embrittlement resistance, and stress corrosion cracking resistance in oil sand slurry environments. Background Technology

[0005] The following description describes this disclosure in relation to high-manganese steel slurry pipes for oil sands production. However, this disclosure is clearly applicable more broadly to any welding of corrosion-resistant / wear-resistant high-manganese steel components, wherein weldments with sufficient strength, toughness, and corrosion / wear resistance are desirable, including but not limited to any non-pipeline weldments. Various terms are defined in the following description. For convenience, a glossary of terms is provided before the claims.

[0006] Piping systems in mining operations (including the oil sands industry) are used to transport mixtures of solid rock and sand in liquid or slurry to processing plants and to recycle cuttings back to the mine or storage area. Existing slurry hydraulic transport pipelines are typically made of carbon steel (e.g., API 5L 45th Edition X65 or X70 grade steel). These pipelines are subjected to severe erosion-corrosion damage during use, with the lowest section / point (6 o'clock position) experiencing the most severe erosion-corrosion wear. To extend pipeline life, many operators rotate the pipeline periodically (e.g., every 3000 hours of use) by 90°. After three rotations or 12,000 hours of use, the pipeline is replaced. Oil sands operators have evaluated and used a variety of materials selected from martensitic stainless steels (e.g., Duracorr), hard cladding materials (e.g., WC-based, Cr3C2-based), and polymer lining materials (e.g., polyurethane). However, most engineering materials considered to date are only used for niche applications—due to relatively poor abrasion / erosion properties (e.g., polymer linings) or high material and / or manufacturing costs (e.g., WC-based hard metals, chromium carbide-based hard metal claddings) or limited corrosion-resistant layer thickness (e.g., bimetallic multilayer hardened steel materials).

[0007] Reinforced wear-resistant steel is also needed in the oil sands mining industry. Such oil sands deposits have been commercially exploited since the 1960s, and recovery rates have increased in recent years. Bituminous extraction is typically carried out using surface mining techniques in the case of shallow deposits (e.g., less than 100 m deep) or in-situ thermal extraction (e.g., involving the injection of steam, chemical solvents, and / or mixtures thereof) in the case of deep deposits located at greater depths (e.g., approximately 100 m or more). For surface mining of shallow oil sands, many types of heavy equipment and pipelines are used. First, the oil sands are typically excavated using bulldozers, which transfer the extracted material to transport trucks / vehicles. The vehicles transport the oil sands ore to an ore preparation facility, where the extracted ore is typically crushed and mixed with hot water. The oil sands slurry is then typically pumped via hydraulic transport pipelines to a primary separation unit (PSC), where bituminous oil is typically separated from the sand and water. After the asphalt is separated, the remaining sand and water slurry are then transported to the tailings pond via tailings pipelines to allow the sand to settle.

[0008] For example, the Canadian oil sands resources in northeastern Alberta contain large oil sands deposits covered by shallow overburden, making surface mining a highly efficient method for oil bitumen extraction. Generally, sand and gravel are quarried using bulldozers and transported to processing plants via hydraulic pipelines, with granular oil sands typically transported as a cement-containing slurry. After bitumen extraction, tailings are then typically transported from the processing facility to a site where solids and water separation occurs via pipeline. The hydraulic transport of large quantities of slurry mixtures results in significant metal loss in conventional metal pipelines, leading to short replacement cycles and substantial operating costs.

[0009] Therefore, oil sands mining and ore preparation processes involve several stress and / or impact abrasion challenges in multiple equipment / operation areas (e.g., shovels, hoppers, crushers, conveyors, vibrating screens, mud pumps, pipelines, etc.). For example, in downstream mud transport and extraction processes, challenges encountered in equipment, pipelines (e.g., hydro-transport pipelines and tailings pipelines), pumps, and / or PSCs include equipment / material erosion, corrosion, stress, wear, and / or abrasion. These equipment / material erosion / corrosion challenges result in significant repair, replacement, and / or maintenance costs, as well as production losses.

[0010] As mentioned, existing pipeline structures for hydraulic transport of slurry and tailings pipelines are typically constructed from low-carbon pipeline-grade steel (e.g., API Specification 5L, 45th Edition, X65, X70). Generally, rapidly moving solids in the slurry flow cause significant metal loss from the pipeline (e.g., metal loss from the inner wall of the pipe). Water-bearing and aerated slurry flows also typically accelerate pipeline erosion by creating a corrosive environment. Furthermore, particulate matter in the slurry (under the influence of gravity) causes damage, particularly along the lower interior of the pipeline. For example, hydraulic transport and tailings pipelines carrying sand and water slurry in oil sands operations undergo severe erosion-corrosion damage during use, with the bottom / points of the pipeline (e.g., at the 6 o'clock position) typically experiencing the most severe erosion and wear.

[0011] To extend pipeline lifespan, as discussed above, some mine operators have adopted the practice of periodically rotating pipelines. As also discussed above, oil sands operators have evaluated and used a variety of materials. However, these materials are used only for niche applications—often due to relatively poor abrasion / erosion performance (e.g., polymer linings), high material / manufacturing costs (e.g., WC-based hard metals, chromium carbide-based hard metal claddings), or limited available thicknesses (e.g., bimetallic multilayer hardened steel materials). Nevertheless, pipeline erosion and other issues remain serious problems, and alternative pipeline structures and / or materials are sought to achieve more efficient / economical operations / solutions.

[0012] Improved steel compositions with enhanced erosion / wear / corrosion resistance have recently been developed to reduce operating costs in mining operations. Specifically, improved high-Mn steel (2013EM118-PA) with enhanced wear / erosion / corrosion resistance has been developed for oil sands applications, including mud pipes. For successful implementation, high-Mn steel mud pipe sections must be joined together in the field to fabricate high-Mn steel mud pipes. Welding techniques suitable for constructing high-Mn steel mud pipes for oil sands projects are required. Several different types of joining methods are used to construct mud pipes, including girthbutt welding, flanges, and mechanical coupling.

[0013] To date, the weld metal developed for high-Mn steel is insufficient for joining corrosion-resistant high-Mn steel slurry pipes. Conventional high-Mn steel consumables used for welding cast Hadfield steel (commonly used in railway components) do not provide sufficient weld metal strength for joining newly developed corrosion-resistant high-Mn steel slurry pipes. High-Mn steel welding consumables for hard-coating applications cannot consistently provide the required weld metal toughness level for circumferential welds in slurry pipes.

[0014] U.S. Patent Application Publication No. 2013 / 0174941 describes a high-Mn steel developed for cryogenic applications, such as liquefied natural gas (LNG) storage containers. Weld metals for cryogenic high-Mn steels have been developed, such as in JK Choi et al., “High Manganese Austenitic Steel for Cryogenic Applications”, Proceedings of the 22nd nd Those described at the International ISOPE Conference, Rhodes, Greece 2012. These low-temperature high-Mn steel weld metals, while providing sufficient toughness at extremely low temperatures down to -200°C, do not offer sufficient weld metal strength for corrosion-resistant high-Mn steel slurry pipe applications.

[0015] U.S. Patent Application Publication No. 2014 / 0261918 describes a high-manganese steel composition with enhanced erosion-corrosion resistance to reduce operating costs in oil sands extraction operations, including mud pipelines. For mud pipeline applications, high-manganese steel sheets must be manufactured and welded into pipes. Such high-manganese steel pipes (weld metal and base steel) are exposed to a highly corrosive internal mud environment. Therefore, enhanced step-out erosion-corrosion resistance of the weld is required to fully utilize the benefits of high-manganese steel-based pipes.

[0016] Therefore, there is a need for improved weld zones and heat-affected zones in high-manganese steel that exhibit step-out resistance to erosion, corrosion, hydrogen embrittlement, and stress corrosion cracking, which can be used in the production of high-manganese steel pipes without undue concern for weldability or ease of use. These and other inefficiencies and opportunities for improvement are addressed and / or overcome by the compositions, articles, and methods disclosed herein. Summary of the Invention

[0017] Overview

[0018] This disclosure provides novel weld metals and methods for their manufacture and use, achieving sufficient strength, toughness, and high corrosion resistance for the fabrication of corrosion-resistant high-manganese steel slurry pipes via seam welding. Embodiments of this disclosure include weld metal chemistry, welding methods, and control over welding practices to produce weld microstructure and mechanical properties suitable for this application, thereby providing excellent strength of the joint and thus the entire welded structure.

[0019] In one aspect, the weld metal provided in this disclosure comprises: about 0.3 wt% to about 1.2 wt% carbon; about 0.1 wt% to about 3.0 wt% silicon; about 9.0 wt% to about 30 wt% manganese; at least one of the following: (i) less than or equal to about 0.3 wt% sulfur, (ii) less than or equal to about 0.03 wt% phosphorus, or (iii) combinations thereof; and the balance being iron. The weld metal may further comprise less than or equal to about 8 wt% chromium; less than or equal to about 6 wt% nickel; less than or equal to about 6 wt% molybdenum; less than or equal to about 5 wt% tungsten; less than or equal to about 4 wt% copper; less than or equal to about 2 wt% niobium; less than or equal to about 2 wt% vanadium; less than or equal to about 2 wt% titanium; less than or equal to about 0.4 wt% nitrogen; and less than or equal to about 1 wt% boron.

[0020] Another aspect of this disclosure provides a novel metal-cored welding wire for submerged arc welding. The welding wire comprises a steel sheath and a core containing powder of alloying elements as described above regarding the composition of the weld metal.

[0021] Another aspect of this disclosure relates to a method for welding high-manganese steel. The method of applying weld metal uses submerged arc welding. The weld metal chemistry and welding parameters (e.g., heat input) are controlled to ensure reduced susceptibility to solidification cracking and to prevent significant degradation of the toughness and strength of the weld metal and the heat-affected zone (HAZ). In one embodiment, the method comprises: supplying at least one high-manganese steel piece; supplying a metal-cored welding wire; immersing said at least one high-manganese steel piece in slag and an arc stabilizer; and applying an electric current to said metal-cored welding wire to create a liquid alloy steel composition on said at least one high-manganese steel piece. The metal-cored welding wire may comprise: about 0.3 wt% to about 1.2 wt% carbon; about 0.1 wt% to about 3.0 wt% silicon; about 9.0 wt% to about 30 wt% manganese; at least one of the following: (i) less than or equal to about 0.3 wt% sulfur, (ii) less than or equal to about 0.03 wt% phosphorus, or (iii) a combination thereof; and the balance being iron.

[0022] In particular, this disclosure relates to the following implementation schemes: 1. A welding composition comprising: 0.3% to 1.2% by weight of carbon; 0.1% to 3.0% by weight of silicon; 9.0% to 30% manganese by weight; Chromium in an amount of 8% by weight or less; Nickel in amounts less than or equal to 6% by weight; Molybdenum in amounts less than or equal to 6% by weight; Tungsten in amounts less than or equal to 5% by weight; Copper in amounts less than or equal to 4% by weight; Niobium in amounts less than or equal to 2% by weight; Vanadium in amounts less than or equal to 2% by weight; Amount of titanium less than or equal to 2% by weight; Nitrogen in amounts less than or equal to 0.4% by weight; Boron in an amount less than or equal to 1% by weight; At least one of the following: i. Sulfur in an amount less than or equal to 0.3% by weight; ii. Phosphorus in an amount less than or equal to 0.03% by weight; or iii. Their combination; and The remainder is iron.

[0023] 2. The composition of embodiment 1, wherein at least one of the following is true: Chromium content is 2 to 6% by weight. Nickel content is 0 to 5% by weight. Molybdenum content is 0.5% to 3% by weight. Tungsten is 0.1 to 2% by weight. Copper is present in amounts less than 2% by weight; Niobium is present in amounts less than 1% by weight; Vanadium is present in amounts less than 1% by weight; Titanium is present in amounts less than 1% by weight; Nitrogen content is 0.01 to 0.3% by weight. Boron is 0.01 to 0.4% by weight; or Its combination.

[0024] 3. The welding composition of embodiment 1 or 2, wherein at least one of the following is present: carbon at 0.45 to 0.7 wt%; silicon at 0.2 to 1.5 wt%; manganese at 12 to 20 wt%; or a combination thereof.

[0025] 4. A metal-cored welding wire for submerged arc welding, the welding wire comprising a steel sheath and a powder-containing core, wherein the powder is: 0.3% to 1.2% by weight of carbon; 0.1% to 3.0% by weight of silicon; 9.0% to 30% manganese by weight; Less than 8% by weight of chromium; Less than 6% by weight of nickel; Molybdenum in amounts less than 6% by weight; Less than 5% by weight of tungsten; Copper in amounts less than 4% by weight; Less than 2% by weight of niobium; Vanadium in amounts less than 2% by weight; Less than 2% by weight of titanium; Nitrogen in amounts less than 0.4% by weight; Boron in amounts less than 1% by weight; At least one of the following: i. Sulfur content less than 0.3% by weight; ii. Phosphorus less than 0.03% by weight; or iii. Their combination; and The remainder is iron.

[0026] 5. The metal-cored welding wire of embodiment 4, wherein the steel is carbon steel or high-manganese steel.

[0027] 6. The metal-core welding wire of embodiment 4 or 5, wherein the steel sheath has a welded longitudinal seam.

[0028] 7. The metal-core welding wire according to any one of embodiments 4-6, wherein the surface of the steel sheath is coated with copper.

[0029] 8. A method for welding high-manganese steel, the method comprising: supplying at least one high-manganese steel part; supplying a metal-cored welding wire according to any one of embodiments 4-7; immersing the at least one high-manganese steel part in slag and an arc stabilizer; and applying an electric current to the metal-cored welding wire to create a liquid alloy steel composition on the at least one high-manganese steel part.

[0030] 9. The method of embodiment 8, wherein the slag comprises at least one of the following: 22-24% Al2O3; 10-12% SiO2; 6-8% MnO; 22.5-24.5% CAF2; 10.5-12.5% ​​MgO; 11.5-13.5% CO2; 2.5-4.5% CaO; 0.5-2.5% Na2O; 1.0-3.0% TiO2; 0.5-1.6% ZrO2; 0.3-1.3% K2O; 0.2-1.2% Fe; 0.2-2.2% Mn; 0.1-1.0% Si; or combinations thereof.

[0031] 10. The method of embodiment 8 or 9, wherein the at least one high-manganese steel member is at least two high-manganese steel members, and an electric current is applied to the metal core welding wire to generate a liquid steel composition at the joint between the at least two high-manganese steel members.

[0032] 11. The method of any one of embodiments 8-10, further comprising cooling the liquid alloy steel composition to form an alloy steel composition for joining the at least two high-manganese steel parts.

[0033] 12. The method according to any one of embodiments 8-11, wherein the slag and arc stabilizer comprise at least one of TiO2, SiO2, ZrO2, Al2O3, Na2O, K2O, metal fluoride, or combinations thereof.

[0034] 13. The method according to any one of embodiments 8-12, wherein the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

[0035] 14. The method of any one of embodiments 8-13, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

[0036] 15. The method according to any one of embodiments 8-14, wherein the slag comprises at least one of the following: 23.1% Al2O3; 11.2% SiO2; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

[0037] Consider any combination or arrangement of the implementation schemes. Other advantageous steps, features, functions, and applications of the systems and methods disclosed herein will be apparent from the following description, particularly when read in conjunction with the accompanying drawings. All references listed in this disclosure are hereby incorporated in their entirety. Brief description of the attached diagram

[0038] Exemplary embodiments of this disclosure are further described with reference to the accompanying drawings. It should be noted that the various steps, features, and combinations of steps / features illustrated in the following description and the drawings may be arranged and organized differently to produce embodiments still within the spirit and scope of this disclosure. To assist those skilled in the art in making and utilizing the disclosed systems, assemblies, and methods, reference is made to the accompanying drawings, in which: Figure 1 Oil sands surface extraction process flow; Figure 2 Graphical illustration of the predictive effect of alloying elements on stacking fault energy; Figure 3 These are the stress-strain curves of two high-Mn steel seam welds with different carbon contents; Figure 4 Abrasive wear resistance of weld metal as determined by ASTM G65 rotating rubber wheel test; and Figure 5 This illustrates an example of preferential weld corrosion in high-Mn steel welds under simulated mud pipe conditions.

[0039] Detailed Explanation

[0040] The exemplary embodiments disclosed herein exemplify advantageous steel compositions and systems, and methods / techniques thereof. However, it should be understood that the disclosed embodiments are merely illustrative and may be embodied in various forms. Therefore, the details disclosed herein regarding exemplary steel compositions / manufacturing methods and related assembly and use methods / techniques should not be construed as limiting, but rather serve only as a basis for teaching those skilled in the art how to manufacture and utilize the advantageous steel compositions of this disclosure. The drawings are not necessarily to scale and in some views, parts may be enlarged for clarity.

[0041] Compositions, articles, and methods relating to a surprising and unexpected discovery are now described, in which the compositions described herein provide high-manganese welded pipes with excellent erosion-corrosion resistance, mechanical strength, and toughness in the weld zone. In particular, the weld zone and heat-affected zone containing the weld metal exhibit step-out erosion resistance, corrosion resistance, hydrogen embrittlement resistance, and stress corrosion cracking resistance in environments such as oil sands.

[0042] According to one aspect of this disclosure, a weld metal is provided. Unless otherwise expressly specified, all percentages of the composition of the weld metal herein are expressed in weight percent (%). The weld metal comprises: about 0.3 wt% to about 1.2 wt% carbon; about 0.1 wt% to about 3.0 wt% silicon; about 9.0 wt% to about 30 wt% manganese; at least one or both of ≤ about 0.3 wt% sulfur and ≤ about 0.03 wt% phosphorus; and the balance is iron. The weld metal of this disclosure may be referred to as corrosion-resistant high-manganese steel or ER-HMS. Although the balance of the weld metal composition is iron, the weld metal may include other unlisted components, such as impurities.

[0043] The weld metal may further contain ≤ about 8 wt% chromium, ≤ about 6 wt% nickel, ≤ about 6 wt% molybdenum, ≤ about 5 wt% tungsten, ≤ about 4 wt% copper, ≤ about 2 wt% niobium, ≤ about 2 wt% vanadium, ≤ about 2 wt% titanium, ≤ about 0.4 wt% nitrogen and ≤ about 1 wt% boron.

[0044] All numerical values ​​in the detailed descriptions and claims herein are modified by “approximately” or “roughly” and take into account experimental errors and variations expected by one of ordinary skill in the art.

[0045] When providing numerical ranges, it is to be understood that, unless the context clearly specifies otherwise, all intermediate values ​​between the upper and lower limits of the range (to 1 / 10 of the lower limit) and any other specified or intermediate values ​​within the specified range are included in this disclosure. Consider a range from any lower limit to any upper limit. The upper and lower limits of these smaller ranges that may be independently included within the smaller range are also included in this disclosure, subject to any expressly excluded limits within the specified range. If a specified range contains one or both limits, the range that does not include any or both of these included limits is also included in this disclosure.

[0046] Although similar or equivalent methods and materials to those described herein may be used in the practice or testing of this disclosure, preferred methods and materials are now described. All publications mentioned herein are hereby cited and incorporated to disclose and describe the methods and / or materials associated with those publications.

[0047] It must be noted that, unless the context clearly specifies otherwise, the singular forms introduced by articles as used herein and in the appended claims include plural objects.

[0048] The term “and / or” as used in this specification and claims should be understood to mean “any one or both” of the elements so connected, that is, elements that exist jointly in some cases and disjunctly in others. Multiple elements listed with “and / or” should be interpreted in the same way, that is, “one or more” elements are connected thereby. Other elements may optionally exist in addition to those specifically indicated by the “and / or” item, whether related to or unrelated to those specifically indicated. Thus, as a non-limiting example, when used with open-ended terms such as “comprising,” reference to “A and / or B” may, in one embodiment, mean only A (optionally including elements other than B); in another embodiment, mean only B (optionally including elements other than A); in yet another embodiment, mean A and B (optionally including other elements), and so on.

[0049] The word “or” as used in this specification and claims shall be understood to have the same meaning as “and / or” as defined above. For example, when separating items in a list, “or” or “and / or” shall be interpreted as inclusive, that is, including at least one of a plurality of or a series of elements, and including more than one, and optionally including other unlisted items. Only when the term expressly indicates the contrary, such as “only one” or “exact one” or used in the claims, “consisting of” means including exactly one of a plurality of or a series of elements. Generally, when preceded by an exclusive term, such as “any,” “one of,” “only one,” or “exact one,” the term “or” as used herein shall only be interpreted as indicating an exclusive alternative (i.e., “this or that but not both”).

[0050] In the claims and the foregoing description, all conjunctions such as “comprising,” “including,” “with,” “having,” “containing,” “involving,” “owning,” and “composed of” are understood to be open-ended, meaning including but not limited to. As stated in 10 United States Patent Office Manual of Patent Examining Procedures, Section 2111.03, only the conjunctions “composed of” and “substantially composed of” should be closed or semi-closed conjunctions, respectively.

[0051] Regarding the list of one or more elements, the term "at least one" as used in this specification and claims should be understood to mean at least one element selected from any one or more elements in the list, but not necessarily including each and every element specifically listed in the list, and does not exclude any combination of elements in the list. This definition also allows for the optional presence of elements other than those specifically specified in the list of elements to which the term "at least one" refers, whether related to or unrelated to those specifically specified elements. Thus, as a non-limiting example, "at least one of A and B" (or equivalently, "at least one of A or B", or equivalently, "at least one of A and / or B") may mean at least one in one embodiment, optionally including more than one A and not including B (optionally including elements other than B); in another embodiment, it means at least one, optionally including more than one B and not including A (optionally including elements other than A); in yet another embodiment, it means at least one, optionally including more than one A and at least one, optionally including more than one B (optionally including other elements); and so on.

[0052] It should also be understood that, unless expressly instructed otherwise, in any method claimed herein that includes more than one step or operation, the order of the steps or operations of the method is not necessarily limited to the order in which the steps or operations of the method are listed.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit this disclosure.

[0054] definition

[0055] CRA: Corrosion-resistant alloys can refer to, but are by no means limited to, materials specifically formulated for manufacturing equipment used in corrosive environments to possess good corrosion resistance. Corrosion-resistant alloys can be formulated for a wide variety of harsh and corrosive conditions.

[0056] Ductility: can refer to, but is by no means limited to, the measure of a material’s ability to undergo significant plastic deformation before fracture; it can be expressed as elongation (% EL) or reduction of area (% AR).

[0057] Corrosion resistance: This can refer to, but is by no means limited to, the inherent resistance of a material to degradation caused by exposure to reactive or corrosive environments.

[0058] Toughness: can refer to, but is by no means limited to, the tolerance to crack initiation and propagation.

[0059] Stress corrosion cracking (SCC): can refer to, but is by no means limited to, cracking of materials caused by the simultaneous action of stress and reactive and corrosive environments.

[0060] Sulfide stress cracking (SSC): can refer to, but is by no means limited to, cracking of materials caused by exposure to fluids containing hydrogen sulfide (e.g., H2S).

[0061] Yield strength: can refer to, but is not limited to, the ability of a material to withstand a load without deformation.

[0062] Cooling rate: can refer to, but is not limited to, the cooling rate of a material, which is usually measured at or near the center of a material.

[0063] Austenite: can refer to, but is by no means limited to, the metallographic structure of steel having a face-centered cubic (FCC) atomic crystal structure.

[0064] Martensite: can refer to, but is not limited to, the metallographic phase in steel formed by diffusionless phase transformation, wherein the parent phase (usually austenite) and the product phase have a specific orientation relationship.

[0065] ε-martensite: can refer to, but is by no means limited to, a specific form of martensite with a hexagonal close-packed atomic crystal structure that forms when the austenite phase is cooled or strained. ε-martensite typically forms on the close-packed (111) plane of the austenite phase and is morphologically similar to deformation twins or stacking faultclusters.

[0066] α' (alpha prime)-martensite: can refer to, but is by no means limited to, a specific form of martensite with a body-centered cubic (BCC) or body-centered tetragonal (BCT) atomic crystal structure formed when the austenitic phase is cooled or strained; α'-martensite usually forms as lamellar crystals.

[0067] Carbides: can refer to, but are by no means limited to, compounds of iron / metal and carbon.

[0068] Welded component: can refer to, but is not limited to, a unit formed by welding together assemblies of parts.

[0069] Weld metal: can refer to, but is by no means limited to, the welded portion or weld joint that has been fused together in its formation.

[0070] Heat-affected zone (HAZ): can refer to, but is not limited to, the portion of the base metal that did not melt during the welding process but whose microstructure and mechanical properties were altered by the welding heat.

[0071] Preferred weld corrosion (PWC): can refer to, but is by no means limited to, selective corrosion of the metal associated with the weld, resulting in corrosion of the weld metal and / or the adjacent heat-affected zone (HAZ) rather than the parent base metal.

[0072] Weld metallurgy / microstructure / mechanical properties

[0073] The novel corrosion-resistant high-Mn steel (ER-HMS) weldment disclosed herein provides the strength, toughness, and high corrosion resistance required for seam welding of corrosion-resistant HMS pipes. The microstructure required to meet these property requirements is achieved through appropriate control of the weld metal chemistry and welding process parameters.

[0074] Traditional high-manganese steel consumables (such as Hadfield steel welding wire commonly used in railway components) do not provide suitable weld metal strength or corrosion resistance in newly developed corrosion-resistant high-manganese steel slurry pipes. The high-manganese steel weld metal described in this disclosure provides excellent step-out erosion / corrosion resistance in slurry pipe applications.

[0075] The ER-HMS weld metal must achieve the minimum tensile strength properties required for this application (e.g., slurry piping). For example, the weld metal yield strength may be higher than the yield strength of the corrosion-resistant HMS base pipe or higher than the specified minimum yield strength (SMYS) required for slurry piping design. The weld metal ultimate tensile strength may also be higher than the specified minimum ultimate tensile strength (SMUTS) of the base pipebody. Additionally, the weld metal must provide a certain minimum specified elongation level. The ER-HMS weld metal achieves each of these requirements because it is designed to contain a highly metastable austenitic phase that transforms into a hard martensite phase and undergoes twinning upon strain. Furthermore, solid solution strengthening elements (e.g., molybdenum) in the weld metal provide additional strengthening by interfering with lattice dislocation movement. This combination of strengthening mechanisms provides the high strength and work hardening rate required for the tensile strength of seam welds in typical slurry piping applications. As an example, the properties of the tested ER-HMS weld metal are shown... Figure 4 The weld requirements are compared with those for seam welds in pipeline designs based on API X70 (SMYS 70 ksi). API X70 design is common in oil sand slurry pipeline designs. Modifications to the ER-HMS weld metal chemistry can be made within the scope disclosed herein to achieve the required weld metal tensile properties for a range of possible slurry pipeline classes, including X52, X60, X65, X70, and X80.

[0076] The high-manganese steel weld metal described in this disclosure is required to have similar mechanical and corrosive properties to the high-manganese steel base metal used for slurry piping applications, because the microstructure and stress distribution in these regions greatly affect the strength of the joint and therefore the entire welded structure. Therefore, in one embodiment, the ER-HMS weld metal of this disclosure has a similar microstructure and similar strain-induced transformation behavior to the high-manganese steel base metal used for, for example, slurry piping applications.

[0077] In one embodiment, the weld metal comprises: about 0.3 wt% to about 1.2 wt% carbon; about 0.1 wt% to about 3.0 wt% silicon; about 9.0 wt% to about 30 wt% manganese; at least one or both of ≤ about 0.3 wt% sulfur and ≤ about 0.03 wt% phosphorus; ≤ about 8 wt% chromium; ≤ about 6 wt% nickel; ≤ about 6 wt% molybdenum; ≤ about 5 wt% tungsten; ≤ about 4 wt% copper; ≤ about 2 wt% niobium; ≤ about 2 wt% vanadium; ≤ about 2 wt% titanium; ≤ about 0.4 wt% nitrogen; ≤ about 1 wt% boron, and the balance of the composition is iron. In a particular embodiment, carbon is about 0.45 to about 0.7 wt%, silicon is about 0.2 to about 1.5 wt%, and / or manganese is about 12 to about 20 wt%. In another embodiment, chromium is about 2 to about 6 wt%, nickel is ≤ about 5 wt%, molybdenum is about 0.5 to about 3 wt%, tungsten is about 0.1 to about 2 wt%, copper is ≤ about 2 wt%, niobium is ≤ about 1 wt%, vanadium is ≤ about 1 wt%, titanium is ≤ about 1 wt%, nitrogen is about 0.01 to about 0.3 wt%, and / or boron is about 0.01 to about 0.4 wt%.

[0078] The high-manganese steel weld metal and HAZ described in this disclosure are required to have similar mechanical and erosion / corrosion properties to the base metal high-manganese steel used in the bonding process (e.g., for slurry piping applications). Therefore, in one embodiment, the ER-HMS weld metal and HAZ of this disclosure have a similar microstructure and strain-induced transformation behavior to the base metal high-manganese steel. Unlike conventional carbon steel, the microstructure of high-manganese steel consists of a metastable austenitic phase with a face-centered cubic (fcc) structure at room temperature.

[0079] Under strain, the metastable austenitic phase can undergo a variety of different phase transformations via strain-induced transformation. These transformations include: depending on the specific steel chemistry and / or temperature, the austenitic phase transforms into a microtwinned (fcc) structure (where twins are aligned with the matrix), ε-martensite (hexagonal lattice), and α'-martensite (body-centered tetragonal lattice). These transformation products are crucial to the unique properties of high-manganese steel. For example, fine twins effectively divide the primary austenite grains and act as strong barriers to dislocation movement. This effectively refines the grains and results in an excellent combination of high ultimate tensile strength and ductility.

[0080] The chemistry of corrosion-resistant high-manganese steel has been specifically tailored to produce transformation products that provide excellent corrosion and wear resistance. The base metal is formulated to contain a highly metastable austenitic phase, which typically transforms into hard α'-martensite upon strain. After surface wear of these steels, the surface layer of the highly metastable austenitic phase can transform into α'-martensite. This friction-induced phase transformation results in the formation of a thin, hard surface layer of martensite within the tough, untransformed metastable austenite. This is a desirable combination for wear / corrosion applications.

[0081] To achieve the desired mechanical properties in ER-HMS weld metal, the microstructure should be similar to that of the erosion-resistant HMS base metal. In one embodiment, the manganese content is similar in both the weld metal and the base metal. Manganese is a major element in high-manganese steel and is important for stabilizing the austenitic structure during cooling and deformation. Furthermore, manganese deoxidizes like silicon and strengthens the weld metal through a solid solution strengthening mechanism. Additionally, manganese increases the work hardening index when within suitable ranges. For example, it has been determined that approximately 9 wt% or more of manganese is needed to stabilize the dominant austenitic phase within the weld metal. It has also been determined that more than approximately 30 wt% of manganese leads to a decrease in weld metal toughness within the weld metal. Therefore, manganese can be approximately 9 wt% to approximately 30 wt% of the total weld metal or the core of the metal-cored wire of this disclosure. In a particular embodiment, manganese is present at approximately 12 wt% to approximately 20 wt% of the total weld metal or the core of the metal-cored wire. In some embodiments, the core of the weld metal or metal-cored wire comprises approximately 9% to approximately 28% by weight, approximately 9% to approximately 26% by weight, approximately 9% to approximately 24% by weight, approximately 9% to approximately 22% by weight, approximately 9% to approximately 20% by weight, approximately 9% to approximately 18% by weight, approximately 9% to approximately 16% by weight, approximately 9% to approximately 14% by weight, approximately 9% to approximately 12% by weight, approximately 10% to approximately 30% by weight, approximately 10% to approximately 28% by weight, approximately 10% to approximately 26% by weight, approximately 10% to approximately 24% by weight, approximately 10% to approximately 22% by weight, approximately 10% to approximately 20% by weight, approximately 10% to approximately 18% by weight, approximately 10% to approximately 16% by weight, approximately 10% to approximately 14% by weight, approximately 10% to approximately 12% by weight, approximately 12% to approximately 30% by weight, approximately 12% to approximately 30% by weight. Approximately 28% by weight, approximately 12% to approximately 26% by weight, approximately 12% to approximately 24% by weight, approximately 12% to approximately 22% by weight, approximately 12% to approximately 20% by weight, approximately 12% to approximately 18% by weight, approximately 12% to approximately 16% by weight, approximately 12% to approximately 14% by weight, approximately 14% to approximately 30% by weight, approximately 14% to approximately 28% by weight, approximately 14% to approximately 26% by weight, approximately 14% to approximately 24% by weight, approximately 14% to approximately 22% by weight, approximately 14% to approximately 20% by weight, approximately 14% to approximately 18% by weight, approximately 14% to approximately 16% by weight, approximately 16% to approximately 30% by weight, approximately 1% to approximately 28% by weight, approximately 16% to approximately 26% by weight, approximately 16% to approximately 24% by weight, approximately 16% to approximately 22% by weight, approximately 16% to approximately 20% by weight.Approximately 16% to approximately 18% by weight, approximately 18% to approximately 30% by weight, approximately 18% to approximately 28% by weight, approximately 18% to approximately 26% by weight, approximately 18% to approximately 24% by weight, approximately 18% to approximately 22% by weight, approximately 18% to approximately 20% by weight, approximately 20% to approximately 30% by weight, approximately 20% to approximately 28% by weight, approximately 20% to approximately 26% by weight, approximately 20% to approximately 24% by weight, large Manganese, approximately 20% to approximately 22% by weight, approximately 22% to approximately 30% by weight, approximately 22% to approximately 28% by weight, approximately 22% to approximately 26% by weight, approximately 22% to approximately 24% by weight, approximately 24% to approximately 30% by weight, approximately 24% to approximately 28% by weight, approximately 24% to approximately 26% by weight, approximately 26% to approximately 30% by weight, approximately 26% to approximately 28% by weight, or approximately 28% to approximately 30% by weight. In a particular embodiment, the weld metal or the core of the metal-cored welding wire contains approximately 9% by weight, approximately 10% by weight, approximately 11% by weight, approximately 12% by weight, approximately 13% by weight, approximately 14% by weight, approximately 15% by weight, approximately 16% by weight, approximately 17% by weight, approximately 18% by weight, approximately 19% by weight, approximately 20% by weight, approximately 21% by weight, approximately 22% by weight, approximately 23% by weight, approximately 24% by weight, approximately 25% by weight, approximately 26% by weight, approximately 27% by weight, approximately 28% by weight, approximately 29% by weight, or approximately 30% by weight of manganese.

[0082] Carbon is an effective austenite stabilizer and has high solubility in the austenitic phase. Therefore, carbon alloying can be used to stabilize the austenitic phase during the cooling of molten alloys. When added in appropriate amounts, carbon also strengthens the matrix through solution hardening and affects arc stability and weld metal toughness. The weld material of this disclosure may comprise from approximately 0.3 wt% to approximately 1.2 wt% of the total weld metal or the core of the metal-cored wire. It has been determined that when the carbon content in the metal-cored wire is less than 0.3 wt%, the weld metal lacks sufficient strength and corrosion resistance, and when the carbon content exceeds 1.2 wt%, the toughness decreases and the weld metal / seam exhibits a higher susceptibility to hot cracking. In one particular embodiment, the carbon content is from approximately 0.45 wt% to approximately 0.7 wt%. In some embodiments, the weld metal or the core of the metal-cored welding wire contains about 0.3 wt% to about 1.0 wt%, about 0.3 wt% to about 0.8 wt%, about 0.3 wt% to about 0.6 wt%, about 0.4 wt% to about 1.2 wt%, about 0.4 wt% to about 1.0 wt%, about 0.4 wt% to about 0.8 wt%, about 0.4 wt% to about 0.6 wt%, about 0.6 wt% to about 1.2 wt%, about 0.6 wt% to about 1.0 wt%, about 0.6 wt% to about 0.8 wt%, about 0.8 wt% to about 1.2 wt%, or about 1.0 wt% to about 1.2 wt% carbon. In some embodiments, the weld metal or the core of the metal-cored wire contains about 0.3 wt%, about 0.4 wt%, about 0.5 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, about 1.0 wt%, about 1.1 wt%, or about 1.2 wt% carbon.

[0083] The addition of silicon provides solid solution strengthening in addition to maintaining the α'-martensite transformation, while also promoting the formation of ε-martensite during deformation at ambient temperature. Silicon also acts as a ferrite stabilizer and deoxidizer. Silicon can be present in the weld metal or the core of the metal-core welding wire at approximately 0.1 wt% to approximately 3 wt%. It has been determined that when the silicon content is less than 0.1 wt%, the weld metal does not have sufficient strength. Furthermore, the insufficient formation of SiO2 as a deoxidation product of the weld metal causes slag viscosity imbalance and impairs welding performance. In addition, when the silicon content is greater than 3 wt%, the toughness decreases. In one particular embodiment, the silicon content is approximately 0.2 wt% to approximately 1.5 wt%. In some embodiments, the weld metal or the core of the metal-cored welding wire contains approximately 0.1 wt% to approximately 2.8 wt%, approximately 0.1 wt% to approximately 2.6 wt%, approximately 0.1 wt% to approximately 2.4 wt%, approximately 0.1 wt% to approximately 2.2 wt%, approximately 0.1 wt% to approximately 2.0 wt%, approximately 0.1 wt% to approximately 1.8 wt%, approximately 0.1 wt% to approximately 1.6 wt%, approximately 0.1 wt% to approximately 1.4 wt%, approximately 0.1 wt% to approximately 1.2 wt%, and approximately 0.1 wt% to approximately [missing information - likely a percentage]. About 1.0 wt%, about 0.1 wt% to about 0.8 wt%, about 0.1 wt% to about 0.6 wt%, about 0.1 wt% to about 0.4 wt%, about 0.3 wt% to about 3.0 wt%, about 0.3 wt% to about 2.8 wt%, about 0.3 wt% to about 2.6 wt%, about 0.3 wt% to about 2.4 wt%, about 0.3 wt% to about 2.2 wt%, about 0.3 wt% to about 2.0 wt%, about 0.3 wt% to about 1.8 wt%, about 0.3 wt%. Up to about 1.6 wt%, about 0.3 wt% to about 1.4 wt%, about 0.3 wt% to about 1.2 wt%, about 0.3 wt% to about 1.0 wt%, about 0.3 wt% to about 0.8 wt%, about 0.3 wt% to about 0.6 wt%, about 0.5 wt% to about 3.0 wt%, about 0.5 wt% to about 2.8 wt%, about 0.5 wt% to about 2.6 wt%, about 0.5 wt% to about 2.4 wt%, about 0.5 wt% to about 2.2 wt%, about 0.5 wt%. From approximately 2.0 wt%, from approximately 0.5 wt% to approximately 1.8 wt%, from approximately 0.5 wt% to approximately 1.6 wt%, from approximately 0.5 wt% to approximately 1.4 wt%, from approximately 0.5 wt% to approximately 1.2 wt%, from approximately 0.5 wt% to approximately 1.0 wt%, from approximately 0.5 wt% to approximately 0.8 wt%, from approximately 0.7 wt% to approximately 3.0 wt%, from approximately 0.7 wt% to approximately 2.8 wt%, from approximately 0.7 wt% to approximately 2.6 wt%, from approximately 0.7 wt% to approximately 2.4 wt%, and approximately 0.7% by weight to about 2.2% by weight, about 0.7% by weight to about 2.0% by weight, about 0.7% by weight to about 1.8% by weight, about 0.7% by weight to about 1.6% by weight, about 0.7% by weight to about 1.4% by weight, about 0.7% by weight to about 1.2% by weight, about 0.7% by weight to about 1.0% by weight, about 0.9% by weight to about 3.0% by weight, about 0.9% by weight to about 2.8% by weight, about 0.9% by weight to about 2.6% by weight, about 0.9% by weight to about 2.4% by weight, about 0.9% by weight to about 2.2% by weight, about 0.9% by weight to about 2.0% by weight, about 0.9% by weight to about 1.8% by weight, large About 0.9 wt% to about 1.6 wt%, about 0.9 wt% to about 1.4 wt%, about 0.9 wt% to about 1.2 wt%, about 1.0 wt% to about 3.0 wt%, about 1.0 wt% to about 2.8 wt%, about 1.0 wt% to about 2.6 wt%, about 1.0 wt% to about 2.4 wt%, about 1.0 wt% to about 2.2 wt%, about 1.0 wt% to about 2.0 wt%, about 1.0 wt% to about 1.8 wt%, about 1.0 wt% to about 1.6 wt%, about 1.0 wt% to about 1.4 wt%, about 1.0 wt% to about 1.2 wt%, about 1.2 wt% to about 3.0 wt%. Approximately 1.2% to approximately 2.8% by weight, approximately 1.2% to approximately 2.6% by weight, approximately 1.2% to approximately 2.4% by weight, approximately 1.2% to approximately 2.2% by weight, approximately 1.2% to approximately 2.0% by weight, approximately 12% to approximately 1.8% by weight, approximately 1.2% to approximately 1.6% by weight, approximately 1.2% to approximately 1.4% by weight, approximately 1.4% to approximately 3.0% by weight, approximately 1.4% to approximately 2.8% by weight, approximately 1.4% to approximately 2.6% by weight, approximately 1.4% to approximately 2.4% by weight, approximately 1.4% to approximately 2.2% by weight, approximately 1.4% to approximately 2.0% by weight. %, approximately 1.4 wt% to approximately 1.8 wt%, approximately 1.4 wt% to approximately 1.6 wt%, approximately 1.6 wt% to approximately 3.0 wt%, approximately 1.6 wt% to approximately 2.8 wt%, approximately 1.6 wt% to approximately 2.6 wt%, approximately 1.6 wt% to approximately 2.4 wt%, approximately 1.6 wt% to approximately 2.2 wt%, approximately 1.6 wt% to approximately 2.0 wt%, approximately 1.6 wt% to approximately 1.8 wt%, approximately 1.8 wt% to approximately 3.0 wt%, approximately 1.8 wt% to approximately 2.8 wt%, approximately 1.8 wt% to approximately 2.6 wt%, approximately 1.8 wt% to approximately 2.4 wt%, approximately 1.8 wt% to approximately 2.2% by weight, approximately 1.8% by weight to approximately 2.0% by weight, approximately 2.0% by weight to approximately 3.0% by weight, approximately 2.0% by weight to approximately 2.8% by weight, approximately 2.0% by weight to approximately 2.6% by weight, approximately 2.0% by weight to approximately 2.4% by weight, approximately 2.0% by weight to approximately 2.2% by weight, approximately 2.2% by weight to approximately 3.0% by weight, approximately 2.2% by weight to approximately 2.8% by weight, approximately 2.2% by weight to approximately 2.6% by weight, approximately 2.2% by weight to approximately 2.4% by weight, approximately 2.4% by weight to approximately 3.0% by weight, approximately 2.4% by weight to approximately 2.8% by weight, approximately 2.6% by weight to approximately 2.8% by weight, or approximately 2.8% by weight to approximately 3.0% by weight of silicon. In some embodiments, the weld metal or the core of the metal-cored wire contains approximately 0.1 wt%, approximately 0.2 wt%, approximately 0.3 wt%, approximately 0.4 wt%, approximately 0.5 wt%, approximately 0.6 wt%, approximately 0.7 wt%, approximately 0.8 wt%, approximately 0.9 wt%, approximately 1.0 wt%, approximately 1.1 wt%, approximately 1.2 wt%, approximately 1.3 wt%, approximately 1.4 wt%, approximately 1.5 wt%, approximately 1.6 wt%, approximately 1.7 wt%, approximately 1.8 wt%, approximately 1.9 wt%, approximately 2.0 wt%, approximately 2.1 wt%, approximately 2.2 wt%, approximately 2.3 wt%, approximately 2.4 wt%, approximately 2.5 wt%, approximately 2.6 wt%, approximately 2.7 wt%, approximately 2.8 wt%, approximately 2.9 wt%, or approximately 3.0 wt% carbon.

[0084] In some embodiments, the weld metal or the core of the metal-cored wire may further comprise chromium, nickel, molybdenum, tungsten, copper, niobium, vanadium, titanium, tantalum, nitrogen, and / or boron. The amounts described in more detail below further enhance the strength, corrosion resistance, and toughness of the weld metal.

[0085] Chromium is a ferrite stabilizer; when added to high-manganese steel weld metal, it enhances the formation of the ferrite phase during cooling and improves corrosion resistance. Chromium is also a strong carbide forming agent and promotes the formation of carbides (such as M2C and M...). 23The precipitation of C6 depends on the alloy level and / or heat treatment temperature. Furthermore, the addition of chromium is generally important for enhanced corrosion resistance. Adding chromium to iron-manganese alloy systems reduces the coefficient of thermal expansion. However, excessive chromium addition can lead to the formation of coarse grain boundary carbides and reduced toughness. Chromium may be present in an amount less than or equal to about 8.0 wt% of the weld metal or the core of the metal-core welding wire. In one particular embodiment, chromium is from about 2.0 wt% to about 6.0 wt% of the weld metal or the core of the metal-core welding wire. In one particular embodiment, chromium is from about 2.0 wt% to about 6.0 wt%. In some embodiments, the weld metal or the core of the metal-cored welding wire comprises approximately 0.0 wt% to approximately 8.0 wt%, approximately 0.0 wt% to approximately 7.5 wt%, approximately 0.0 wt% to approximately 7.0 wt%, approximately 0.0 wt% to approximately 6.5 wt%, approximately 0.0 wt% to approximately 6.0 wt%, approximately 0.0 wt% to approximately 5.5 wt%, approximately 0.0 wt% to approximately 5.0 wt%, approximately 0.0 wt% to approximately 4.5 wt%, approximately 0.0 wt% to approximately 4.0 wt%, and approximately 0.0 wt% to approximately 3. 5% by weight, from about 0.0% to about 3.0% by weight, from about 0.0% to about 2.5% by weight, from about 0.0% to about 2.0% by weight, from about 0.0% to about 1.5% by weight, from about 0.0% to about 1.0% by weight, from about 0.5% to about 8.0% by weight, from about 0.5% to about 7.5% by weight, from about 0.5% to about 7.0% by weight, from about 0.5% to about 6.5% by weight, from about 0.5% to about 6.0% by weight, from about 0.5% to about 5%. 5% by weight, approximately 0.5% to approximately 5.0% by weight, approximately 0.5% to approximately 4.5% by weight, approximately 0.5% to approximately 4.0% by weight, approximately 0.5% to approximately 3.5% by weight, approximately 0.5% to approximately 3.0% by weight, approximately 0.5% to approximately 2.5% by weight, approximately 0.5% to approximately 2.0% by weight, approximately 0.5% to approximately 1.5% by weight, approximately 0.5% to approximately 1.0% by weight, approximately 1.0% to approximately 8.0% by weight, approximately 1.0% to approximately 7%. 5% by weight, approximately 1.0% to approximately 7.0% by weight, approximately 1.0% to approximately 6.5% by weight, approximately 1.0% to approximately 6.0% by weight, approximately 1.0% to approximately 5.5% by weight, approximately 1.0% to approximately 5.0% by weight, approximately 1.0% to approximately 4.5% by weight, approximately 1.0% to approximately 4.0% by weight, approximately 1.0% to approximately 3.5% by weight, approximately 1.0% to approximately 3.0% by weight, approximately 1.0% to approximately 2.5% by weight, approximately 1.0% to approximately 2.0% by weight, approximately 1.0% to approximately 1.5% by weight, approximately 1.5% to approximately 8.0% by weight, approximately 1.5% to approximately 7.5% by weight, approximately 1.5% to approximately 7.0% by weight, approximately 1.5% to approximately 6.5% by weight, approximately 1.5% to approximately 6.0% by weight, approximately 1.5% to approximately 5.5% by weight, approximately 1.5% to approximately 5.0% by weight, approximately 1.5% to approximately 4.5% by weight, approximately 1.5% to approximately 4.0% by weight, approximately 1.5% to approximately 3.5% by weight, approximately 1.5% to approximately 3.0% by weight, approximately 1.5% to approximately 2.5% by weight, approximately 1.5% to approximately... Approximately 2.0 wt%, approximately 2.0 wt% to approximately 8.0 wt%, approximately 2.0 wt% to approximately 7.5 wt%, approximately 2.0 wt% to approximately 7.0 wt%, approximately 2.0 wt% to approximately 6.5 wt%, approximately 2.0 wt% to approximately 6.0 wt%, approximately 2.0 wt% to approximately 5.5 wt%, approximately 2.0 wt% to approximately 5.0 wt%, approximately 2.0 wt% to approximately 4.5 wt%, approximately 2.0 wt% to approximately 4.0 wt%, approximately 2.0 wt% to approximately 3.5 wt%, approximately 2.0 wt% to approximately 3.0 wt%, approximately 2.0 wt% to approximately 2.5 wt%, approximately 2.5 wt% to approximately 8.0 wt%, approximately 2.5 wt%. Up to approximately 7.5% by weight, approximately 2.5% by weight to approximately 7.0% by weight, approximately 2.5% by weight to approximately 6.5% by weight, approximately 2.5% by weight to approximately 6.0% by weight, approximately 2.5% by weight to approximately 5.5% by weight, approximately 2.5% by weight to approximately 5.0% by weight, approximately 2.5% by weight to approximately 4.5% by weight, approximately 2.5% by weight to approximately 4.0% by weight, approximately 2.5% by weight to approximately 3.5% by weight, approximately 2.5% by weight to approximately 3.0% by weight, approximately 3.0% by weight to approximately 8.0% by weight, approximately 3.0% by weight to approximately 7.5% by weight, approximately 3.0% by weight to approximately 7.0% by weight, approximately 3.0% by weight to approximately 6.5% by weight, approximately 3.0% by weight From approximately 6.0% by weight, from approximately 3.0% by weight to approximately 5.5% by weight, from approximately 3.0% by weight to approximately 5.0% by weight, from approximately 3.0% by weight to approximately 4.5% by weight, from approximately 3.0% by weight to approximately 4.0% by weight, from approximately 3.0% by weight to approximately 3.5% by weight, from approximately 3.5% by weight to approximately 8.0% by weight, from approximately 3.5% by weight to approximately 7.5% by weight, from approximately 3.5% by weight to approximately 7.0% by weight, from approximately 3.5% by weight to approximately 6.5% by weight, from approximately 3.5% by weight to approximately 6.0% by weight, from approximately 3.5% by weight to approximately 5.5% by weight, from approximately 3.5% by weight to approximately 5.0% by weight, from approximately 3.5% by weight to approximately 4.5% by weight, and approximately 3.5% by weight to about 4.0% by weight, about 4.0% by weight to about 8.0% by weight, about 4.0% by weight to about 7.5% by weight, about 4.0% by weight to about 7.0% by weight, about 4.0% by weight to about 6.5% by weight, about 4.0% by weight to about 6.0% by weight, about 4.0% by weight to about 5.5% by weight, about 4.0% by weight to about 5.0% by weight, about 4.0% by weight to about 4.5% by weight, about 4.5% by weight to about 8.0% by weight, about 4.5% by weight to about 7.5% by weight, about 4.5% by weight to about 7.0% by weight, about 4.5% by weight to about 6.5% by weight, about 4.5% by weight to about 6.0% by weight, about 4.5% by weight to about 5.5% by weight, about 4.5% by weight to about 5.0% by weight, about 5.0% by weight to about 8.0% by weight, about 5.0% by weight to about 7.5% by weight, about 5.0% by weight to about 7.0% by weight. 0.0 wt%, approximately 5.0 wt% to approximately 6.5 wt%, approximately 5.0 wt% to approximately 6.0 wt%, approximately 5.0 wt% to approximately 5.5 wt%, approximately 5.5 wt% to approximately 8.0 wt%, approximately 5.5 wt% to approximately 7.5 wt%, approximately 5.5 wt% to approximately 7.0 wt%, approximately 5.5 wt% to approximately 6.5 wt%, approximately 5.5 wt% to approximately 6.0 wt%, approximately 6.0 wt% to approximately 8.0 wt%, approximately 6.0 wt% to approximately 7.5 wt%, approximately 6.0 wt% to approximately 7.0 wt%, approximately 6.0 wt% to approximately 6.5 wt%, approximately 6.5 wt% to approximately 8.0 wt%, approximately 6.5 wt% to approximately 7.5 wt%, approximately 6.5 wt% to approximately 7.0 wt%, approximately 7.0 wt% to approximately 8.0 wt%, approximately 7.0 wt% to approximately 7.5 wt%, or approximately 7.5 wt% to approximately 8.0 wt% of chromium. In some embodiments, the weld metal or the core of the metal-cored wire contains approximately 0.25 wt%, approximately 0.5 wt%, approximately 0.75 wt%, approximately 1.0 wt%, approximately 1.25 wt%, approximately 1.5 wt%, approximately 1.75 wt%, approximately 2.0 wt%, approximately 2.25 wt%, approximately 2.5 wt%, approximately 2.75 wt%, approximately 3.0 wt%, approximately 3.25 wt%, approximately 3.5 wt%, approximately 3.75 wt%, approximately 4.0 wt%, approximately 4.5 wt%, approximately 4.25 wt%, approximately 4.75 wt%, approximately 5.0 wt%, approximately 5.25 wt%, approximately 5.5 wt%, approximately 5.75 wt%, approximately 6.0 wt%, approximately 6.25 wt%, approximately 6.5 wt%, approximately 6.75 wt%, approximately 7.0 wt%, approximately 7.25 wt%, approximately 7.5 wt%, approximately 7.75 wt%, or approximately 8.0 wt% carbon.

[0086] The addition of nickel provides additional austenitic stability and improves weld metal toughness through solid solution strengthening. Nickel also significantly improves the corrosion resistance and low-temperature toughness of the weld metal. Nickel may be present in up to 6% by weight of the weld metal or the core of the metal-cored wire. In another embodiment, nickel is present in up to 5% by weight. In some embodiments, nickel is present in amounts from about 0.2% by weight to about 6% by weight or from about 0.2% by weight to about 5% by weight. Higher amounts of nickel addition may result in a decrease in strength. In a particular embodiment, nickel is present in amounts from about 0.0% by weight to about 5.0% by weight. In some embodiments, the weld metal or the core of the metal-cored welding wire comprises approximately 0.0 wt% to approximately 6.0 wt%, approximately 0.0 wt% to approximately 5.5 wt%, approximately 0.0 wt% to approximately 5.0 wt%, approximately 0.0 wt% to approximately 4.5 wt%, approximately 0.0 wt% to approximately 4.0 wt%, approximately 0.0 wt% to approximately 3.5 wt%, approximately 0.0 wt% to approximately 3.0 wt%, approximately 0.0 wt% to approximately 2.5 wt%, approximately 0.0 wt% to approximately 2.0 wt%, and approximately 0.0 wt% to approximately 1.5 wt%. Approximately 0.0% to approximately 1.0% by weight, approximately 0.5% to approximately 6.0% by weight, approximately 0.5% to approximately 5.5% by weight, approximately 0.5% to approximately 5.0% by weight, approximately 0.5% to approximately 4.5% by weight, approximately 0.5% to approximately 4.0% by weight, approximately 0.5% to approximately 3.5% by weight, approximately 0.5% to approximately 3.0% by weight, approximately 0.5% to approximately 2.5% by weight, approximately 0.5% to approximately 2.0% by weight, approximately 0.5% to approximately 1.5% by weight, approximately 0. 5% by weight to about 1.0% by weight, about 1.0% by weight to about 6.0% by weight, about 1.0% by weight to about 5.5% by weight, about 1.0% by weight to about 5.0% by weight, about 1.0% by weight to about 4.5% by weight, about 1.0% by weight to about 4.0% by weight, about 1.0% by weight to about 3.5% by weight, about 1.0% by weight to about 3.0% by weight, about 1.0% by weight to about 2.5% by weight, about 1.0% by weight to about 2.0% by weight, about 1.0% by weight to about 1.5% by weight, about 1.5% by weight Up to about 6.0 wt%, about 1.5 wt% to about 5.5 wt%, about 1.5 wt% to about 5.0 wt%, about 1.5 wt% to about 4.5 wt%, about 1.5 wt% to about 4.0 wt%, about 1.5 wt% to about 3.5 wt%, about 1.5 wt% to about 3.0 wt%, about 1.5 wt% to about 2.5 wt%, about 1.5 wt% to about 2.0 wt%, about 2.0 wt% to about 6.0 wt%, about 2.0 wt% to about 5.5 wt%, about 2.0 wt% to about 5.0% by weight, approximately 2.0% to approximately 4.5% by weight, approximately 2.0% to approximately 4.0% by weight, approximately 2.0% to approximately 3.5% by weight, approximately 2.0% to approximately 3.0% by weight, approximately 2.0% to approximately 2.5% by weight, approximately 2.5% to approximately 6.0% by weight, approximately 2.5% to approximately 5.5% by weight, approximately 2.5% to approximately 5.0% by weight, approximately 2.5% to approximately 4.5% by weight, approximately 2.5% to approximately 4.0% by weight, approximately 2.5% to approximately 3.5% by weight, approximately 2.5% to approximately 3.0% by weight, approximately 3.0% to approximately 6.0% by weight, approximately 3.0% to approximately 5.5% by weight, approximately 3.0% to approximately 5.0% by weight, approximately 3.0% to approximately 4.5% by weight, approximately 3.0% by weight Up to about 4.0 wt%, about 3.0 wt% to about 3.5 wt%, about 3.5 wt% to about 6.0 wt%, about 3.5 wt% to about 5.5 wt%, about 3.5 wt% to about 5.0 wt%, about 3.5 wt% to about 4.5 wt%, about 3.5 wt% to about 4.0 wt%, about 4.0 wt% to about 6.0 wt%, about 4.0 wt% to about 5.5 wt%, about 4.0 wt% to about 5.0 wt%, about 4.0 wt% to about 4.5 wt%, about 4.5 wt% to about 6.0 wt%, about 4.5 wt% to about 5.5 wt%, about 4.5 wt% to about 5.0 wt%, about 5.0 wt% to about 6.0 wt%, about 5.0 wt% to about 5.5 wt%, or about 5.5 wt% to about 6.0 wt% of nickel. In some embodiments, the weld metal or the core of the metal-cored welding wire contains approximately 0.25 wt%, approximately 0.5 wt%, approximately 0.75 wt%, approximately 1.0 wt%, approximately 1.25 wt%, approximately 1.5 wt%, approximately 1.75 wt%, approximately 2.0 wt%, approximately 2.25 wt%, approximately 2.5 wt%, approximately 2.75 wt%, approximately 3.0 wt%, approximately 3.25 wt%, approximately 3.5 wt%, approximately 3.75 wt%, approximately 4.0 wt%, approximately 4.5 wt%, approximately 4.25 wt%, approximately 4.75 wt%, approximately 5.0 wt%, approximately 5.25 wt%, approximately 5.5 wt%, approximately 5.75 wt%, or approximately 6.0 wt% nickel.

[0087] Molybdenum (Mo) and tungsten (W) are ferrite stabilizers and stable carbide forming agents. Molybdenum and tungsten provide significant solid solution strengthening and refine the solidified cell structure through solute drag. Molybdenum may be present in up to 6% by weight of the weld metal or the core of a metal-core wire. In one particular embodiment, molybdenum is present in the amount of about 0.5% by weight to about 3.0% by weight. In another embodiment, molybdenum is present in the amount of up to 5% by weight. In some embodiments, molybdenum is present in the amount of about 0.2% by weight to about 6% by weight, or about 0.2% by weight to about 5% by weight. Higher amounts of molybdenum added may result in a decrease in strength. In one particular embodiment, molybdenum is present in the amount of about 0.0% by weight to about 5.0% by weight. In some embodiments, the weld metal or the core of the metal-cored welding wire comprises approximately 0.0 wt% to approximately 5.5 wt%, approximately 0.0 wt% to approximately 5.0 wt%, approximately 0.0 wt% to approximately 4.5 wt%, approximately 0.0 wt% to approximately 4.0 wt%, approximately 0.0 wt% to approximately 3.5 wt%, approximately 0.0 wt% to approximately 3.0 wt%, approximately 0.0 wt% to approximately 2.5 wt%, approximately 0.0 wt% to approximately 2.0 wt%, approximately 0.0 wt% to approximately 1.5 wt%, and approximately 0.0 wt%. From about 1.0 wt%, from about 0.5 wt% to about 6.0 wt%, from about 0.5 wt% to about 5.5 wt%, from about 0.5 wt% to about 5.0 wt%, from about 0.5 wt% to about 4.5 wt%, from about 0.5 wt% to about 4.0 wt%, from about 0.5 wt% to about 3.5 wt%, from about 0.5 wt% to about 3.0 wt%, from about 0.5 wt% to about 2.5 wt%, from about 0.5 wt% to about 2.0 wt%, from about 0.5 wt% to about 1.5 wt%, from about 0. 5% by weight to about 1.0% by weight, about 1.0% by weight to about 6.0% by weight, about 1.0% by weight to about 5.5% by weight, about 1.0% by weight to about 5.0% by weight, about 1.0% by weight to about 4.5% by weight, about 1.0% by weight to about 4.0% by weight, about 1.0% by weight to about 3.5% by weight, about 1.0% by weight to about 3.0% by weight, about 1.0% by weight to about 2.5% by weight, about 1.0% by weight to about 2.0% by weight, about 1.0% by weight to about 1.5% by weight Approximately 1.5% to approximately 6.0% by weight, approximately 1.5% to approximately 5.5% by weight, approximately 1.5% to approximately 5.0% by weight, approximately 1.5% to approximately 4.5% by weight, approximately 1.5% to approximately 4.0% by weight, approximately 1.5% to approximately 3.5% by weight, approximately 1.5% to approximately 3.0% by weight, approximately 1.5% to approximately 2.5% by weight, approximately 1.5% to approximately 2.0% by weight, approximately 2.0% to approximately 6.0% by weight, approximately 2.0% to approximately 5%.5% by weight, approximately 2.0% to approximately 5.0% by weight, approximately 2.0% to approximately 4.5% by weight, approximately 2.0% to approximately 4.0% by weight, approximately 2.0% to approximately 3.5% by weight, approximately 2.0% to approximately 3.0% by weight, approximately 2.0% to approximately 2.5% by weight, approximately 2.5% to approximately 6.0% by weight, approximately 2.5% to approximately 5.5% by weight, approximately 2.5% to approximately 5.0% by weight, approximately 2.5% to approximately 4.5% by weight, approximately 2.5% to approximately 4.0% by weight, approximately 2.5% to approximately 3.5% by weight, approximately 2.5% to approximately 3.0% by weight, approximately 3.0% to approximately 6.0% by weight, approximately 3.0% to approximately 5.5% by weight, approximately 3.0% to approximately 5.0% by weight, approximately 3.0% to approximately 4.5% by weight. Molybdenum, approximately 3.0% to approximately 4.0% by weight, approximately 3.0% to approximately 3.5% by weight, approximately 3.5% to approximately 6.0% by weight, approximately 3.5% to approximately 5.5% by weight, approximately 3.5% to approximately 5.0% by weight, approximately 3.5% to approximately 4.5% by weight, approximately 3.5% to approximately 4.0% by weight, approximately 4.0% to approximately 6.0% by weight, approximately 4.0% to approximately 5.5% by weight, approximately 4.0% to approximately 5.0% by weight, approximately 4.0% to approximately 4.5% by weight, approximately 4.5% to approximately 6.0% by weight, approximately 4.5% to approximately 5.5% by weight, approximately 4.5% to approximately 5.0% by weight, approximately 5.0% to approximately 6.0% by weight, or approximately 5.5% to approximately 6.0% by weight. In some embodiments, the weld metal or the core of the metal-cored welding wire contains approximately 0.25 wt%, approximately 0.5 wt%, approximately 0.75 wt%, approximately 1.0 wt%, approximately 1.25 wt%, approximately 1.5 wt%, approximately 1.75 wt%, approximately 2.0 wt%, approximately 2.25 wt%, approximately 2.5 wt%, approximately 2.75 wt%, approximately 3.0 wt%, approximately 3.25 wt%, approximately 3.5 wt%, approximately 3.75 wt%, approximately 4.0 wt%, approximately 4.5 wt%, approximately 4.25 wt%, approximately 4.75 wt%, approximately 5.0 wt%, approximately 5.25 wt%, approximately 5.5 wt%, approximately 5.75 wt%, or approximately 6.0 wt% molybdenum.

[0088] Tungsten may be present in a maximum of 5% by weight of the weld metal or the core of the metal-cored wire. In one particular embodiment, tungsten is present in an amount from about 0.1% to about 2.0% by weight. In some embodiments, the weld metal or the core of the metal-cored wire contains about 0.0% to about 4.5% by weight, about 0.0% to about 4.0% by weight, about 0.0% to about 3.5% by weight, about 0.0% to about 3.0% by weight, about 0.0% to about 2.5% by weight, about 0.0% to about 2.0% by weight, about 0.0% to about 1.5% by weight, about 0.0% to about 1.0% by weight, about 0.5% to about 5.0% by weight, about 0.5% to about 4.5% by weight, about 0.5% to about 4.0% by weight, and about 0.5% to about 3% by weight. 5% by weight, from about 0.5% by weight to about 3.0% by weight, from about 0.5% by weight to about 2.5% by weight, from about 0.5% by weight to about 2.0% by weight, from about 0.5% by weight to about 1.5% by weight, from about 0.5% by weight to about 1.0% by weight, from about 1.0% by weight to about 5.0% by weight, from about 1.0% by weight to about 4.5% by weight, from about 1.0% by weight to about 4.0% by weight, from about 1.0% by weight to about 3.5% by weight, from about 1.0% by weight to about 3.0% by weight, from about 1.0% by weight to about 2.5% by weight, from about 1.0% by weight to about 2.0% by weight, from about 1.0% by weight to about 1%. 5% by weight, approximately 1.5% to approximately 5.0% by weight, approximately 1.5% to approximately 4.5% by weight, approximately 1.5% to approximately 4.0% by weight, approximately 1.5% to approximately 3.5% by weight, approximately 1.5% to approximately 3.0% by weight, approximately 1.5% to approximately 2.5% by weight, approximately 1.5% to approximately 2.0% by weight, approximately 2.0% to approximately 5.0% by weight, approximately 2.0% to approximately 4.5% by weight, approximately 2.0% to approximately 4.0% by weight, approximately 2.0% to approximately 3.5% by weight, approximately 2.0% to approximately 3.0% by weight, approximately 2.0% to approximately 2.0% by weight. 5% by weight, approximately 2.5% to approximately 5.0% by weight, approximately 2.5% to approximately 4.5% by weight, approximately 2.5% to approximately 4.0% by weight, approximately 2.5% to approximately 3.5% by weight, approximately 2.5% to approximately 3.0% by weight, approximately 3.0% to approximately 5.0% by weight, approximately 3.0% to approximately 4.5% by weight, approximately 3.0% to approximately 4.0% by weight, approximately 3.0% to approximately 3.5% by weight, approximately 3.5% to approximately 5.0% by weight, approximately 3.5% to approximately 4.5% by weight, approximately 3.5% to approximately 4.0% by weight, approximately 4.0% to approximately 5.0% by weight.The weld metal or the core of the metal-cored wire contains approximately 0.25 wt%, approximately 0.5 wt%, approximately 0.75 wt%, approximately 1.0 wt%, approximately 1.25 wt%, approximately 1.5 wt%, approximately 1.75 wt%, approximately 2.0 wt%, approximately 2.25 wt%, approximately 2.5 wt%, approximately 2.75 wt%, approximately 3.0 wt%, approximately 3.25 wt%, approximately 3.5 wt%, approximately 3.75 wt%, approximately 4.0 wt%, approximately 4.5 wt%, approximately 4.25 wt%, approximately 4.75 wt%, or approximately 5.0 wt% tungsten.

[0089] Copper is an austenitic stabilizer that strengthens weld metal through solution hardening. In one embodiment, copper may be present in up to about 4% by weight of the weld metal or the core of a metal-core welding wire. In a particular embodiment, copper is from about 0.0% by weight to about 2.0% by weight. In some embodiments, the weld metal or the core of the metal-cored welding wire comprises approximately 0.0 wt% to approximately 4.0 wt%, approximately 0.0 wt% to approximately 3.5 wt%, approximately 0.0 wt% to approximately 3.0 wt%, approximately 0.0 wt% to approximately 2.5 wt%, approximately 0.0 wt% to approximately 2.0 wt%, approximately 0.0 wt% to approximately 1.5 wt%, approximately 0.0 wt% to approximately 1.0 wt%, approximately 0.5 wt% to approximately 4.0 wt%, approximately 0.5 wt% to approximately 3.5 wt%, approximately 0.5 wt% to approximately 3.0 wt%, approximately 0.5 wt% to approximately 2.5 wt%, approximately 0.5 wt% to approximately 2.0 wt%, approximately 0.5 wt% to approximately 1.5 wt%, approximately 0.5 wt% to approximately 1.0 wt%, approximately 1.0 wt% to approximately 4.0 wt%, approximately 1.0 wt% to approximately 3.5 wt%, and approximately 1.0 wt% to approximately 3.0 wt%. Approximately 1.0 wt% to approximately 2.5 wt%, approximately 1.0 wt% to approximately 2.0 wt%, approximately 1.0 wt% to approximately 1.5 wt%, approximately 1.5 wt% to approximately 4.0 wt%, approximately 1.5 wt% to approximately 3.5 wt%, approximately 1.5 wt% to approximately 3.0 wt%, approximately 1.5 wt% to approximately 2.5 wt%, approximately 1.5 wt% to approximately 2.0 wt%, approximately 2.0 wt% to approximately 4.0 wt%, approximately 2.0 wt% to approximately 3.5 wt%, approximately 2.0 wt% to approximately 3.0 wt%, approximately 2.0 wt% to approximately 2.5 wt%, approximately 2.5 wt% to approximately 4.0 wt%, approximately 2.5 wt% to approximately 3.5 wt%, approximately 2.5 wt% to approximately 3.0 wt%, approximately 3.0 wt% to approximately 4.0 wt%, approximately 3.0 wt% to approximately 3.5 wt%, or approximately 3.5 wt% to approximately 4.0 wt% of copper. In some embodiments, the weld metal or the core of the metal-cored welding wire contains about 0.25 wt%, about 0.5 wt%, about 0.75 wt%, about 1.0 wt%, about 1.25 wt%, about 1.5 wt%, about 1.75 wt%, about 2.0 wt%, about 2.25 wt%, about 2.5 wt%, about 2.75 wt%, about 3.0 wt%, about 3.25 wt%, about 3.5 wt%, about 3.75 wt%, or about 4.0 wt% copper.

[0090] Nitrogen is a strong austenitic stabilizer that enhances the strength of weld metal through solid solution strengthening. However, higher amounts of nitrogen can cause porosity and reduced toughness in the weld metal. Appropriate nitrogen addition can reduce the carbon content and the tendency for solidification cracking in the weld metal without compromising its strength. Nitrogen addition can also enhance corrosion resistance. Nitrogen can be present in the weld metal or the core of a metal-cored wire at a maximum of about 0.4% by weight. Excessive nitrogen causes the formation of coarse nitrides and weld defects such as porosity. In one particular embodiment, the weld metal or the core of the metal-cored wire contains about 0.01% to about 0.3% by weight of nitrogen. In some embodiments, the weld metal or the core of the metal-cored wire contains about 0.0 wt% to about 0.4 wt%, about 0.0 wt% to about 0.3 wt%, about 0.0 wt% to about 0.2 wt%, about 0.1 wt% to about 0.4 wt%, about 0.1 wt% to about 0.3 wt%, about 0.1 wt% to about 0.2 wt%, about 0.2 wt% to about 0.4 wt%, or about 0.2 wt% to about 0.3 wt% nitrogen. In some embodiments, the weld metal or the core of the metal-cored wire contains about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, or about 0.4 wt% nitrogen.

[0091] Niobium, vanadium, tantalum, and titanium are strong carbide / nitride forming agents and effective elements for improving weld strength. Tantalum can be added to act as a solid solution strengthening agent. For grain refinement and precipitation hardening purposes, small amounts of titanium and niobium can be added to strengthen the weld metal. Niobium, vanadium, tantalum, and titanium may each be present independently as a maximum of about 2% by weight in the weld metal or the core of the metal-core welding wire. That is, each element may be present as a maximum of about 2% by weight. In a particular embodiment, niobium, vanadium, tantalum, and titanium may each be present individually and independently as a maximum of about 1.0% by weight. In some embodiments, the core of the weld metal or metal-cored wire comprises, individually (and independently optional) from about 0.0 wt% to about 2.0 wt%, from about 0.0 wt% to about 1.8 wt%, from about 0.0 wt% to about 1.6 wt%, from about 0.0 wt% to about 1.4 wt%, from about 0.0 wt% to about 1.2 wt%, from about 0.0 wt% to about 1.0 wt%, from about 0.0 wt% to about 0.8 wt%, from about 0.0 wt% to about 0.6 wt%, from about 0.0 wt% to about 0.4 wt%, and about 0.0 wt%. Up to about 0.2 wt%, about 0.2 wt% to about 2.0 wt%, about 0.2 wt% to about 1.8 wt%, about 0.2 wt% to about 1.6 wt%, about 0.2 wt% to about 1.4 wt%, about 0.2 wt% to about 1.2 wt%, about 0.2 wt% to about 1.0 wt%, about 0.2 wt% to about 0.8 wt%, about 0.2 wt% to about 0.6 wt%, about 0.2 wt% to about 0.4 wt%, about 0.4 wt% to about 2.0 wt%, about 0.4 wt% to about 1.8 wt% %, from about 0.4 wt% to about 1.6 wt%, from about 0.4 wt% to about 1.4 wt%, from about 0.4 wt% to about 1.2 wt%, from about 0.4 wt% to about 1.0 wt%, from about 0.4 wt% to about 0.8 wt%, from about 0.4 wt% to about 0.6 wt%, from about 0.6 wt% to about 2.0 wt%, from about 0.6 wt% to about 1.8 wt%, from about 0.6 wt% to about 1.6 wt%, from about 0.6 wt% to about 1.4 wt%, from about 0.6 wt% to about 1.2 wt%, from about 0.6 wt%. From % by weight to about 1.0 wt%, from about 0.6 wt% to about 0.8 wt%, from about 0.8 wt% to about 2.0 wt%, from about 0.8 wt% to about 1.8 wt%, from about 0.8 wt% to about 1.6 wt%, from about 0.8 wt% to about 1.4 wt%, from about 0.8 wt% to about 1.2 wt%, from about 0.8 wt% to about 1.0 wt%, from about 1.0 wt% to about 2.0 wt%, from about 1.0 wt% to about 1.8 wt%, from about 1.0 wt% to about 1.6 wt%, from about 1.0 wt% to about 1.Niobium, vanadium, and / or titanium in the range of 4 wt%, from about 1.0 wt% to about 1.2 wt%, from about 1.2 wt% to about 2.0 wt%, from about 1.2 wt% to about 1.8 wt%, from about 1.2 wt% to about 1.6 wt%, from about 1.2 wt% to about 1.4 wt%, from about 1.4 wt% to about 2.0 wt%, from about 1.4 wt% to about 1.8 wt%, from about 1.4 wt% to about 1.6 wt%, from about 1.6 wt% to about 2.0 wt%, from about 1.6 wt% to about 1.8 wt%, or from about 1.8 wt% to about 2.0 wt%. In some embodiments, the weld metal or the core of the metal-cored wire comprises, individually (and optionally independently) about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, about 1.0 wt%, about 1.1 wt%, about 1.2 wt%, about 1.3 wt%, about 1.4 wt%, about 1.5 wt%, about 1.6 wt%, about 1.7 wt%, about 1.8 wt%, about 1.9 wt%, or about 2.0 wt% of niobium, vanadium, and / or titanium.

[0092] Sulfur and phosphorus are impurities and are not intentionally added. These elements are controlled by limiting their amounts in welding consumables. The amounts of sulfur and phosphorus must be controlled to avoid weld solidification cracking. Therefore, in one embodiment, sulfur is less than about 0.3% by weight of the weld metal or the core of the metal-cored wire. Sulfur may be less than about 0.01% by weight. In another embodiment, phosphorus is less than about 0.3% by weight of the weld metal or the core of the metal-cored wire. Phosphorus may be less than about 0.02% by weight. In a particular embodiment, phosphorus is less than about 0.01% by weight.

[0093] In some embodiments, the weld metal or the core of the metal-cored welding wire contains about 0.0 wt% to about 1.0 wt% boron. In a particular embodiment, the boron content is about 0.01 wt% to about 0.4 wt%. In some embodiments, boron is present in amounts of about 0.0 wt% to about 1.0 wt%, about 0.0 wt% to about 0.8 wt%, about 0.0 wt% to about 0.6 wt%, about 0.0 wt% to about 0.4 wt%, about 0.0 wt% to about 0.2 wt%, about 0.05 wt% to about 1.0 wt%, about 0.05 wt% to about 0.8 wt%, about 0.05 wt% to about 0.6 wt%, about 0.5 wt% to about 0.4 wt%, about 0.5 wt% to about 0.2 wt%, about 0.1 wt% to about 1.0 wt%, about 0.1 wt% to about 0.8 wt%, and about 0.1 wt% to about 1.0 wt%. It is present in the weld metal or the core of the metal-core welding wire in about 0.6 wt%, about 0.1 wt% to about 0.4 wt%, about 0.1 wt% to about 0.2 wt%, about 0.2 wt% to about 1.0 wt%, about 0.2 wt% to about 0.8 wt%, about 0.2 wt% to about 0.6 wt%, about 0.2 wt% to about 0.4 wt%, about 0.4 wt% to about 1.0 wt%, about 0.4 wt% to about 0.8 wt%, about 0.4 wt% to about 0.6 wt%, about 0.6 wt% to about 1.0 wt%, or about 0.8 wt% to about 1.0 wt%. In some embodiments, boron is present in about 0.01 wt%, about 0.05 wt%, about 0.1 wt%, about 0.2 wt%, about 0.3 wt%, about 0.4 wt%, about 0.5 wt%, about 0.6 wt%, about 0.7 wt%, about 0.8 wt%, about 0.9 wt%, or about 1.0 wt%.

[0094] In one particular embodiment, the weld metal is a predominant austenitic phase having finely dispersed secondary phases of carbides, nitrides, carbonitrides, and combinations thereof. The carbon and nitrogen content of the weld metal can be selected to provide a yield strength level ranging from approximately 60 ksi to approximately 130 ksi in the as-deposite condition without cold deformation. In one particular embodiment, the yield strength level of the weld metal in the deposited state without cold deformation is approximately 60 ksi to approximately 120 ksi, approximately 60 ksi to approximately 110 ksi, approximately 60 ksi to approximately 100 ksi, approximately 60 ksi to approximately 90 ksi, approximately 60 ksi to approximately 80 ksi, approximately 60 ksi to approximately 70 ksi, approximately 70 ksi to approximately 130 ksi, approximately 70 ksi to approximately 120 ksi, approximately 70 ksi to approximately 110 ksi, approximately 70 ksi to approximately 100 ksi, approximately 70 ksi to approximately 100 ksi, approximately 70 ksi to approximately 90 ksi, approximately 70 ksi to approximately 80 ksi, approximately 80 ksi to approximately 130 ksi, approximately 80 ksi to approximately 120 ksi, approximately 80 ksi to approximately 110 ksi, approximately 80 ksi to approximately 100 ksi, approximately 80 ksi to approximately 90 ksi, approximately 90 ksi to approximately 130 ksi. ksi, approximately 90 ksi to approximately 120 ksi, approximately 90 ksi to approximately 110 ksi, approximately 90 ksi to approximately 100 ksi, approximately 100 ksi to approximately 130 ksi, approximately 100 ksi to approximately 120 ksi, approximately 100 ksi to approximately 110 ksi, approximately 110 ksi to approximately 130 ksi, approximately 110 ksi to approximately 120 ksi, or approximately 120 ksi to approximately 130 ksi. In some embodiments, the weld metal in the deposited state without cold deformation has a yield strength level of approximately 60 ksi, approximately 65 ksi, approximately 70 ksi, approximately 75 ksi, approximately 80 ksi, approximately 85 ksi, approximately 90 ksi, approximately 95 ksi, approximately 100 ksi, approximately 105 ksi, approximately 110 ksi, approximately 115 ksi, approximately 120 ksi, approximately 125 ksi, or approximately 130 ksi.

[0095] Furthermore, enhanced alloying with strong carbide / nitride forming agents, such as titanium, tungsten, and tantalum (to form high-temperature carbides (e.g., TiC) to enhance strength through precipitation hardening) effectively reduces the carbon content in the liquid phase during weld solidification. This leads to reduced susceptibility to hot cracking and hinders the formation of coarse M2C and M2C at grain boundaries. 23C6 carbide precipitation. In one embodiment, the weld metal of this disclosure is predominantly austenitic. In another embodiment, the weld metal contains low amounts (e.g., less than 1 vol%) of inclusions (e.g., FeS and / or MnS). In one embodiment, the weld metal contains low amounts of impurities (e.g., sulfur and phosphorus as discussed above).

[0096] The aforementioned microstructural features are achieved through a careful combination of weld metal chemistry and welding parameters. Specifically, the stacking fault energy (SFE) depends on the alloy chemistry, and the SFE value corresponds to the type of transformation-induced plasticity (TRIP) and twinning-induced plasticity (TWIP) mechanisms occurring in high-manganese steel during deformation. High-manganese steel exhibits a rapid work hardening rate due to the TWIP and martensitic TRIP effects. Activation and specific active deformation mechanisms, triggered by the SFE value of the alloy, influence the strength and corrosion resistance of the weld metal. Plastic deformation primarily occurs through low SFE values ​​(e.g., less than 12 mJ / m). 2 Martensitic transformation at high SFE (e.g., above 35 mJ / m) and through twinning formation at moderate SFE. 2 Under these conditions, plasticity and strain hardening are controlled solely by dislocation slip. Therefore, the SFE value is an important parameter in consumable alloy design, as it is considered a strong predictor of tensile strength and corrosion resistance.

[0097] SFE depends on alloy chemistry and temperature. Inherent stacking faults can be represented as ε-martensite nuclei at two sites within the thickness. SFE includes both volumetric and surface energy contributions. The chemical and temperature dependence of SFE largely stems from the volumetric energy difference between ε-martensite and austenite. The volume free energy of the phases can be obtained from available databases. For example, Figure 2 The display shows the addition of each element to FeMn 12 C 0.6 The predicted SFE (Self-Fuel Effect) varies depending on the alloying elements added, with carbon exhibiting the strongest effect and manganese the smallest. However, when considering the interactions of multiple alloying elements, the chemical dependence of SFE is a complex and non-monotonic effect.

[0098] The deformation mechanism can be controlled by appropriately customizing the weld metal chemistry. For example, embodiments of this disclosure show that lean chemistry (lower alloy content) tends to promote martensitic phase transformation and twinning during deformation.

[0099] In one embodiment, the weld metal is strengthened by second-phase particles. That is, in one embodiment, the weld metal undergoes precipitation hardening. For example, the weld metal of this disclosure may include carbides, nitrides, borides, and / or oxides. The precipitation-hardened second-phase particles further improve the wear / corrosion resistance of the weld metal. It is believed that the second-phase particles inhibit dislocation migration during deformation, thereby increasing the strength of the alloy. Although the presence of carbides in the weld metal increases hardness, size and spatial distribution are important. Coarse carbide particles are largely responsible for mechanical failures in steel. Therefore, the weld metal may include fine, uniformly distributed carbides.

[0100] Carbides also enhance the TRIP and TWIP effects. The carbon concentration in the carbide phase is much higher than the average in steel. Through mass conservation, carbides significantly deplete the carbon in the surrounding matrix. Therefore, TRIP and TWIP are likely the dominant deformation mechanisms in the carbon depletion zone.

[0101] In another aspect of this disclosure, the weld metal has a nobleness similar to that of the base metal (i.e., the high-manganese steel to be welded). This minimizes preferential weld corrosion caused by galvanic corrosion. In one embodiment, the base metal and the weld metal have the same nobleness.

[0102] Electrochemical corrosion occurs between different regions of the weld due to local differences in composition and microstructure. Accelerated metal loss occurs in these regions if the weld metal (WM) and heat-affected zone (HAZ) are anodic to the base metal (PM). The small surface area of ​​the weld metal and HAZ relative to the large area of ​​the base metal exacerbates the severity of this form of corrosion. If the composition of the weld metal is chosen to be more inert than the high-Mn steel base material, or to have lower or near-negative reactivity to atoms or molecules at the interface with gases or liquids in a corrosive environment, it remains cathodic to reduce its corrosion rate. In practice, the chemical composition of the weld metal can be tailored to provide a more inert potential or a potential comparable to that of the high-Mn steel base material. For this purpose, and for its strength, the content of inert metal alloys (e.g., Cr) in the weld metal can be maintained at a higher level than the base metal or at a level comparable to that of the high-Mn steel base material. High Si addition in the weld metal is detrimental to achieving PWC resistance.

[0103] Solderability

[0104] Another aspect of this disclosure relates to a metal-cored welding wire for welding, for example, high-manganese steel. This novel ER-HMS weld metal provides the weldability required for manufacturing corrosion-resistant HMS slurry pipes via seam welding. This weldability is achieved through appropriate control of weld metal chemistry, welding process parameters, and weld joint design.

[0105] The metal-cored welding wire of this disclosure can be manufactured by bending a steel strip to create a sheath of steel (e.g., carbon steel or high-manganese steel). A metal powder with suitable chemistry as described above is filled into the circularly bent strip. The metal-cored welding wire filled with metal powder can be drawn to the desired diameter through a series of dies and subsequently annealed to relieve residual stress from the drawing and forming processes. Uniform filling of the tube with metal powder can be achieved using ultrasonic vibration. The bent strip is then further bent to form the tube constituting the metal-cored welding wire.

[0106] The pipe can be welded along its longitudinal seam. The welded core wire releases less moisture than the unwelded core wire. The unwelded core wire is prone to bending, making it difficult to adjust the wire feed to the target weld point. In another embodiment, the core wire includes a copper coating. The copper coating is easier to apply when the core wire has already been welded.

[0107] Furthermore, an electrolytic or chemical copper coating on the surface of the welding wire is preferred because it achieves uniform conductivity of current from the tip to the welding wire and thus enhances arc stability.

[0108] ER-HMS consumables have a similar manganese content to the corrosion-resistant HMS base metal, resulting in a weld metal microstructure—austenitic—that is similar to the base metal microstructure. This chemical compatibility prevents the formation of a martensitic phase at the weld metal / base metal interface. This eliminates the risk of potential problems such as cold cracking / hydrogen cracking.

[0109] Welding process parameters

[0110] Another aspect of this disclosure is a method for welding high-manganese steel. Reliable ER-HMS welds, produced at practical productivity levels for slurry pipe construction, can be achieved, for example, using submerged arc welding.

[0111] The method for welding high-manganese steel disclosed herein comprises: supplying at least one high-manganese steel part; supplying a metal-core welding wire as described above; immersing the at least one high-manganese steel part in slag and an arc stabilizer; and applying an electric current to the metal-core welding wire to produce a liquid alloy steel composition on the at least one high-manganese steel part. In some embodiments, the slag comprises: approximately 22-24% Al2O3, approximately 10-12% SiO2, approximately 6-8% MnO, approximately 22.5-24.5% CAF2, approximately 10.5-12.5% ​​MgO, approximately 11.5-13.5% CO2, approximately 2.5-4.5% CaO, approximately 0.5-2.5% Na2O, approximately 1.0-3.0% TiO2, approximately 0.5-1.6% ZrO2, approximately 0.3-1.3% K2O, approximately 0.2-1.2% Fe, approximately 0.2-2.2% Mn and / or approximately 0.1-1.0% Si. In other embodiments, the slag comprises at least one of the following: about 23.1% Al2O3, about 11.2% SiO2, about 7.1% MnO, about 23.4% CaF2, about 11.6% MgO, about 12.4% CO2, about 3.5% CaO, about 1.3% Na2O, about 2.1% TiO2, about 1.1% ZrO2, about 0.8% K2O, about 0.7% Fe, about 1.2% Mn, about 0.5% Si, or combinations thereof.

[0112] The ER-HMS weld metal described or included in this disclosure can be advantageously used in many systems / applications (e.g., oil, gas, and / or petrochemical equipment / systems, such as for reaction vessels, pipes, casings, packers, couplings, sucker rods, seals, wires, cables, bottom drill assemblies, pipes, valves, compressors, pumps, bearings, extruder barrels, molding dies, etc.), especially where corrosion / cracking resistance is important / required.

[0113] The appropriate application of the above-mentioned weld metal chemistry, welding methods and welding practices produces suitable ER-HMS welds with the microstructure and mechanical properties required for manufacturing HMS slurry pipes.

[0114] The present disclosure is further described with reference to the following embodiments; however, it is not intended to limit the scope of the disclosure. The following embodiments illustrate improved systems and methods for manufacturing or producing improved high-manganese steel welds (e.g., improved high-Mn weld compositions with enhanced corrosion resistance and / or cracking resistance).

[0115] Example

[0116] Example 1

[0117] Use as Figure 3 The two different carbon content levels shown are used to manufacture 24- to 30-inch diameter high-manganese steel pipes with wall thicknesses ranging from 19 mm to 20.6 mm via submerged arc welding. Seam welding was performed under the following conditions: a current of 530-630 A and a voltage of 27-31 V, a welding speed of 510-650 mm / min, and a heat input of 13-23 kJ / cm. Seam welds at higher carbon content exhibited increased yield strength and ultimate tensile strength compared to weld metals at lower carbon content.

[0118] Example 2

[0119] Six weld metals with different weld metal chemistry as shown in Table 1 were used to weld 19 mm thick high-manganese steel plates. The abrasion resistance of each weld metal was evaluated using a rotating rubber wheel test according to ASTM G65. Figure 4 As shown, weld metals with higher carbon content and enhanced Cr, Mo and W alloys (SL-1 to SL-5) exhibit improved wear resistance compared to weld metals with lower carbon content (SL-6) and API X70 carbon steel.

[0120] Table 1. Chemical composition of weld metal

[0121] Example 3

[0122] As shown in Table 2, high-manganese steel pipes with wall thicknesses of 19 mm to 20.6 mm and diameters of 24 to 30 inches were manufactured by submerged arc welding between ID and OD weld passes using two different chromium alloying levels. Seam weld test blocks cut from the welded pipes were immersed in an aqueous solution simulating an oil sand slurry pipe environment at 45°C, 1500 ppm NaCl, pH 8, and 8 ppm dissolved oxygen. Figure 5 As shown, ID weld beads with a higher Cr content than OD weld beads exhibit a lower corrosion grade and better resistance to preferential weld corrosion.

[0123] Table 2. Chemical composition of weld and substrate high-Mn steel obtained from inductively coupled plasma optical emission spectroscopy (ICP-OES) Detailed Implementation

[0124] According to one aspect, this disclosure provides a welding composition comprising: (b) 0.3% to 1.2% by weight of carbon; (c) 0.1% to 3.0% by weight of silicon; 9.0% to 30% by weight of manganese; less than or equal to 8% by weight of chromium; less than or equal to 6% by weight of nickel; less than or equal to 6% by weight of molybdenum; less than or equal to 5% by weight of tungsten; less than or equal to 4% by weight of copper; less than or equal to 2% by weight of niobium; less than or equal to 2% by weight of vanadium; less than or equal to 2% by weight of titanium; less than or equal to 0.4% by weight of nitrogen; less than or equal to 1% by weight of boron; at least one of the following: (i) less than or equal to 0.3% by weight of sulfur, (ii) less than or equal to 0.03% by weight of phosphorus, or (iii) combinations thereof; and the balance being iron.

[0125] In any aspect or embodiment described herein, chromium is 2 to 6% by weight; nickel is 0 to 5% by weight; molybdenum is 0.5 to 3% by weight; tungsten is 0.1 to 2% by weight; copper is less than 2% by weight; niobium is less than 1% by weight; vanadium is less than 1% by weight; titanium is less than 1% by weight; nitrogen is 0.01 to 0.3% by weight; and / or boron is 0.01 to 0.4% by weight.

[0126] In any aspect or embodiment described herein, carbon is 0.45 to 0.7 wt%; silicon is 0.2 to 1.5 wt%; and / or manganese is 12 to 20 wt%.

[0127] According to another aspect, this disclosure provides a metal-cored welding wire for submerged arc welding, the welding wire comprising a steel sheath and a powder-containing core, said powder being: 0.3 wt% to 1.2 wt% carbon; 0.1 wt% to 3.0 wt% silicon; 9.0 wt% to 30 wt% manganese; less than 8 wt% chromium; less than 6 wt% nickel; less than 6 wt% molybdenum; less than 5 wt% tungsten; less than 4 wt% copper; less than 2 wt% niobium; less than 2 wt% vanadium; less than 2 wt% titanium; less than 0.4 wt% nitrogen; less than 1 wt% boron; at least one of the following: (i) less than 0.3 wt% sulfur, (ii) less than 0.03 wt% phosphorus, or (iii) combinations thereof; and the balance being iron.

[0128] In any aspect or embodiment described herein, the steel is carbon steel or high-manganese steel.

[0129] In any aspect or embodiment described herein, the steel sheath has a welded longitudinal seam.

[0130] In any aspect or embodiment described herein, the surface of the steel sheath is coated with copper.

[0131] According to another aspect, this disclosure provides a method for welding high-manganese steel, the method comprising: supplying at least one high-manganese steel part; supplying a metal-core welding wire of this disclosure; immersing the at least one high-manganese steel part in slag and an arc stabilizer; and applying an electric current to the metal-core welding wire to produce a liquid alloy steel composition on the at least one high-manganese steel part.

[0132] In any aspect or embodiment described herein, the slag comprises: 22-24% Al2O3; 10-12% SiO2; 6-8% MnO; 22.5-24.5% CAF2; 10.5-12.5% ​​MgO; 11.5-13.5% CO2; 2.5-4.5% CaO; 0.5-2.5% Na2O; 1.0-3.0% TiO2; 0.5-1.6% ZrO2; 0.3-1.3% K2O; 0.2-1.2% Fe; 0.2-2.2% Mn; and / or 0.1-1.0% Si.

[0133] In any aspect or embodiment described herein, the at least one high-manganese steel component is at least two high-manganese steel components, and applying current to the metal-core welding wire produces a liquid steel composition at the joint between the at least two high-manganese steel components.

[0134] In any aspect or embodiment described herein, the method further comprises cooling the liquid alloy steel composition to form an alloy steel composition that joins the at least two high-manganese steel pieces.

[0135] In any aspect or embodiment described herein, the slag and arc stabilizer comprise at least one of TiO2, SiO2, ZrO2, Al2O3, Na2O, K2O, metal fluoride, or combinations thereof.

[0136] In any aspect or embodiment described herein, the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

[0137] In any aspect or embodiment described herein, the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

[0138] In any aspect or embodiment described herein, the slag comprises: 23.1% Al2O3; 11.2% SiO2; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; and / or 0.5% Si.

[0139] Although this disclosure has been described in principle in connection with steel compositions used in components for use in the oil, gas, and / or petrochemical industries / systems / applications, such description is for disclosure purposes only and is not intended to limit the disclosure. Rather, it is to be appreciated that the disclosed steel compositions can be used in a wide variety of applications, systems, operations, and / or industries.

[0140] Although the systems and methods of this disclosure have been described with reference to exemplary embodiments thereof, this disclosure is not limited to such exemplary embodiments and / or implementation processes. Rather, the systems and methods of this disclosure are readily apparent to those skilled in the art from this disclosure in many implementations and applications. This disclosure expressly includes such modifications, enhancements, and / or variations of the disclosed embodiments. Because many changes can be made to the foregoing construction and many widely different embodiments of this disclosure can be made without departing from its scope, all matters contained in the drawings and specification are intended to be interpreted as exemplary and not as limiting. Further modifications, variations, and substitutions are intended within the scope of the foregoing disclosure. Therefore, it is appropriate that the appended claims be interpreted broadly and in a manner consistent with the scope of this disclosure.

Claims

1. A welding composition comprising: 0.3% to 1.2% carbon by weight; 0.1% to 3.0% by weight of silicon; 9.0% to 30% manganese by weight; Chromium in an amount less than or equal to 8% by weight; Nickel in amounts less than or equal to 6% by weight; Molybdenum in amounts ranging from 0.2% to 6% by weight; Tungsten in amounts less than or equal to 5% by weight; Copper in amounts less than or equal to 4% by weight; Niobium in amounts less than or equal to 2% by weight; Vanadium in an amount less than or equal to 2% by weight; Titanium in amounts of 0.2% to 2% by weight; Nitrogen in amounts less than or equal to 0.4% by weight; Boron in amounts ranging from 0.2% to 1% by weight; At least one of the following: i. Sulfur in an amount less than or equal to 0.3% by weight; ii. Phosphorus in an amount less than or equal to 0.03% by weight; or iii. Their combination; and The remainder is iron.

2. The composition of claim 1, wherein at least one of the following is true: Chromium content is 2 to 6% by weight. Nickel content is 0 to 5% by weight. Molybdenum content is 0.5% to 3% by weight. Tungsten is 0.1 to 2% by weight. Copper is present in amounts less than 2% by weight; Niobium is present in amounts less than 1% by weight; Vanadium is present in amounts less than 1% by weight; Titanium is present in amounts less than 1% by weight; Nitrogen content is 0.01 to 0.3% by weight. Boron is 0.2% to 0.4% by weight; or Its combination.

3. The welding composition of claim 1 or 2, wherein at least one of the following is present: carbon from 0.45 to 0.7 wt%; silicon from 0.2 to 1.5 wt%; manganese from 12 to 20 wt%; or a combination thereof.

4. A metal-cored welding wire for submerged arc welding, the welding wire comprising a steel sheath and a powder-containing core, wherein the powder is: 0.3% to 1.2% carbon by weight; 0.1% to 3.0% by weight of silicon; 9.0% to 30% manganese by weight; Less than 8% by weight of chromium; Less than 6% by weight of nickel; Molybdenum in amounts ranging from 0.2% to 6% by weight; Less than 5% by weight of tungsten; Copper in amounts less than 4% by weight; Less than 2% by weight of niobium; Vanadium in amounts less than 2% by weight; Titanium in amounts of 0.2% to 2% by weight; Nitrogen in amounts less than 0.4% by weight; Boron in amounts ranging from 0.2% to 1% by weight; At least one of the following: i. Sulfur content less than 0.3% by weight; ii. Phosphorus less than 0.03% by weight; or iii. Their combination; and The remainder is iron.

5. The metal-cored welding wire of claim 4, wherein the steel is carbon steel or high-manganese steel.

6. The metal-core welding wire of claim 4 or 5, wherein the steel sheath has a welded longitudinal seam.

7. The metal core welding wire of claim 4 or 5, wherein the surface of the steel sheath is coated with copper.

8. The metal core welding wire of claim 6, wherein the surface of the steel sheath is coated with copper.

9. A method for welding high-manganese steel, the method comprising: supplying at least one high-manganese steel part; supplying a metal-cored welding wire according to any one of claims 4-8; immersing the at least one high-manganese steel part in slag and an arc stabilizer; and applying an electric current to the metal-cored welding wire to form a liquid alloy steel composition on the at least one high-manganese steel part.

10. The method of claim 9, wherein the slag comprises at least one of the following: 22-24% Al2O3; 10-12% SiO2; 6-8% MnO; 22.5-24.5% CAF2; 10.5-12.5% ​​MgO; 11.5-13.5% CO2; 2.5-4.5% CaO; 0.5-2.5% Na2O; 1.0-3.0% TiO2; 0.5-1.6% ZrO2; 0.3-1.3% K2O; 0.2-1.2% Fe; 0.2-2.2% Mn; 0.1-1.0% Si; or combinations thereof.

11. The method of claim 9 or 10, wherein the at least one high-manganese steel member is at least two high-manganese steel members, and an electric current is applied to the metal core welding wire to generate a liquid steel composition at the joint between the at least two high-manganese steel members.

12. The method of claim 9 or 10, further comprising cooling the liquid alloy steel composition to form an alloy steel composition for joining the at least two high-manganese steel pieces.

13. The method of claim 11, further comprising cooling the liquid alloy steel composition to form an alloy steel composition for joining the at least two high-manganese steel pieces.

14. The method of claim 9, 10, or 13, wherein the slag and arc stabilizer comprise at least one of TiO2, SiO2, ZrO2, Al2O3, Na2O, K2O, a metal fluoride, or a combination thereof.

15. The method of claim 11, wherein the slag and arc stabilizer comprise at least one of TiO2, SiO2, ZrO2, Al2O3, Na2O, K2O, metal fluoride, or a combination thereof.

16. The method of claim 12, wherein the slag and arc stabilizer comprise at least one of TiO2, SiO2, ZrO2, Al2O3, Na2O, K2O, metal fluoride, or a combination thereof.

17. The method of any one of claims 9-10 or 13 or 15-16, wherein the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

18. The method of claim 11, wherein the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

19. The method of claim 12, wherein the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

20. The method of claim 14, wherein the metal fluoride is selected from: CaF2, NaF2, MgF2, BaF2 and K2ZrF6.

21. The method of any one of claims 9-10, or claim 13, or any one of claims 15-16, or any one of claims 18-20, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

22. The method of claim 11, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

23. The method of claim 12, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

24. The method of claim 14, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

25. The method of claim 17, wherein the current applied at a welding speed of 510 to 650 mm / min is 530 to 630 A.

26. The method of any one of claims 9-10, or claim 13, or any one of claims 15-16, or any one of claims 18-20, or any one of claims 22-25, wherein the slag comprises at least one of the following: 23.1% Al2O3; 11.2% SiO2; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

27. The method of claim 11, wherein the slag comprises at least one of the following: 23.1% Al₂O₃; 11.2% SiO₂; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

28. The method of claim 12, wherein the slag comprises at least one of the following: 23.1% Al₂O₃; 11.2% SiO₂; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

29. The method of claim 14, wherein the slag comprises at least one of the following: 23.1% Al₂O₃; 11.2% SiO₂; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

30. The method of claim 17, wherein the slag comprises at least one of the following: 23.1% Al₂O₃; 11.2% SiO₂; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

31. The method of claim 21, wherein the slag comprises at least one of the following: 23.1% Al2O3; 11.2% SiO2; 7.1% MnO; 23.4% CAF2; 11.6% MgO; 12.4% CO2; 3.5% CaO; 1.3% Na2O; 2.1% TiO2; 1.1% ZrO2; 0.8% K2O; 0.7% Fe; 1.2% Mn; 0.5% Si; or combinations thereof.

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