Welding wire steel, welding wire, preparation method and welding method

Abstract

The present application provides a welding wire steel, welding wire, preparation method and welding method. Among them, the welding wire steel includes the following components in percentage by mass: 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities. The present application optimizes the design of welding wire composition, utilizes the welding wire to transition alloy elements such as Cu and Cr to the weld during the welding process, improves the corrosion resistance of the weld, and transitions the Si element to the weld through the welding wire, thereby improving the fluidity of the molten pool, promoting the floating of the slag, and avoiding slag inclusion in the weld.

Description

Technical Field

[0001] The present application relates to the technical field of steel materials, and in particular to a welding wire steel, a welding wire, a preparation method and a welding method. Background Art

[0002] With the development of the national economy and the upgrading of the industrial structure, high-aluminum steel has been widely used in key areas such as automobiles, energy, and electricity due to its high lightness, high toughness, low density, and low cost.

[0003] High aluminum steel contains a high mass fraction of Al, which reduces the density of the steel. In addition, Al can form a passivation film to improve corrosion resistance. However, during the welding process of high aluminum steel, due to the high temperature of the welding pool, the affinity of aluminum to oxygen is much greater than that of other alloying elements, resulting in severe burnout of Al, which reduces the corrosion resistance of the steel and increases the occurrence of defects such as weld slag inclusions. Summary of the invention

[0004] The embodiments of the present application provide a welding wire steel, a welding wire, a preparation method and a welding method, which aim to improve the corrosion resistance of the weld and reduce slag inclusion in the weld.

[0005] In a first aspect, an embodiment of the present application provides a welding wire steel for welding, characterized in that it includes the following components in percentage by mass: 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0006] According to an embodiment of the first aspect of the present application, the tensile strength is ≥460 MPa, the yield strength is ≥350 MPa, the elongation is ≥23%, and the impact energy at -20°C is ≥36 J.

[0007] In a first aspect, an embodiment of the present application provides a welding wire, comprising the following components in percentage by weight:

[0008] 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0009] According to an embodiment of the second aspect of the present application, a copper layer is plated on the surface of the welding wire, and a thickness d of the copper layer ranges from 0.18 μm to 0.20 μm.

[0010] In a third aspect, an embodiment of the present application provides a method for preparing a welding wire, comprising the following steps:

[0011] The molten steel is subjected to converter smelting-refining-continuous casting to obtain welding wire steel, which comprises the following components by mass percentage: 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0012] Rolling the welding wire steel into wire rods and performing annealing treatment;

[0013] The wire rod is subjected to drawing-copper plating-polishing treatment to obtain welding wire.

[0014] In a fourth aspect, an embodiment of the present application provides a high-aluminum steel welding method, comprising the following steps:

[0015] A V-shaped groove is formed on high-aluminum steel to be welded of equal thickness, wherein the angle α of the V-shaped groove ranges from 50° to 70°;

[0016] The high-aluminum steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the high-aluminum steel to be welded is in the range of 1 to 3 mm;

[0017] The end of the aforementioned welding wire is placed close to the welding part of the high-aluminum steel to be welded. Under the action of the welding power supply, a main arc is formed between the end of the welding wire and the welding surface of the high-aluminum steel to be welded to achieve welding.

[0018] According to an embodiment of the fourth aspect of the present application, the diameter of the welding wire is 1.0 mm.

[0019] 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 80 to 160A, and the welding voltage is in the range of 15 to 22V.

[0020] According to the embodiment of the fourth aspect of the present application, during the welding process, the shielding gas is 95% Ar + 5% CO 2 Mixed gas.

[0021] According to an embodiment of the fourth aspect of the present application, when the thickness of the high-aluminum steel is ≥12 mm, the welding method further includes preheating the high-aluminum steel.

[0022] Compared with the prior art, the present invention has at least the following beneficial effects:

[0023] The welding wire steel provided in the embodiment of the present application optimizes the composition design of the steel material, and transitions alloy elements such as Cu and Cr to the weld through the welding wire to improve the corrosion resistance of the weld. In addition, the 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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.

[0025] Figure 1 This is a schematic diagram of the groove structure in the embodiment of the fourth aspect of the present application;

[0026] Figure 2 It is a schematic diagram of the structure of the welding joint in the fourth aspect embodiment.

[0027] In the accompanying drawings, the drawings may not be drawn according to the actual scale. Among them, the reference numerals in the drawings are:

[0028] a: plate thickness; d: assembly gap; α: groove angle; 1: base layer; 2: filling layer; 3: cover layer. DETAILED DESCRIPTION

[0029] 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.

[0030] 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.

[0031] High aluminum steel contains a high mass fraction of Al elements. For example, the chemical composition of high aluminum steel developed to meet the lightweight requirements of containers is as follows: C≤0.05, Si≤0.3, Mn≤1.2, Al 3.9~4.2, P≤0.01, S≤0.001, Cu≤0.02, Ni≤0.02, Cr≤0.03, Nb≤0.02, V≤0.01, Ti≤0.02, Mo≤0.01, N≤0.01; a high mass fraction of Al elements reduces the density of steel, and Al elements can form a passivation film to improve corrosion resistance. However, during the welding process of high aluminum steel, due to the high temperature of the welding pool, the affinity of aluminum to oxygen is much greater than that of other alloying elements, resulting in serious burnout of Al elements, which reduces the corrosion resistance of the steel and increases the occurrence of defects such as weld slag inclusions.

[0032] In view of this, the embodiments of the present application provide a welding wire steel, a welding wire, a preparation method and a welding method. The welding wire steel provided in the embodiments of the present application optimizes the composition design of the steel material, and transitions alloy elements such as Cu and Cr to the weld through the welding wire to improve the corrosion resistance of the weld. In addition, the 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.

[0033] Welding wire steel

[0034] In a first aspect, an embodiment of the present application provides a welding wire steel for welding, comprising the following components in percentage by mass: 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0035] The composition design ideas of the welding wire steel provided in the embodiments of the present application are as follows:

[0036] In order to ensure strength, good plasticity and toughness and low hardening tendency, the C content in the welding wire steel is controlled at 0.05% to 0.1%. For example, the mass percentage of the C element can be 0.05%, 0.06%, 0.07%, 0.08%, 0.09%, 0.1%, or any combination range of the above values.

[0037] Si and Mn elements have the effect of solid solution strength and combined deoxidation. They can consume O elements in the weld during welding and reduce the probability of O elements combining with Al elements. 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 unfused welds. However, too high Si elements will increase the brittleness of the weld. Therefore, considering comprehensively, the mass percentage of Si elements is controlled at 0.1% to 0.6%, and the mass percentage of Mn elements is controlled at 0.9% to 1.2%. For example, the mass percentage of Si elements can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% or 0.6%, or any combination of the above values. For example, the mass percentage of Mn elements is controlled at 0.9%, 1.0%, 1.1%, 1.2%, or any combination of the above values.

[0038] S and P are impurity elements, especially S, which is easy to form FeS and MnS impurities. The mass percentage of S in the welding wire is strictly controlled at 0.01%. For example, the mass percentage of S can be 0.001%, 0.002%, 0.003%, 0.004%, 0.005%, 0.007% or 0.009%, or any combination of the above values. Considering that P is beneficial to improving the corrosion resistance of the weld, the mass percentage of P is controlled to be less than or equal to 0.02%. For example, the mass percentage of P can be 0.001%, 0.005%, 0.008%, 0.01%, 0.015%, 0.017% or 0.019%, or any combination of the above values.

[0039] Cr element has a certain solid solution strengthening effect, which can improve the strength of the weld; most importantly, Cr element and O element form Cr 2 O 3 Protective film, improve the corrosion resistance of the weld; however, considering that the Cr element will affect the plasticity and toughness of the weld, it is controlled at 0.1% to 0.2%. For example, the mass percentage of the Cr element can be 0.1%, 0.12%, 0.14%, 0.16%, 0.18% or 0.2%, or any combination of the above values.

[0040] According to the anode passivation theory and Cu enrichment theory, the Cu element can effectively reduce the corrosion depth and corrosion rate of the weld and improve the corrosion resistance of the weld. Therefore, the Cu element of the welding wire is controlled at 0.3% to 0.6%. For example, the mass percentage of the Cr element can be 0.3%, 0.35%, 0.4%, 0.45%, 0.5% or 0.55%, or any combination of the above values.

[0041] Al has a certain fine grain strengthening effect, but too high Al content will cause defects such as weld slag inclusions, so the Al content is strictly controlled to 0.02% to 0.05%. For example, the mass percentage of Al can be 0.02%, 0.025%, 0.03%, 0.035%, 0.04%, 0.045% or 0.05%, or any combination of the above values.

[0042] Reduce the influence of Al element in the base material on the weld quality, and transfer alloy elements such as Cu and Cr to the weld through the welding wire to improve the corrosion resistance of the weld.

[0043] By optimizing the chemical composition of the welding wire steel, the embodiment of the present application can make the composition of the prepared welding wire transition to the weld through the welding wire to produce alloy elements that are beneficial to improving the corrosion resistance of the weld, thereby ensuring that the weld has the same corrosion resistance as Al4 steel.

[0044] In order to ensure that the welding wire steel can meet the use requirements of the welding wire, in some embodiments, the welding wire steel has a tensile strength ≥460MPa, a yield strength ≥350MPa, an elongation ≥23%, and an impact energy ≥36J at -20°C.

[0045] In a second aspect, an embodiment of the present application provides a welding wire, which is prepared from the aforementioned welding wire steel and includes the following components in percentage by weight:

[0046] 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0047] According to the embodiments of the present application, the chemical composition of the welding wire is optimized and is suitable for high-aluminum steel welding. The alloy elements that are beneficial to improving the corrosion resistance of the weld can be transitioned to the weld through the welding wire during the welding process, thereby ensuring that the weld has the same corrosion resistance as the high-aluminum steel.

[0048] In some embodiments, the surface of the welding wire is plated with a copper layer, and the thickness d of the copper layer ranges from 0.18 μm to 0.20 μm.

[0049] The welding wire provided in the embodiment of the present application adopts a copper plating process, which can improve the surface quality of the welding wire, enhance the electrical conductivity, prevent rust and corrosion on the surface of the welding wire, and extend the shelf life of the welding wire. On the other hand, the surface coating of the welding wire can also transfer the Cu element to the weld, which helps to improve the corrosion resistance of the weld. Considering the composition of high-aluminum steel, the thickness of the copper layer ranges from 0.18μm to 0.20μm, for example, the thickness of the copper layer is 0.18μm, 0.19μm or 0.20μm.

[0050] In a third aspect, an embodiment of the present application provides a method for preparing a welding wire, comprising the following steps:

[0051] The molten steel is subjected to converter smelting-refining-continuous casting to obtain welding wire steel, which comprises the following components by mass percentage: 0.05%≤C≤0.1%, 0.1%≤Si≤0.6%, 0.9%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.05%, 0.1%≤Cr≤0.2%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities.

[0052] The welding wire steel is rolled into wire rods and annealed.

[0053] The wire rod is subjected to drawing-copper plating-polishing treatment to obtain welding wire.

[0054] 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.

[0055] Annealing the wire rod can improve the processability of the wire rod.

[0056] The welding wire prepared by the embodiment of the present application optimizes the chemical composition of the welding wire, is suitable for high-aluminum steel welding, and can be used to transfer alloy elements that are beneficial to improving the corrosion resistance of the weld to the weld during the welding process, thereby ensuring that the weld has the same corrosion resistance as the high-aluminum steel. The preparation process is simple and suitable for mass production.

[0057] In a fourth aspect, an embodiment of the present application provides a high-aluminum steel welding method, comprising the following steps:

[0058] A V-shaped groove is formed on high-aluminum steel to be welded of equal thickness, wherein the angle α of the V-shaped groove ranges from 50° to 70°;

[0059] The high-aluminum steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the high-aluminum steel to be welded is in the range of 1 to 3 mm;

[0060] The end of the aforementioned welding wire is placed close to the welding part of the high-aluminum steel to be welded. Under the action of the welding power supply, a main arc is formed between the end of the welding wire and the welding surface of the high-aluminum steel to be welded to achieve welding.

[0061] 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, 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. Using narrow weld bead and multiple weld bead can avoid swinging, reduce the melting of base material and reduce the influence of Al element in base material on weld.

[0062] This application uses gas metal arc welding in combination with welding wire to weld aluminum steel with welding strips, optimizes the chemical composition of the welding wire, is suitable for high-aluminum steel welding, and can be used to transfer alloy elements that are beneficial to improving the corrosion resistance of the weld to the weld during the welding process through the welding wire, ensuring that the weld high-aluminum steel has the same corrosion resistance. Compared with welding methods such as arc welding and submerged arc welding, the welding heat input of gas metal arc welding is small; it reduces the melting of the base material, reduces the fusion ratio, reduces the burning of the Al element, and reduces defects such as weld slag caused by the burning of the Al element in the base material.

[0063] 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.

[0064] In some embodiments, the diameter of the welding wire is 1.0 mm. According to the embodiment of the present application, the welding wire with a diameter of φ1.0 mm is more conducive to the welding of high-aluminum steel. Compared with the welding wire with a diameter of φ1.2 mm and above, the welding wire with a diameter of φ1.0 mm can use lower welding parameters and lower welding heat input, thereby reducing the melting of the parent material during welding and reducing the influence of the Al element in the parent material on the welding quality; in addition, the use of the welding wire with a diameter of φ1.0 mm can also reduce welding spatter, reduce the grinding and slag removal time after welding, and improve production efficiency.

[0065] In order to match the welding wire with a diameter of 1.0 mm, in some embodiments, during the welding process, the welding current of the welding power source is in the range of 80 to 160 A, and the welding voltage is in the range of 15 to 22 V. For example, the welding current may be 80 A, 90 A, 100 A, 110 A, 120 A, 130 A or 140 A, and the welding voltage may be 16 V, 18 V, 19 V, 20 V or 21 V, and smaller welding parameters are used to reduce the burning of Al element in the base material and reduce defects such as slag inclusion in the weld.

[0066] In some embodiments, the protective gas is 95% Ar + 5% CO 2 Mixed gas. According to the embodiment of the present application, 95% Ar + 5% CO 2 The mixed gas is more conducive to the welding of high aluminum steel, because 95% Ar + 5% CO 2 It has lower oxidizability, which can reduce the burnout of alloy elements, especially the burnout of Al elements, and reduce defects such as slag inclusions in welds.

[0067] In some embodiments, when the thickness of the high aluminum steel is ≥12 mm, the welding method further comprises preheating the high aluminum steel. By preheating the high aluminum steel, the cracking tendency can be reduced. For example, the high aluminum steel can be preheated by flame, ceramic heating pad, etc., and the preheating temperature is 100°C to 120°C.

[0068] Example

[0069] 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.

[0070] Example 1

[0071] A welding wire comprises the following components by mass percentage: C: 0.08%, Si: 0.32%, Mn: 1.12%, P: 0.01%, S: 0.003%, Al: 0.022%, Cr: 0.12%, Cu: 0.6%, and the balance is Fe and inevitable impurities.

[0072] 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 - copper plating - polishing, and winding into welding wire. For details, please refer to the "Guide to Welding Wire Selection"; Chemical Industry Press. 2011.5.

[0073] The welding method of high aluminum steel comprises the following steps:

[0074] A V-shaped groove is formed on the high-aluminum steel to be welded with a thickness of 2 mm, and the angle α of the V-shaped groove is in the range of 60°;

[0075] The high aluminum steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the high aluminum steel to be welded is in the range of 2 mm;

[0076] The end of the welding wire is placed close to the welding part of the high-aluminum steel to be welded. Under the action of the welding power supply, a main arc is formed between the end of the welding wire and the welding surface of the high-aluminum steel to be welded to achieve welding.

[0077] The welding current is controlled at 100A, the welding voltage is controlled at 20V, a small diameter welding wire of φ1.0mm is used, and the shielding gas is 95% Ar+5% CO 2 Mixed gas.

[0078] Example 2

[0079] A welding wire comprises the following components by mass percentage: C: 0.05%, Si: 0.25%, Mn: 0.95%, P: 0.005%, S: 0.005%, Al: 0.03%, Cr: 0.17%, Cu: 0.4%, and the balance is Fe and inevitable 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 - copper plating - polishing, and winding into welding wire. For details, please refer to the "Guide to Welding Wire Selection"; Chemical Industry Press. 2011.5.

[0081] The welding method of high aluminum steel comprises the following steps:

[0082] A V-shaped groove is formed on the high-aluminum steel to be welded with a thickness of 3 mm, and the angle α of the V-shaped groove is in the range of 60°;

[0083] The high aluminum steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the high aluminum steel to be welded is in the range of 2 mm;

[0084] The end of the welding wire is placed close to the welding part of the high-aluminum steel to be welded. Under the action of the welding power supply, a main arc is formed between the end of the welding wire and the welding surface of the high-aluminum steel to be welded to achieve welding.

[0085] The welding current is controlled at 120A, the welding voltage is controlled at 20V, a small diameter welding wire of φ1.0mm is used, and the shielding gas is 95% Ar+5% CO 2 Mixed gas.

[0086] Example 3

[0087] A welding wire comprises the following components by mass percentage: C: 0.06%, Si: 0.46%, Mn: 1.05%, P: 0.015%, S: 0.006%, Al: 0.04%, Cr: 0.2%, Cu: 0.35%, and the balance is Fe and inevitable 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 - copper plating - polishing, and winding into welding wire. For details, please refer to the "Guide to Welding Wire Selection"; Chemical Industry Press. 2011.5.

[0089] The welding method of high aluminum steel comprises the following steps:

[0090] A V-shaped groove is formed on the high-aluminum steel to be welded with a thickness of 4 mm, and the angle α of the V-shaped groove is in the range of 65°;

[0091] The high aluminum steel to be welded is fixed, and the steel plates are butt-clamped, and the root gap d of the high aluminum steel to be welded is in the range of 2 mm;

[0092] The end of the welding wire is placed close to the welding part of the high-aluminum steel to be welded. Under the action of the welding power supply, a main arc is formed between the end of the welding wire and the welding surface of the high-aluminum steel to be welded to achieve welding.

[0093] The welding current is controlled at 100A, the welding voltage is controlled at 20V, a small diameter welding wire of φ1.0mm is used, and the shielding gas is 95% Ar+5% CO 2 Mixed gas.

[0094] The welding wires manufactured in Examples 1 to 3 were tested. The test results are shown in Table 1. The tests are as follows:

[0095] Table 1 Test results of Examples 1 to 3

[0096] Yield Strength tensile strength Elongation -20℃ impact energy Slag inclusion in weld Example 1 390 480 34 55 No slag inclusion Example 2 400 505 32 52 No slag inclusion Example 3 410 510 29 48 No slag inclusion

[0097] 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 suitable for high aluminum steel welding, characterized in that: The invention comprises the following components in percentage by mass: 0.05%≤C≤0.1%, 0.25%≤Si≤0.46%, 1.05%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.03%, 0.1%≤Cr≤0.17%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities; the welding wire steel suitable for high aluminum steel welding has a tensile strength of ≥460MPa, a yield strength of ≥350MPa, an elongation of ≥29%, and an impact energy of ≥36J at -20°C.

2. A welding wire suitable for high aluminum steel welding, characterized in that: The following components are included in the mass percentage: 0.05%≤C≤0.1%, 0.25%≤Si≤0.46%, 1.05%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.03%, 0.1%≤Cr≤0.17%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities; the welding wire suitable for high aluminum steel welding has a tensile strength of ≥460MPa, a yield strength of ≥350MPa, an elongation of ≥29%, and an impact energy of ≥36J at -20℃.

3. The welding wire suitable for high aluminum steel welding according to claim 2, characterized in that: The surface of the welding wire is plated with a copper layer, and the thickness d of the copper layer ranges from 0.18 μm to 0.20 μm.

4. A method for preparing a welding wire suitable for high-aluminum steel welding, characterized in that: The steps include: The molten steel is subjected to converter smelting-refining-continuous casting to obtain welding wire steel, wherein the welding wire steel comprises the following components by mass percentage: 0.05%≤C≤0.1%, 0.25%≤Si≤0.46%, 1.05%≤Mn≤1.2%, 0.01%≤P≤0.02%, S≤0.01%, 0.02%≤Al≤0.03%, 0.1%≤Cr≤0.17%, 0.3%≤Cu≤0.6%, and the balance is Fe and unavoidable impurities; Rolling the welding wire steel into wire rods and performing annealing treatment; The wire rod is subjected to drawing-copper plating-polishing treatment to obtain welding wire; the welding wire has a tensile strength of ≥460MPa, a yield strength of ≥350MPa, an elongation of ≥29%, and an impact energy of ≥36J at -20°C.

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

6. The high aluminum steel welding method according to claim 5, characterized in that: The diameter of the welding wire is 1.0 mm.

7. The high aluminum steel welding method according to claim 5, characterized in that: During the welding process, the welding current of the welding power source ranges from 80 to 160A, and the welding voltage ranges from 15 to 22V.

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

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

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