Welding wire steel and welding wire for welding ultralow-temperature high-manganese steel, and preparation method and welding method of welding wire steel and welding wire

Abstract

The invention provides welding wire steel for welding ultralow-temperature high manganese steel, a welding wire, a preparation method of the welding wire and a welding method. The welding wire steel for welding the ultralow-temperature high manganese steel comprises the following components in percentage by mass: 0.05 to 0.1 percent of C; 0.5 to 0.6 percent of Si; 24% to 25% of Mn; p is less than or equal to 0.01%; s is less than or equal to 0.01%; 0.05% to 0.1% of Al; 0.12 to 0.2 percent of Ni; 0.02% to 0.06% of N; 0.08% to 0.15% of Ti; v, 0.08% to 0.15%; 0.08% to 0.15% of Nb; 0.05% to 0.1% of Mo; and the balance of Fe and inevitable impurities. The welding wire composition design is optimized, only a small amount of Ni element is added, W and other high-melting-point elements are not added, and a small amount of C, N, Ti, V, Nb and other alloy elements are transited to a welding seam through the welding wire, so that nitride, carbide and other pinning grain boundaries are formed in the welding seam at the high temperature, austenite grain growth is effectively prevented, the austenite grain size is reduced, and the low-temperature impact toughness of the welding seam is improved; in addition, a small amount of Si element is transited to the welding seam through the welding wire, molten pool fluidity is improved, slag floating is promoted, and slag inclusion of the welding seam is avoided.

Description

Technical Field

[0001] The present application relates to the technical field of steel materials, and in particular to a welding wire steel, welding wire and a preparation method thereof, and a welding method for ultra-low temperature high manganese steel welding. Background Art

[0002] Low temperature steel has good toughness and good weldability. It is the main raw material for many devices such as LNG cryogenic storage tanks and is widely used in the fields of energy, chemical industry and national defense engineering. It has always been believed that Ni-containing low temperature steel represented by 9Ni is expensive due to its high alloy content; moreover, 9Ni steel is easily magnetized and prone to magnetic blow during arc welding, which seriously affects the stability of the welding process and thus affects the welding quality; compared with 9Ni, ultra-low temperature high manganese steel Mn24 has certain advantages in terms of cost and performance; Mn24 is made by adding more than 20% of Mn elements to the steel, so that the steel obtains a stable austenite structure at room temperature, and at the same time, certain C and N elements are added to the steel to stabilize the austenite and inhibit phase transformation, and has excellent low temperature toughness; moreover, the price ratio of Ni to Mn has been above 5.5:1. Replacing 9Ni with ultra-low temperature high manganese steel can significantly reduce the manufacturing cost of LNG cryogenic storage tanks and has great application prospects.

[0003] The chemical composition of ultra-low temperature high manganese steel Mn24 is as follows: C 0.4-0.5, Si 0.3-0.5, Mn 23-25, P≤0.01, S≤0.005, Cu 0.2-0.3, Ni 0.1-0.3, Cr 3.5-4.5, Nb 0.01-0.03, V 0.05-0.3, Ti 0.005-0.05, Mo≤0.05, N≤0.05; mechanical properties are as follows: yield strength ≥440MPa, tensile strength ≥840MPa, elongation ≥45%, -196℃ impact energy ≥80J; organization: austenite. Due to the late application of ultra-low temperature high manganese steel Mn24, welding materials and welding processes are not mature. As for the existing ultra-low temperature high manganese steel Mn24 welding materials, in addition to adding a high content of Mn elements, relatively high contents of Ni elements and W elements are also added. The amount of alloy added is large and the alloy cost is high. In addition, there are also problems such as large work hardening, difficulty in welding wire processing, increased welding smoke due to copper plating of welding wire, and increased health hazards to welding operators. Summary of the invention

[0004] The embodiments of the present application provide a welding wire for ultra-low temperature high manganese steel welding, a preparation method thereof, and a welding method, which aim to reduce the alloy cost of welding materials, reduce the burnout of alloy elements during the welding process, reduce welding smoke, and improve the welding working environment. At the same time, the ultra-low temperature impact toughness of the weld is improved, welding defects are reduced, and the welding quality is improved.

[0005] In the first aspect, the embodiment of the present application provides a welding wire steel for ultra-low temperature high manganese steel welding, comprising the following components in percentage by mass: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24-25%; P≤0.01%; S≤0.01%; Al, 0.05-0.1%; Ni, 0.12-0.2%; N, 0.02-0.06%; Ti, 0.08%-0.15%; V, 0.08%-0.15%; Nb, 0.08%-0.15%; Mo, 0.05%-0.1%; the balance is Fe and unavoidable impurities.

[0006] According to the embodiment of the first aspect of the present application, the welding wire steel used for ultra-low temperature high manganese steel welding satisfies at least one of the following characteristics: (1) tensile strength ≥ 800Mpa; (2) yield strength ≥ 435Mpa; (3) -196℃ impact energy ≥ 68J.

[0007] In a second aspect, an embodiment of the present application provides a welding wire for ultra-low temperature high manganese steel welding, comprising the following components in percentage by mass: C, 0.05% to 0.1%; Si, 0.5% to 0.6%; Mn, 24% to 25%; P≤0.01%; S≤0.01%; Al, 0.05% to 0.1%; Ni, 0.12% to 0.2%; N, 0.02% to 0.06%; Ti, 0.08% to 0.15%; V, 0.08% to 0.15%; Nb, 0.08% to 0.15%; Mo, 0.05% to 0.1%; the remainder is Fe and unavoidable impurities.

[0008] In a third aspect, an embodiment of the present application provides a method for preparing a welding wire for ultra-low temperature high manganese steel welding, comprising the following steps:

[0009] The molten steel is subjected to converter smelting, refining, continuous casting and rolling to obtain welding wire steel for ultra-low temperature high manganese steel welding, wherein the welding wire steel comprises the following components by mass percentage: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24%-25%; P≤0.01%; S≤0.01%; Al, 0.05%-0.1%; Ni, 0.12-0.2%; N, 0.02-0.06%; Ti, 0.08%-0.15%; V, 0.08%-0.15%; Nb, 0.08%-0.15%; Mo, 0.05%-0.1%; the balance is Fe and unavoidable impurities;

[0010] The welding wire steel for ultra-low temperature high manganese steel welding is rolled into wire rods and annealed;

[0011] The wire rod is drawn and polished to obtain welding wire for ultra-low temperature high manganese steel welding.

[0012] In a fourth aspect, an embodiment of the present application provides a method for welding ultra-low temperature high manganese steel, comprising the following steps:

[0013] A V-shaped groove is formed on ultra-low temperature high manganese steel to be welded of equal thickness, wherein the angle α of the V-shaped groove ranges from 50° to 70°;

[0014] The ultra-low temperature high manganese steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the ultra-low temperature high manganese steel to be welded is in the range of 1 to 3 mm;

[0015] The end of the aforementioned welding wire for welding ultra-low temperature high manganese steel is placed close to the part to be welded of the ultra-low temperature high manganese steel. Under the action of the welding power supply, an arc is formed between the end of the welding wire for welding ultra-low temperature high manganese steel and the surface to be welded of the ultra-low temperature high manganese steel to achieve welding.

[0016] According to an embodiment of the fourth aspect of the present application, the diameter of the welding wire used for welding ultra-low temperature high manganese steel is 1.4 mm.

[0017] According to an embodiment of the fourth aspect of the present application, during the welding process, the welding current of the welding power source is in the range of 120 to 180A, and the welding voltage is in the range of 13 to 24V.

[0018] According to an embodiment of the fourth aspect of the present application, during the welding process, the shielding gas is a 95% Ar + 5% CO2 mixed gas.

[0019] According to an embodiment of the fourth aspect of the present application, when the thickness of the ultra-low temperature high manganese steel is ≥12 mm, the welding method further includes preheating the ultra-low temperature high manganese steel.

[0020] Compared with the prior art, the present invention has at least the following beneficial effects:

[0021] The welding wire steel for ultra-low temperature high manganese steel welding provided in the embodiment of the present application optimizes the design of the welding wire composition and adds a relatively high Mn element, so that the steel obtains a stable austenite structure at room temperature to ensure low-temperature toughness, only adds a small amount of Ni element to further improve the low-temperature toughness, does not add high melting point elements such as W, and transitions a small amount of alloy elements such as C, N, Ti, V, Nb to the weld through the welding wire, so that the weld forms nitrides, carbides, etc. at high temperatures, pins the grain boundaries, effectively prevents the growth of austenite grains, reduces the austenite grain size, and improves the low-temperature impact toughness of the weld. The inventors have found through many experiments that the welding wire composition disclosed in the present invention can obtain a weld that meets the following requirements: tensile strength ≥800Mpa; yield strength ≥435Mpa; -196℃ impact energy ≥68J; and, a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, and avoid slag inclusion in the weld. In addition, the welding wire steel of the present application is not copper-plated, and compared with the copper-plated welding wire in the prior art, it produces less welding smoke and poses less health hazards to welding operators. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without paying creative work.

[0023] Figure 1 This is a schematic diagram of the groove structure in the embodiment of the fourth aspect of the present application;

[0024] Figure 2 It is a schematic diagram of the structure of the welding joint in the fourth aspect embodiment.

[0025] In the accompanying drawings, the drawings may not be drawn according to the actual scale. Among them, the reference numerals in the drawings are:

[0026] a: plate thickness; d: assembly gap; α: groove angle; 1: base layer; 2: filling layer; 3: cover layer. DETAILED DESCRIPTION

[0027] The following detailed description and drawings of the embodiments of the present application are used to illustrate the principles of the present application, but cannot be used to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0028] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" does not require verticality in the strict sense, but may include allowable errors. "Parallel" does not require parallelism in the strict sense, but may include allowable errors.

[0029] Due to the late application of ultra-low temperature high manganese steel Mn24, welding materials and welding processes are not mature. As for the existing ultra-low temperature high manganese steel Mn24 welding materials, in addition to adding a high content of Mn elements, high contents of Ni and W elements are also added, the amount of alloy added is large, and the alloy cost is high; in addition, there are problems such as large work hardening, difficult welding wire processing, increased welding smoke caused by copper plating of welding wire, and increased health hazards to welding operators. Examples are as follows:

[0030] The solid tungsten inert gas arc welding wire (authorization announcement number CN107009046B) invented by Wang Honghong and others from Wuhan University of Science and Technology for ultra-low temperature high manganese steel welding has good low-temperature toughness of the weld metal and good strength matching with the base material. However, in addition to the Mn content of up to 26%, the Ni content of this welding wire is as high as 10%, and the welding material cost is extremely high.

[0031] The high manganese steel fully automatic submerged arc welding solid core welding wire for preparing LNG storage tanks invented by Wang Honghong and others from Wuhan University of Science and Technology (authorization announcement number CN107052618B) has good low-temperature toughness of the weld metal and good strength matching with the base material. However, in addition to containing 26% Mn, the welding wire also contains 8% Ni and 5% W, resulting in extremely high welding material costs.

[0032] The CO2 gas shielded welding wire for ultra-low temperature high manganese steel invented by Xiao Bingzheng et al. of Nangang (publication number CN113634948A) has good low-temperature toughness of the weld metal and good matching with the parent material. However, in addition to the Mn content of up to 25%, the Ni content of the welding wire is as high as 6%, and the welding material cost is high. Moreover, the welding wire is a copper-plated welding wire, which will increase the amount of smoke during the welding process. The copper smoke is very harmful to the health of welding operators, causing metal fume fever and respiratory irritation symptoms. Long-term inhalation may also cause lung tissue fibrosis.

[0033] In view of this, the embodiments of the present application provide a welding wire steel, welding wire and its preparation method and welding method for ultra-low temperature high manganese steel welding. The welding wire steel for ultra-low temperature high manganese steel welding provided in the embodiments of the present application adds a relatively high Mn element so that the steel obtains a stable austenite structure at room temperature and ensures low-temperature toughness. Only a small amount of Ni element is added to further improve the low-temperature toughness. No high melting point elements such as W are added, and a small amount of alloy elements such as C, N, Ti, V, and Nb are transitioned to the weld through the welding wire, so that the weld forms nitrides, carbides, etc. at high temperatures, pins the grain boundaries, effectively prevents the growth of austenite grains, reduces the austenite grain size, and improves the low-temperature impact toughness of the weld. The inventor has found through many experiments that the welding wire composition disclosed in the present invention can obtain a weld that meets the following requirements: tensile strength ≥800Mpa; yield strength ≥435Mpa; -196°C impact energy ≥68J; and, a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, avoid slag inclusion in the weld, and thus improve the quality of the weld. In addition, the welding wire steel of the present application is not copper-plated, and compared with the copper-plated welding wire in the prior art, it produces less welding smoke and poses less health hazards to welding operators.

[0034] Welding wire steel for ultra-low temperature high manganese steel welding

[0035] In a first aspect, an embodiment of the present application provides a welding wire steel for ultra-low temperature high manganese steel welding, comprising the following components in percentage by mass: C, 0.05% to 0.1%; Si, 0.5% to 0.6%; Mn, 24% to 25%; P≤0.01%; S≤0.01%; Al, 0.05% to 0.1%; Ni, 0.12% to 0.2%; N, 0.02% to 0.06%; Ti, 0.08% to 0.15%; V, 0.08% to 0.15%; Nb, 0.08% to 0.15%; Mo, 0.05% to 0.1%; the remainder is Fe and unavoidable impurities.

[0036] The composition design idea of ​​the welding wire steel for ultra-low temperature high manganese steel welding provided in the embodiment of the present application is as follows:

[0037] A relatively high content of Mn (24-25%) is added to the welding wire to obtain a stable austenite structure at room temperature; and a certain amount of C and N elements are added to stabilize austenite and inhibit phase transformation, so that the weld has excellent low-temperature toughness; however, in order to ensure less carbide precipitation and thus good plasticity and toughness, the C content of the welding wire is controlled at ≤0.1%; and the N element cannot be too high, otherwise nitrogen pores are likely to appear, so N is controlled to be ≤0.06%. Exemplarily, the mass percentage of the Mn element can be 24%, 24.1%, 24.2%, 24.3%, 24.4%, 24.5%, 24.6%, 24.7%, 24.8%, 24.9% or 25%, or it can be a value within the range between any two of the above values.

[0038] Considering the high cost of Ni alloy, the present application adds a small amount of Ni to the welding wire, which can effectively improve the low temperature toughness and has a certain solid solution strengthening effect; the content of Ni is controlled to be Ni≤0.2%. For example, the mass percentage of Ni can be 0.02%, 0.04%, 0.06%, 0.08%, 0.10%, 0.12%, 0.14%, 0.16%, 0.18% or 0.20%, or a value within the range between any two of the above values.

[0039] A small amount of Al element is added to the welding wire, and the oxide metallurgy principle of Al element is used to generate fine dispersed oxides in the weld, which pin the grain boundaries at high temperatures and prevent the growth of austenite grains, thereby ensuring good impact toughness at room temperature. In addition, Al element has a certain fine grain strengthening effect, which improves the strength of ultra-low temperature high manganese steel. However, too high Al element will cause defects such as slag inclusions in the weld. Therefore, the Al element is controlled at 0.05-0.1%.

[0040] Illustratively, the mass percentage of the Al element may be 0.05%, 0.06%, 0.07%, 0.08%, 0.09% or 0.1%, or a value within a range between any two of the above values.

[0041] A small amount of Ti, V, and Nb alloy elements are added to the welding wire. These alloy elements can combine with C and N elements to form dispersed nano-scale carbon and nitrides, such as TiN and NbC, which can hinder the growth of austenite grains at high temperatures. However, considering the addition amount of C and N, the combination effect is limited. Therefore, Ti, V, and Nb alloy elements should not be added too much, and should be controlled at 0.08-0.15%.

[0042] Illustratively, the mass percentage of the Ti element may be 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, or a value within a range between any two of the above values.

[0043] Illustratively, the mass percentage of the V element may be 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, or a value within a range between any two of the above values.

[0044] Illustratively, the mass percentage of the Nb element may be 0.08%, 0.09%, 0.10%, 0.11%, 0.12%, 0.13%, 0.14% or 0.15%, or a value within a range between any two of the above values.

[0045] A small amount of Mo element is added to the welding wire to work synergistically with Ti element to improve the low temperature toughness of the weld, and Mo is controlled between 0.05 and 0.1%.

[0046] Illustratively, the mass percentage of the Mo element may be 0.05%, 0.06%, 0.07%, 0.08%, 0.09% or 0.1%, or a value within a range between any two of the above values.

[0047] Si and Mn elements have a combined deoxidation effect, consuming O elements in the weld and reducing the probability of O elements combining with Al elements, thereby reducing the number and size of Al oxides; in addition, Mn elements can combine with S elements to eliminate the harmful effects of S elements; Si elements can improve the fluidity of weld metal and reduce defects such as slag inclusions and unfusion in welds; but too high Si elements will reduce the toughness of the weld, so Si≤0.6%.

[0048] Illustratively, the mass percentage of Si element may be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% or 0.60%, or a value within a range between any two of the above values.

[0049] S and P are impurity elements, especially S, which is easy to form FeS and MnS impurities. Both S and P elements are strictly controlled to be below 0.01%.

[0050] In summary, the welding wire steel for ultra-low temperature high manganese steel welding provided in the embodiment of the present application optimizes the design of the welding wire composition and adds a higher Mn element, so that the steel obtains a stable austenite structure at room temperature to ensure low-temperature toughness, only adds a small amount of Ni element to further improve the low-temperature toughness, does not add high-melting point elements such as W, and transitions a small amount of C, N, Ti, V, Nb and other alloy elements to the weld through the welding wire, so that the weld forms nitrides, carbides, etc. at high temperatures, pins the grain boundaries, effectively prevents the growth of austenite grains, reduces the austenite grain size, and improves the low-temperature impact toughness of the weld. The inventor has found through many experiments that the welding wire composition disclosed in the present invention can obtain a weld that meets the following requirements: tensile strength ≥800Mpa; yield strength ≥435Mpa; -196℃ impact energy ≥68J; and, a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, and avoid slag inclusion in the weld. In addition, the welding wire steel of the present application is not copper-plated, and compared with copper-plated welding wires of other patents, it produces less welding smoke and poses less health hazards to welding operators.

[0051] In order to achieve that the welding wire steel used for ultra-low temperature high manganese steel welding can meet the use requirements of the welding wire, the welding wire steel used for welding in the embodiment of the present application meets at least one of the following characteristics: (1) tensile strength ≥ 800Mpa; (2) yield strength ≥ 435Mpa; (3) -196℃ impact energy ≥ 68J.

[0052] In a second aspect, an embodiment of the present application provides a welding wire for ultra-low temperature high manganese steel welding, which is prepared from the aforementioned welding wire steel and includes the following components in percentage by mass:

[0053] C, 0.05~0.1%; Si, 0.5~0.6%; Mn, 24%~25%; P≤0.01%; S≤0.01%;

[0054] Al, 0.05% ~ 0.1%; Ni, 0.12 ~ 0.2%; N, 0.02 ~ 0.06%; Ti, 0.08% ~ 0.15%; V, 0.08% ~ 0.15%; Nb, 0.08% ~ 0.15%; Mo, 0.05% ~ 0.1%; the balance is Fe and unavoidable impurities.

[0055] According to the embodiments of the present application, the chemical composition of the welding wire is optimized, which is suitable for ultra-low temperature high manganese steel welding. A higher Mn element is added to enable the steel to obtain a stable austenite structure at room temperature to ensure low-temperature toughness. Only a small amount of Ni element is added to further improve the low-temperature toughness. No high-melting point elements such as W are added, and a small amount of alloy elements such as C, N, Ti, V, and Nb are transitioned to the weld through the welding wire, so that the weld forms nitrides, carbides, etc. at high temperatures, pins the grain boundaries, and effectively prevents the growth of austenite grains, reduces the austenite grain size, and improves the low-temperature impact toughness of the weld. The inventors have found through many experiments that the welding wire composition disclosed in the present invention can obtain welds that meet the following requirements: tensile strength ≥800Mpa; yield strength ≥435Mpa; -196℃ impact energy ≥68J; and, a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, and avoid slag inclusion in the weld. In addition, the welding wire steel of the present application is not copper-plated, and compared with the copper-plated welding wire in the prior art, it produces less welding smoke and poses less health hazards to welding operators.

[0056] In a third aspect, an embodiment of the present application provides a method for preparing a welding wire for ultra-low temperature high manganese steel welding, comprising the following steps:

[0057] The molten steel is subjected to converter smelting, refining, continuous casting and rolling to obtain welding wire steel for ultra-low temperature high manganese steel welding, wherein the welding wire steel for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24%-25%; P≤0.01%; S≤0.01%; Al, 0.05%-0.1%; Ni, 0.12-0.2%; N, 0.02-0.06%; Ti, 0.08%-0.15%; V, 0.08%-0.15%; Nb, 0.08%-0.15%; Mo, 0.05%-0.1%; the balance is Fe and inevitable impurities, and the balance is Fe and inevitable impurities;

[0058] The welding wire steel for ultra-low temperature high manganese steel welding is rolled into wire rods and annealed;

[0059] The wire rod is drawn and polished to obtain welding wire for ultra-low temperature high manganese steel welding.

[0060] According to the embodiments of the present application, the wire rod can be rolled into a wire rod with a diameter of 3mm-6mm, which can facilitate the subsequent production of the wire rod into welding wire for ultra-low temperature high manganese steel welding.

[0061] Annealing the wire rod can improve the processability of the wire rod.

[0062] The welding wire for ultra-low temperature high manganese steel welding prepared by the embodiment of the present application optimizes the chemical composition of the welding wire for welding, and is suitable for ultra-low temperature high manganese steel welding. Through the design and optimization of the welding wire composition, a higher Mn element is added to make the steel obtain a stable austenite structure at room temperature, ensure low temperature toughness, and only add a small amount of Ni element to further improve the low temperature toughness. No high melting point elements such as W are added, and a small amount of alloy elements such as C, N, Ti, V, and Nb are transitioned to the weld through the welding wire, so that the weld forms nitrides, carbides, etc. at high temperatures, pins the grain boundaries, effectively prevents the growth of austenite grains, reduces the size of austenite grains, and improves the low temperature impact toughness of the weld. In addition, a small amount of Si elements are transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, and avoid slag inclusion in the weld. In addition, the welding wire steel of the present application is not copper-plated, and compared with the copper-plated welding wire of the prior art, there is less welding smoke and less health damage to welding operators.

[0063] In a fourth aspect, an embodiment of the present application provides a method for welding ultra-low temperature high manganese steel, comprising the following steps:

[0064] A V-shaped groove is formed on ultra-low temperature high manganese steel to be welded of equal thickness, wherein the angle α of the V-shaped groove ranges from 50° to 70°;

[0065] The ultra-low temperature high manganese steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the ultra-low temperature high manganese steel to be welded is in the range of 1 to 3 mm;

[0066] The end of the aforementioned welding wire is placed close to the part to be welded of the ultra-low temperature high manganese steel. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the surface to be welded of the ultra-low temperature high manganese steel to achieve welding.

[0067] In some embodiments, steel plates with a thickness of 5 mm or more need to be beveled, while steel plates with a thickness of ≤4 mm do not need to be beveled.

[0068] According to the embodiment of the present application, during the welding process, the number of welding layers and passes is reasonably arranged according to the plate thickness. For example, Figure 1 and Figure 2 As shown in the figure, there are three welding layers, namely, base layer, filling layer and cover layer, of which base layer is welded 1 time, filling layer is welded 2 times and cover layer is welded 3 times. Multi-pass welding with narrow welds is adopted to avoid swinging, improve the protective effect of shielding gas, reduce the burning loss of alloy elements, further reduce defects such as weld slag inclusion and ensure the impact toughness of welds.

[0069] The present application adopts metal arc welding in combination with welding wire to weld ultra-low temperature high manganese steel, optimizes the chemical composition of the welding wire, is suitable for welding ultra-low temperature high manganese steel, and is applied to welding ultra-low temperature high manganese steel to improve the low-temperature impact performance of the weld.

[0070] It is understandable that the steel within the groove and the vicinity is ground, preferably the steel within the groove and the vicinity of 30 mm is ground, and rust, oil stains, etc. can be removed by grinding to reduce the impact of rust, oil stains, etc. on welding quality.

[0071] In some embodiments, the diameter of the welding wire for ultra-low temperature high manganese steel welding is 1.4 mm. According to the embodiment of the present application, compared with the welding wire with a diameter of φ1.2 mm or less, the welding wire with a diameter of φ1.4 mm has more advantages in the process of drawing and reducing the diameter; because it has less work hardening, less damage to the wire drawing die, and the number of annealing times and annealing costs required for the welding wire in the process of repeated drawing and reducing the diameter are lower, thereby reducing the difficulty of welding wire processing and reducing the production cost of welding wire; in addition, the welding wire with a diameter of φ1.4 mm has higher welding efficiency during the welding process.

[0072] In order to match the welding wire for ultra-low temperature high manganese steel welding with a diameter of 1.4 mm, in some embodiments, during the welding process, the welding current of the welding power source has a value range of 120 to 180A, and the welding voltage has a value range of 13 to 24V. For example, the welding current can be 120A, 130A, 140A, 150A, 160A, 170A, 180A, and the welding voltage can be 14V, 15V, 16V, 18V, 19V, 20V, 21V, 22V, 23V, and the use of smaller welding parameters, small current, and short arc can reduce the burning of alloy elements, thereby reducing defects such as slag inclusions in the weld; and it can reduce welding smoke, improve the welding working environment, and reduce the health hazards of welding operators.

[0073] In some embodiments, the shielding gas uses a 95% Ar + 5% CO2 mixed gas. According to the embodiment of the present application, the 95% Ar + 5% CO2 mixed gas is more conducive to the welding of ultra-low temperature high manganese steel, because 95% Ar + 5% CO2 has lower oxidizing properties, which can reduce the burning of alloy elements, especially the burning of Al elements, and reduce defects such as weld slag inclusions. Compared with the 80% Ar + 20% CO2 mixed gas, the 95% Ar + 5% CO2 mixed gas has lower oxidizing properties, which can reduce the burning of alloy elements, reduce defects such as weld slag inclusions, and improve the transition of alloy elements to the weld, thereby ensuring the impact toughness of the weld.

[0074] In some embodiments, when the thickness of the ultra-low temperature high manganese steel is ≥12 mm, the welding method further comprises preheating the ultra-low temperature high manganese steel. By preheating the ultra-low temperature high manganese steel, the cracking tendency can be reduced. For example, the ultra-low temperature high manganese steel can be preheated by flame, ceramic heating pad, etc., and the preheating temperature is 100°C to 120°C.

[0075] On the one hand, the embodiment of the present application optimizes the welding process, adopts a shielding gas with lower oxidizing property, and adopts smaller welding parameters to avoid swinging, reduce element burnout, reduce welding smoke, improve the welding working environment, and reduce the health hazards of welding operators; on the other hand, through the optimization of the welding wire composition design, only a small amount of Ni element is added, and no high melting point elements such as W are added. A small amount of alloy elements such as C, N, Ti, V, Nb are transitioned to the weld through the welding wire, so that nitrides, carbides, etc. are formed in the weld at high temperature, pinning the grain boundaries, effectively preventing the growth of austenite grains, reducing the austenite grain size, and improving the low-temperature impact toughness of the weld. In addition, a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of slag, and avoid slag inclusion in the weld.

[0076] Example

[0077] The following examples more specifically describe the disclosure of the present application, which are intended for illustrative purposes only, as it will be apparent to those skilled in the art that various modifications and variations are possible within the scope of the disclosure of the present application. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by weight, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing, and the instruments used in the examples are commercially available.

[0078] Example 1

[0079] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.06%; Si: 0.56%; Mn: 24.8%; P: 0.004%; S: 0.001%; ​​Al: 0.08%; Ni: 0.18%; N: 0.04%; Ti: 0.08%; V: 0.11%; Nb: 0.10%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0080] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0081] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0082] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 5 mm, and the angle α of the V-shaped groove is 60°;

[0083] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is 2 mm;

[0084] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0085] The welding current is controlled at 120A, the welding voltage is controlled at 14V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0086] Example 2

[0087] A welding wire for ultra-low temperature high manganese steel welding, comprising the following components in mass percentage: A welding wire, comprising the following components in mass percentage: C: 0.08%; Si: 0.58%; Mn: 24.6%; P: 0.002%; S: 0.001%; ​​Al: 0.06%; Ni: 0.19%; N: 0.04%; Ti: 0.09%; V: 0.12%; Nb: 0.11%; Mo: 0.09%; the balance is Fe and unavoidable impurities.

[0088] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0089] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0090] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 8 mm, and the angle α of the V-shaped groove ranges from 60°;

[0091] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is in the range of 1.6 mm;

[0092] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0093] The welding current is controlled at 140A, the welding voltage is controlled at 20V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0094] Example 3

[0095] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.06%; Si: 0.57%; Mn: 24.5%; P: 0.003%; S: 0.001%; ​​Al: 0.07%; Ni: 0.18%; N: 0.05%; Ti: 0.11%; V: 0.1%; Nb: 0.1%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0096] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0097] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0098] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 12 mm, and the angle α of the V-shaped groove is in the range of 55°;

[0099] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is in the range of 1.8 mm;

[0100] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0101] The welding current is controlled at 160A, the welding voltage is controlled at 22V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0102] Comparative Example 1

[0103] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.05%; Si: 0.3%; Mn: 24.8%; P: 0.004%; S: 0.001%; ​​Al: 1%; Ni: 0.18%; N: 0.04%; Ti: 0.08%; V: 0.11%; Nb: 0.1%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0104] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0105] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0106] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 12 mm, and the angle α of the V-shaped groove is 55°;

[0107] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is 1.8 mm;

[0108] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0109] The welding current is controlled at 160A, the welding voltage is controlled at 22V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0110] Comparative Example 2

[0111] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.05%; Si: 0.56%; Mn: 24.8%; P: 0.004%; S: 0.001%; ​​Al: 0.08%; Ni: 0.05%; N: 0.04%; Ti: 0.005%; V: 0.005%; Nb: 0.1%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0112] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0113] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0114] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 12 mm, and the angle α of the V-shaped groove is 55°;

[0115] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is 1.8 mm;

[0116] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0117] The welding current is controlled at 160A, the welding voltage is controlled at 22V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0118] Comparative Example 3

[0119] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.1%; Si: 0.56%; Mn: 24.8%; P: 0.004%; S: 0.001%; ​​Al: 0.08%; Ni: 0.18%; N: 0.04%; Ti: 0.21%; V: 0.12%; Nb: 0.11%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0120] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0121] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0122] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 12 mm, and the angle α of the V-shaped groove is 55°;

[0123] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is 1.8 mm;

[0124] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0125] The welding current is controlled at 160A, the welding voltage is controlled at 22V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 95% Ar + 5% CO2.

[0126] Comparative Example 4

[0127] A welding wire for ultra-low temperature high manganese steel welding comprises the following components by mass percentage: C: 0.06%; Si: 0.56%; Mn: 24.8%; P: 0.004%; S: 0.001%; ​​Al: 0.08%; Ni: 0.18%; N: 0.04%; Ti: 0.11%; V: 0.1%; Nb: 0.1%; Mo: 0.08%; the balance is Fe and unavoidable impurities.

[0128] The preparation method of the above welding wire can use the existing mature method, including - refining - continuous casting and rolling - annealing treatment into wire rod, and then drawing - polishing, winding into welding wire. For details, please refer to "Guide to Selection of Welding Wire"; Chemical Industry Press. 2011.5.

[0129] The welding method of ultra-low temperature high manganese steel comprises the following steps:

[0130] A V-shaped groove is formed on the ultra-low temperature high manganese steel to be welded with a thickness of 12 mm, and the angle α of the V-shaped groove is 55°;

[0131] Fix the ultra-low temperature high manganese steel to be welded, butt-clamp the steel plates, and the root gap d of the ultra-low temperature high manganese steel to be welded is 1.8 mm;

[0132] The end of the welding wire is placed close to the welding part of the ultra-low temperature high manganese steel to be welded. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the welding surface of the ultra-low temperature high manganese steel to be welded to achieve welding.

[0133] The welding current is controlled at 160A, the welding voltage is controlled at 22V, and the diameter is For welding wires with small diameter, the shielding gas is a mixture of 80% Ar + 20% CO2.

[0134] The welding wires manufactured in Examples 1 to 3 were tested. The test results are shown in Table 1. The tests are as follows:

[0135] Table 1 Test results of Examples 1 to 3 and Comparative Examples 1 to 4

[0136]

[0137] As can be seen from Table 1, Examples 1 to 3 of the present application optimize the design of the welding wire composition, only add a small amount of Ni element, and transition a small amount of C, N, Ti, V, Nb and other alloy elements to the weld through the welding wire to improve the low-temperature impact toughness of the weld, and a small amount of Si element is transitioned to the weld through the welding wire to improve the fluidity of the molten pool, promote the floating of the slag, and avoid slag inclusion in the weld; the welding process is optimized, a lower oxidizing shielding gas is used, and smaller welding parameters are used to avoid swinging, reduce element burnout, reduce welding smoke, improve the welding working environment, and reduce health hazards to welding operators.

[0138] In Comparative Example 1, the welding wire composition is high Al and low Si, the molten pool fluidity is poor, and there are slag inclusions in the weld, resulting in low strength and poor impact toughness; the welding wire composition of Comparative Example 2 is low Ni, low Ti and V, and the impact toughness is poor; the welding wire composition of Comparative Example 3 is high Ti and C, forming large block inclusions, and the impact toughness is poor; in Comparative Example 4, the protective gas is highly oxidizing, the alloy elements are severely burned, and the weld strength is low; moreover, there are more weld oxides, and there are slag inclusions in the weld, and the impact toughness is poor.

[0139] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A welding wire steel for ultra-low temperature high manganese steel welding, characterized in that: The invention comprises the following components in percentage by mass: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24%-25%; P≤0.01%; S≤0.01%; Al, 0.05%~0.1%; Ni, 0.12~0.2%; N, 0.02~0.06%; Ti, 0.08%~0.15%; V, 0.08%~0.15%; Nb, 0.08%~0.15%; Mo, 0.05%~0.1%; the balance is Fe and unavoidable impurities.

2. The welding wire steel for ultra-low temperature high manganese steel welding according to claim 1, characterized in that: The welding wire steel meets at least one of the following characteristics: (1) Tensile strength ≥800Mpa; (2) Yield strength ≥435Mpa; (3) Impact energy at -196℃≥68J.

3. A welding wire for ultra-low temperature high manganese steel welding, characterized in that: The invention comprises the following components in percentage by mass: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24%-25%; P≤0.01%; S≤0.01%; Al, 0.05%~0.1%; Ni, 0.12~0.2%; N, 0.02~0.06%; Ti, 0.08%~0.15%; V, 0.08%~0.15%; Nb, 0.08%~0.15%; Mo, 0.05%~0.1%; the balance is Fe and unavoidable impurities.

4. A method for preparing a welding wire for ultra-low temperature high manganese steel welding, characterized in that: The steps include: The molten steel is subjected to converter smelting, refining, continuous casting and rolling to obtain welding wire steel for ultra-low temperature high manganese steel welding, wherein the welding wire steel comprises the following components by mass percentage: C, 0.05-0.1%; Si, 0.5-0.6%; Mn, 24%-25%; P≤0.01%; S≤0.01%; Al, 0.05%~0.1%; Ni, 0.12~0.2%; N, 0.02~0.06%; Ti, 0.08%~0.15%; V, 0.08%~0.15%; Nb, 0.08%~0.15%; Mo, 0.05%~0.1%, the balance is Fe and unavoidable impurities; The welding wire steel for ultra-low temperature high manganese steel welding is rolled into wire rods and annealed; The wire rod is subjected to drawing-polishing treatment to obtain welding wire for ultra-low temperature high manganese steel welding.

5. A welding method for ultra-low temperature high manganese steel, characterized in that: The steps include: A V-shaped groove is formed on ultra-low temperature high manganese steel to be welded of equal thickness, wherein the angle α of the V-shaped groove ranges from 50° to 70°; The ultra-low temperature high manganese steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the ultra-low temperature high manganese steel to be welded is in the range of 1 to 3 mm; The end of the welding wire made of the welding wire steel for welding ultra-low temperature high manganese steel as described in claim 1 or 2 or the welding wire as described in claim 3 is placed close to the part to be welded of the ultra-low temperature high manganese steel. Under the action of the welding power supply, an arc is formed between the end of the welding wire and the surface to be welded of the ultra-low temperature high manganese steel to be welded, thereby achieving welding.

6. The welding method of ultra-low temperature high manganese steel according to claim 5, characterized in that: The diameter of the welding wire is 1.4 mm.

7. The welding method of ultra-low temperature high manganese steel according to claim 5, characterized in that: During the welding process, the welding current of the welding power source ranges from 120 to 180A, and the welding voltage ranges from 13 to 24V.

8. The welding method of ultra-low temperature high manganese steel according to claim 5, characterized in that: During the welding process, the shielding gas is a 95% Ar + 5% CO2 mixed gas.

9. The welding method of ultra-low temperature high manganese steel according to claim 5, characterized in that: When the thickness of the ultra-low temperature high manganese steel is ≥12 mm, the welding method further comprises preheating the ultra-low temperature high manganese steel.

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