High alloy welding wire with copper-based coating
Patent Information
- Application Number
- JP2024521230
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-10-12
- Filing Date
- 2022-10-13
- Publication Date
- 2025-10-22
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Abstract
Description
[Technical field]
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 256,290, entitled "HIGH ALLOY WELDING WIRE WITH COPPER BASED COATING," filed October 15, 2021, and U.S. Nonprovisional Patent Application No. 18 / 045,934, entitled "HIGH ALLOY WELDING WIRE WITH COPPER BASED COATING," filed October 12, 2022, which applications are incorporated by reference herein in their entireties.
[0002] FIELD OF THE DISCLOSURE The present disclosure relates generally to consumable welding electrodes and welding processes utilizing same. [Background technology]
[0003] Welding is a widespread process in industrial applications for a variety of applications. Depending on the process, a welding wire can act as a consumable electrode that functions as a metal source for forming a weld on a workpiece as well as a mechanism for providing flux and other welding performance additives. For example, in metal arc welding, an electric arc is created when a voltage is applied between the welding wire (first electrode) and the workpiece (second electrode). When a current is generated, an arc is created between the electrodes, melting the tip of the welding wire and producing a weld bead of molten metal at the point of contact on the workpiece. Generally, the welding wire is continuously fed into the welding system to provide a stream of molten metal that creates a weld on the workpiece.
[0004] The chemical composition, physical state, and presence of layers and coatings on the welding wire can all affect numerous welding properties. The chemical metal composition of the welding wire can change the bead and weld quality, both in appearance and in mechanical properties, including yield strength, ductility, and fracture toughness. Furthermore, the structural properties of the welding wire can also affect other components of the welding system. The feed system and contact tips, for example, experience friction and electrical resistance that are dependent on the properties of the welding wire, which can affect the mechanical wear and overall useful life of these system components. Summary of the Invention [Means for solving the problem]
[0005] In one aspect, a welding wire disclosed herein may include a high alloy metal core comprising greater than about 10.5 weight percent of the high alloy metal core of an element selected from aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloy, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, vanadium, or combinations thereof, and a layer surrounding the high alloy metal core, the layer comprising copper or a copper alloy.
[0006] In another aspect, a welding method disclosed herein may include applying a current sufficient to convert a welding wire to a molten state and produce a molten welding material, the welding wire comprising a high alloy metal core, the high alloy metal core including greater than about 10.5 weight percent of an element selected from aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloy, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, vanadium, or combinations thereof, and a layer surrounding the high alloy metal core, the layer including copper or a copper alloy; and depositing the molten welding material on a workpiece.
[0007] Certain embodiments of the invention may take physical form in certain parts and arrangements of parts, preferred embodiments thereof are described in detail herein and illustrated in the accompanying drawings from which this specification relates. [Brief description of the drawings]
[0008] [Figure 1] FIG. 1 is an embodiment of a coated wire according to one embodiment. [Diagram 2] FIG. 2 is a flow diagram of a non-limiting embodiment of a welding method. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0009] The present disclosure generally relates to consumable welding electrodes and welding processes utilizing the same. The welding wire compositions disclosed herein exhibit reduced contact tip wear and improved electrical properties. Specifically, the welding wire compositions disclosed herein include a high alloy core coated with a layer of copper or copper alloy. The copper or copper alloy layer may also exhibit improved compatibility with the copper contact tip while forming a conductive layer that also reduces mechanical and electrically induced wear.
[0010] In arc welding applications, high alloy welding wire may have many advantages, including good appearance, corrosion resistance, tarnish resistance, and oxidation resistance at high temperatures. However, high alloy welding wire often exhibits higher tensile strength and surface hardness that may increase wear on the wire-feeding components of the welding system, which are often composed of softer metals and alloys. Additionally, the conductivity difference between the high alloy wire and the contact tip (often constructed from copper) also contributes to arc formation and burnback that may result in clogging and feeding problems. Despite these drawbacks, high alloy welding wire is often used in uncoated form or with a non-metallic coating, such as silicone, to produce welds that are naturally corrosion resistant and have excellent weld appearance and strength.
[0011] Conductive metal outer surface layers and coatings have been employed for many welding wires, but may have potential disadvantages. Copper coatings, for example, have been used to coat low-alloy solid metal and flux-cored welding wires to improve corrosion resistance, increase conductivity, reduce contact tip deterioration, and lubricate the wire during drawing and feeding through the welding equipment. However, the use of copper coatings may also entail a number of disadvantages. Copper metal is soft and has a tendency to produce flakes of copper metal during forced feeding of the wire through the welding system, including passing through the liner, torch, and contact tip. During the passage of each of these components, the copper flakes can cause a number of mechanical problems, including the formation of agglomerates that form plugs or electrical contact points that can cause hot spots. Even worse, the copper flakes can induce a form of liquid metal embrittlement, or "copper cracking," which reduces the strength of the weld. During welding, the copper flakes can be melted by the molten slag and displaced into the weld bead. As the bead metal cools, the copper remains molten and flows into the grain boundaries of the solidified metal, where the soft copper metal forms weak spots that weaken the weld and / or the workpiece metal.
[0012] Contrary to these findings in the art, the welding wire composition disclosed herein utilizes a high alloy metal core surrounded by a layer of copper or copper alloy to form a consumable electrode. The low resistivity of the copper-containing layer allows for the transfer of current to the contact tip as the wire is passed, which reduces heat loss in the torch and minimizes or eliminates arc formation between the wire and the contact tip. Because copper is softer compared to the high alloy metal core of the welding wire, the copper-containing layer also reduces abrasion and mechanical wear on the feed components of the welding system, which are often constructed from similar copper materials. Unexpectedly, the welding wire composition disclosed herein exhibits similar or better performance than comparable uncoated high alloy wires, improving the useful life of the contact tip and maintaining weld strength without copper cracking.
[0013] The welding wire composition disclosed herein generally includes a high alloy metal core with a surrounding copper-containing layer. As used herein, the term "high alloy metal" can refer to an alloy including one or more metals and at least 8 wt. % (e.g., greater than about 10.5%) of alloying elements such as aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloy, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, and / or vanadium. The high alloy metal core can include a high alloy metal having sufficient conductivity for the current and conditions applied in the selected welding process. In some embodiments, the high alloy core can include a high alloy steel containing iron and more than about 10.5 wt. % of any one or more of aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloy, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, and / or vanadium. High alloy metals may include, for example, stainless steels, maraging steels, Cr-Mo alloy steels, nickel alloys such as 276, 625, 718 nickel alloys, combinations thereof, and / or the like. Welding wire compositions incorporating high alloy metal cores may also include blends of any of the above alloys, including multi-layer and duplex stainless steels.
[0014] In some embodiments, the high alloy core may include a stainless steel composition having, for example, chromium in a weight percent (wt%) of the high alloy metal core of about 12 wt% to about 18 wt%. Suitable stainless steels may include one or more common grades (e.g., 200, 300, 400, etc.) of stainless steel, including martensitic, austenitic, or ferritic stainless steels. In some embodiments, the high alloy metal core may be a 300 grade austenitic stainless steel, such as 302, 303, 304, 316, 310, or 321 grade stainless steel.
[0015] The inclusion of a copper-containing layer covering the high alloy metal core may also have advantages during production of the welding wire. For example, the use of a copper or copper alloy coating may act as a lubricant during wire draw, minimizing or eliminating the need for additional additives or coatings. In some cases, the presence of a copper-containing layer may allow direct drawing from a larger stock to produce the welding wire composition to a suitable working diameter and at increased speeds compared to uncoated stainless steel wire. In some embodiments, the welding wire composition may include multiple copper-containing layers. For example, multiple copper-containing layers may surround the high alloy metal core.
[0016] The one or more copper-containing layers may include copper and copper alloys that are coated and bonded to the high alloy metal core by any suitable process. In some embodiments, additional coating layers, such as nickel, may be introduced during fabrication of the copper-containing layers, which may improve compatibility with the high alloy metal core. Suitable copper alloys include alloys of copper and one or more metals selected from nickel, zinc, chromium, cadmium, and / or tin. The copper alloys disclosed herein may include copper in a weight percent (wt%) of the copper alloy of up to about 90 wt%, up to about 95 wt%, up to about 99 wt%, or up to about 99.9 wt%. In some embodiments, the copper alloys may include copper in a content by weight percent of the alloy ranging from about 60 wt% to about 95 wt%, or from about 60 wt% to about 99.9 wt%. In some embodiments where the welding wire composition includes multiple copper-containing layers, one or more of the copper-containing layers can have alternate material compositions (e.g., the copper content in a first copper-containing layer of the welding wire composition can be greater than the copper content in a second copper-containing layer).
[0017] The selection of copper or copper alloy as the envelope layer may depend on a number of factors, including the type of welding process and the metal composition of the workpiece. In some cases, depending on the nature of the high alloy metal in the core, the surface tension of the copper-containing layer may be adjusted, for example, by modifying the copper content of the alloy to minimize copper flow into the grain boundaries of the weld metal. The thickness of the copper-containing layer may also vary depending on the particular application. The welding wire composition may include a high alloy metal core having a copper-containing layer disposed thereon, the copper-containing layer having a thickness of greater than about 0.01 μm, greater than about 0.1 μm, greater than about 1 μm, and the like. In some embodiments, the copper-containing layer may have a thickness ranging from about 0.1 μm to about 100 μm.
[0018] The copper-containing layer may be present in a weight percent (wt%) of the welding wire ranging from about 0.005 wt% to about 3 wt%, from about 0.005 wt% to about 2 wt%, or from about 0.005 wt% to about 1 wt%. The copper-containing layer may comprise up to about 5% of the cross-sectional area of the welding wire, including up to about 0.01% to about 5% of the cross-sectional area of the welding wire in some embodiments.
[0019] Although numerous solid core welding wire embodiments are disclosed herein, it is also contemplated that the components of the welding wire composition may also be adapted to produce a flux cored welding wire having a flux material surrounded by a high alloy metal sheath having a copper coating layer disposed thereon.
[0020] The welding wire compositions disclosed herein may be drawn or otherwise fabricated to any suitable diameter (e.g., 0-30 gauge or larger) for a selected welding process. In general, the welding methods disclosed herein may include applying a current sufficient to convert the welding wire composition to a molten state, the welding wire including a high alloy metal core and a copper-containing layer surrounding the high alloy metal core, and depositing a molten droplet onto the workpiece. The welding process is not considered to be specifically limited and may include gas-metal arc welding processes such as submerged-arc welding (SAW), gas tungsten arc welding (GTAW), gas metal arc welding (GMAW), shielded metal arc welding (SMAW), flux-cored techniques such as flux-cored arc welding (FCAW), and combinations thereof.
[0021] With reference to Figure 1, one embodiment of a coated welding wire 100 is shown including a core 102 and a layer 104 surrounding the core. For clarity, portions of layer 104 have been removed from the coated welding wire 100 shown in Figure 1 to illustrate the inner core 102 coated along the length of the wire 100 with layer 104. In embodiments, the core 102 is a high alloy metal core and the layer 104 comprises copper or a copper alloy. With reference to Figure 2, in one embodiment, a welding method 200 is shown. Step 202 includes applying a sufficient current to convert the welding wire to a molten state and produce a molten welding material, the welding wire (e.g., coated welding wire 100) comprising a high alloy metal core (e.g., core 102) comprising greater than about 10.5 wt. % of the high alloy metal core selected from aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloy, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, vanadium, or combinations thereof, and a layer surrounding the high alloy metal core comprising copper or a copper alloy. Step 204 includes depositing the molten welding material onto the workpiece.
[0022] To facilitate a better understanding of the embodiments of the present invention, the following examples of preferred or representative features are given and should not be construed in any way as limiting or defining the scope of the embodiments.
[0023] The following non-limiting examples are provided to further illustrate the embodiments of the present invention. Those skilled in the art should understand that the techniques disclosed in the following examples represent approaches that the inventors have found to work well in implementing the embodiments of the present invention, and therefore may be considered to constitute examples of the manner of implementation. However, those skilled in the art should understand in view of the embodiments of the present invention that many changes can be made in the specific embodiments disclosed and still obtain the same or similar results without departing from the spirit and scope of the embodiments. EXAMPLES
[0024] Example 1: Welding performance of Cu-coated 302 grade stainless steel In this example, welds were produced using copper coated stainless steel solid wire (Cu coated 302) and comparative uncoated 316LSi grade stainless steel (uncoated 316LSi). Both wire samples exhibited a diameter of 0.045". Testing was performed on an automated arc welding apparatus configured to apply test welds at a controlled contact tip to work distance (CTWD). Test welds were made on 24" diameter pipe with a continuous weld to minimize measurement interference from starts and stops. Test welds were run until failure occurred, typically indicated by spatter clogging the nozzle and contacting the work piece. Table 1 summarizes the welding conditions and settings, where welds were made using constant voltage (CV) and pulses.
[0025] [Table 1]
[0026] The weld appearance for the Cu-coated 302 samples was analyzed alongside the uncoated 316LSi for all conditions investigated. A range of shielding gas compositions were also tested. The results and conditions for the tests are summarized in Table 2, where a rating of 4 is equivalent to the uncoated 302 results. In general, the bead appearance of the Cu-coated 302 was rougher in appearance with some superficial pitting, but otherwise did not affect the weld strength.
[0027] [Table 2]
[0028] Example 2 - Contact Tip Wear Analysis In this example, contact tip wear rates for uncoated 316LSi and Cu-coated 302 were studied using an automated arc welding apparatus as described above in Example 1. Amperage and voltage measurements were recorded for each sample approximately 415-417 times per minute during testing to monitor effective CTWD. For all weld samples and conditions studied, there was little difference in amperage loss between samples. Specifically, the uncoated 316LSi sample exhibited a drop of 7.5 amps after one hour, while the Cu-coated 302 sample exhibited 9.9 amps after one hour.
[0029] After the weld run, the wear of the contact tip was quantified by measuring the change in the inside diameter of the contact tip center hole. Although the change in amperage was small between the bare 316LSi and Cu-coated 302 welding wire, the bare 316LSi exhibited significant mechanical wear on the contact tip as evidenced by the inside diameter. The results are summarized in Table 3.
[0030] [Table 3]
[0031] As shown in Table 3, the rate of increase in hole area over time was much smaller for the copper coated wire samples. The rate of diameter increase for the copper coated samples appears to be 2-3 times smaller than uncoated 316LSi. The results indicate that the copper coated stainless steel weld wire compositions disclosed herein can be used to improve contact tip service life compared to uncoated stainless steels without appreciable changes in weld performance or weld strength.
[0032] Thus, the disclosed system and method are well adapted to attain the objects and advantages mentioned above, as well as those inherent therein. The particular aspects disclosed herein are merely illustrative, as the invention may be modified and embodied in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. Furthermore, no limitations are intended to the details of construction or design shown herein, other than as described in the appended claims. It is therefore apparent that the particular exemplary aspects disclosed above may be altered, combined or modified, and all such variations are deemed to be within the scope and spirit of the present invention. The terms in the claims have their plain and ordinary meaning unless otherwise expressly and unambiguously defined by the patentee.
[0033] Unless otherwise indicated, all numbers expressing quantities of ingredients, reaction conditions, and so forth used in the specification and related claims are to be understood as being modified in all instances by the term "about." Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by embodiments of the present invention.
[0034] In some embodiments, the terms "a," "an," and "the," and similar references, in the context of describing embodiments of the present disclosure (particularly in the context of the appended claims), may be construed to encompass both the singular and the plural, unless expressly indicated otherwise. In some embodiments, the term "or," as used herein, including in the claims, is used to mean "and / or," unless expressly indicated to refer to alternatives only or the alternatives are not mutually exclusive.
[0035] The terms "comprise," "have," and "include" are open-ended linking verbs. Any form or tense of one or more of these verbs, such as "comprises," "comprising," "has," "having," "includes," and "including," are also open-ended. For example, any method that "comprises," "has," or "includes" one or more steps is not limited to having only those one or more steps, but can also include other unrecited steps. Similarly, any composition or device that "comprises," "has," or "includes" one or more features is not limited to having only those one or more embodiments, but can also include other unrecited embodiments. Although systems, compositions, and methods may be described herein in terms of "comprising" various components or steps, methods may also "consist essentially of" or "consist of" various components and steps.
[0036] All methods described herein may be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. The use of any and all examples or exemplary language (e.g., "such as") provided herein with respect to some embodiments is merely intended to facilitate easier understanding of the invention and does not impose limitations on the scope of the invention as otherwise claimed. No language in the specification should be construed as indicating that any non-claimed element is essential to the practice of the invention.
[0037] Groupings of alternative elements or embodiments disclosed herein should not be construed as limitations. Each group member may be referenced and claimed individually or in any combination with other members of the group, or with other elements found herein. One or more members of a group may be included in or deleted from a group for reasons of convenience or patentability. When any such inclusion or deletion is made, the specification is deemed to now include the group as modified and therefore to satisfy the written description of all Markush groups used in the appended claims.
[0038] Although the embodiments have been described in detail, it will be apparent that modifications, variations, and equivalents are possible without departing from the scope of the embodiments defined in the appended claims. Furthermore, it should be understood that all examples in the embodiments are provided as non-limiting examples.
Claims
1. a high alloy metal core comprising greater than about 10.5 weight percent of said high alloy metal core of an element selected from aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloys, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, vanadium, or combinations thereof; a layer surrounding the high alloy metal core, the layer comprising copper or a copper alloy; and A welding wire comprising:
2. 10. The welding wire of claim 1, wherein the layer comprises the copper alloy, the copper alloy comprising copper in a weight percent (wt%) of up to about 99.9 wt% of the copper alloy.
3. 3. The welding wire of claim 2, wherein the copper alloy comprises a balance of at least one metal selected from cadmium, chromium, nickel, tin, zinc, or combinations thereof.
4. 4. The welding wire of claim 1, wherein the layer comprises the copper alloy, the copper alloy comprising copper in a weight percent (wt%) of the copper alloy ranging from about 60 wt% to about 99.9 wt%.
5. The welding wire of any one of claims 1 to 3, wherein the high alloy metal core comprises chromium in a weight percent (wt%) of the high alloy metal core ranging from about 12 wt% to about 18 wt%.
6. The welding wire according to any one of claims 1 to 3, wherein the high alloy metal core comprises austenitic stainless steel.
7. The welding wire according to any one of claims 1 to 3, wherein the high alloy metal core comprises a dual phase steel.
8. The welding wire according to any one of claims 1 to 3, wherein the layer has a thickness in the range of about 0.1 μm to about 100 μm.
9. 4. The welding wire of claim 1, wherein the layer is present in a weight percent (wt%) of the welding wire ranging from about 0.005 wt% to about 3 wt%.
10. The welding wire of any one of claims 1 to 3, wherein the layer comprises about 0.005% to about 5% of the cross-sectional area of the welding wire.
11. A weld deposit produced by the welding wire according to any one of claims 1 to 3.
12. A welding method comprising: applying a current sufficient to convert the welding wire to a molten state and produce a molten welding material, wherein the welding wire is a high alloy metal core comprising greater than about 10.5 weight percent of said high alloy metal core of an element selected from aluminum, bismuth, chromium, molybdenum, chromium / molybdenum alloys, cobalt, copper, manganese, nickel, silicon, titanium, tungsten, vanadium, or combinations thereof; a layer surrounding the high alloy metal core, the layer comprising copper or a copper alloy; and applying depositing the molten welding material onto a workpiece; A welding method comprising:
13. The welding method of claim 12 , wherein the welding method comprises at least one of submerged arc welding (SAW), tungsten arc welding (GTAW), gas metal arc welding (GMAW), or a combination thereof.
14. 14. The welding method of claim 12 or 13, wherein the layer comprises the copper alloy, the copper alloy comprising copper in a weight percent (wt%) of up to about 99.9 wt% of the copper alloy.
15. 15. The welding method of claim 14, wherein the balance of the copper alloy comprises at least one metal selected from cadmium, chromium, nickel, tin, zinc, or combinations thereof.
16. The welding method of claim 12 or 13, wherein the layer comprises about 0.005% to about 5% of the cross-sectional area of the welding wire.
17. The welding method of claim 12 or 13, wherein the high alloy metal core comprises chromium in a weight percent (wt%) of the high alloy metal core ranging from about 12 wt% to about 18 wt%.
18. 14. The welding method of claim 12 or 13, wherein the layer is present in a weight percent (wt%) of the welding wire ranging from about 0.005 wt% to about 3 wt%.
19. The welding method of claim 12 or 13, wherein the high alloy metal core comprises an austenitic stainless steel.
20. The welding method of claim 12 or 13, wherein the layer has a thickness ranging from about 0.1 μm to about 100 μm.