A welding method for high manganese steel and martensitic aging steel

Abstract

This invention provides a welding method for high-manganese steel and maraging steel. The welding wire composition for welding high-manganese steel and maraging steel is: C < 0.04 wt.%, Mn: 0.5–2.5 wt.%, Si < 0.9 wt.%, P: < 0.03 wt.%, S: < 0.03 wt.%, Cr: 22–25 wt.%, Ni: 12–14 wt.%, Mo: 2–3 wt.%, Cu < 0.75 wt.%, with the balance being iron. The welding method is CO2 gas shielded welding. This invention, by selecting welding electrodes and wires with suitable compositions and combining them with the control of welding methods and parameters, can obtain the optimal weld microstructure. This microstructure exhibits good fusion, free from welding defects such as cracks, inclusions, and porosity. It possesses excellent weldability and material composition, with the weld joint strength reaching over 500 MPa. This expands the application of high-manganese steel and maraging steel in more fields. It is easy to operate and has significant implications for advancing the national "dual-carbon" strategic goal.

Description

Technical Field

[0001] This invention belongs to the field of metal machining technology where there is essentially no cutting involved in the operation and transportation, and specifically relates to a welding method for high manganese steel and martensitic aging steel. Background Technology

[0002] Martensitic aging steel is an important member of ultra-high strength steels. It uses carbon-free or ultra-low carbon Fe-Ni martensite as its matrix and achieves strengthening by precipitating nano-reinforcing phases through aging treatment at moderate temperatures. Due to its advantages such as high strength, high hardness, high toughness, wear resistance, and good microstructural stability, it has been widely used in aerospace and other fields.

[0003] High-manganese steel's high plasticity, toughness, and work hardening capacity make it a core material for railway frogs. However, in areas subjected to strong impacts and high wear, such as the frog's frog rail and wing rails, this material suffers severe failure. Since high-manganese steel has lower strength and hardness compared to martensitic aging steel, a small amount of martensitic aging steel can be used as a substitute in the easily worn and impacted areas of the frog, while high-manganese steel is still used in other areas. By welding the two together, the problem of material failure can be hopefully solved.

[0004] Martensitic aging steel has good weldability and is suitable for almost all welding processes. It will not crack even without preheating before welding or post-weld treatment.

[0005] Currently, the welding of high-manganese steel and maraging steel has received almost no research, and there are very few reports in the literature. The welding process technology urgently needs to be addressed. Therefore, the following technical solution is proposed to fill this gap in the industry. Summary of the Invention

[0006] The technical problem solved by this invention is to provide a welding method for high manganese steel and martensitic aging steel, using an innovative welding electrode and wire material and applying a CO2 gas shielded welding method, thereby solving the technical problem of how to improve the welding mechanical properties and microstructure of high manganese steel and martensitic aging steel.

[0007] The technical solution adopted in this invention is: a welding method for high manganese steel and maraging steel, wherein the welding wire composition for welding high manganese steel and maraging steel is: C < 0.04 wt.%, Mn: 0.5-2.5 wt.%, Si < 0.9 wt.%, P: < 0.03 wt.%, S: < 0.03 wt.%, Cr: 22-25 wt.%, Ni: 12-14 wt.%, Mo: 2-3 wt.%, Cu < 0.75 wt.%, with the balance being iron; the welding method for welding high manganese steel and maraging steel is CO2 gas shielded welding.

[0008] In the above technical solution, preferably, the welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

[0009] In the above technical solution, preferably, the external current of the CO2 gas shielded welding is 160-165A and the arc voltage is 20-24V.

[0010] In the above technical solution, preferably, the high manganese steel and the martensitic aging steel are welded with a Y-shaped bevel; the angle of the Y-shaped bevel is 30° to 40°.

[0011] In the above technical solution, further: the composition of the high manganese steel is: C: 0.9-1.2 wt.%, Si: 0.3-0.8 wt.%, Mn: 11-14 wt.%, P: <0.03 wt.%, S: <0.03 wt.%, with the balance being Fe and unavoidable impurities.

[0012] In the above technical solution, further: the composition of the martensitic aging steel is: C < 0.1 wt.%, Ni: 16-19 wt.%, Co: 0-12 wt.%, Mo: 4-6 wt.%, Ti: 0.1-1.0 wt.%, with the balance being Fe and unavoidable impurities.

[0013] Advantages of this invention compared to existing technologies:

[0014] 1. By selecting welding rods and wires with suitable compositions and controlling welding methods and parameters, this invention can obtain the optimal weld structure. This structure has good fusion and is free from welding defects such as cracks, inclusions, and porosity. It has good welding performance and material composition, and the weld joint strength reaches more than 500 MPa.

[0015] 2. This invention is the first in China to study the welding method of high manganese steel and martensitic aging steel, which broadens the application of high manganese steel and martensitic aging steel in more fields.

[0016] 3. The welding process of this invention is easy to operate, requires no preheating before welding, and does not produce cracks without post-weld treatment. The welded structure has good properties and is of great significance to promoting the national "dual carbon" strategic goal. Attached Figure Description

[0017] Figure 1 This is a tensile stress-strain diagram of the welded joint of the present invention;

[0018] Figure 2 This is a microstructure diagram of the interface between the weld and high manganese steel in this invention.

[0019] Figure 3 This is a microstructure diagram of the interface between the weld and the martensitic aging steel of the present invention. Detailed Implementation

[0020] The following will refer to the appendices in the embodiments of the present invention. Figure 1-3 The technical solutions in the embodiments of the present invention are clearly and completely described herein. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] Example 1:

[0022] A welding method for high-manganese steel and maraging steel, wherein the welding wire composition for welding high-manganese steel and maraging steel is: C: 0.03wt.%, Mn: 0.5wt.%, Si: 0.8wt.%, P: 0.02wt.%, S: 0.02wt.%, Cr: 22wt.%, Ni: 12wt.%, Mo: 2wt.%, Cu: 0.7wt.%, with the balance being iron; the welding method for welding high-manganese steel and maraging steel is CO2 gas shielded welding.

[0023] In the above embodiments, preferably, the welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

[0024] In the above embodiments, preferably, the external current for CO2 gas shielded welding is 160A and the arc voltage is 20V.

[0025] In the above embodiments, preferably, the high manganese steel and the maraging steel are welded with a Y-shaped bevel; the angle of the Y-shaped bevel is 30°.

[0026] In the above embodiments, the high-manganese steel is further composed of: C: 0.9 wt.%, Si: 0.3 wt.%, Mn: 11 wt.%, P: 0.02 wt.%, S: 0.02 wt.%, with the balance being Fe and unavoidable impurities.

[0027] In the above embodiments, the composition of the martensitic aging steel is further as follows: C: 0.09 wt.%, Ni: 16 wt.%, Co: 0 wt.%, Mo: 4 wt.%, Ti: 0.1 wt.%, with the balance being Fe and unavoidable impurities.

[0028] Example 2:

[0029] A welding method for high-manganese steel and maraging steel, wherein the welding wire composition for welding high-manganese steel and maraging steel is: C: 0.02wt.%, Mn: 1.5wt.%, Si: 0.8wt.%, P: 0.01wt.%, S: 0.01wt.%, Cr: 23.5wt.%, Ni: 13wt.%, Mo: 2.5wt.%, Cu: 0.6wt.%, with the balance being iron; the welding method for welding high-manganese steel and maraging steel is CO2 gas shielded welding.

[0030] In the above embodiments, preferably, the welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

[0031] In the above embodiments, preferably, the external current for CO2 gas shielded welding is 162.5A and the arc voltage is 22V.

[0032] In the above embodiments, preferably, a Y-shaped bevel is formed when the high manganese steel is welded to the martensitic aging steel; the angle of the Y-shaped bevel is 35°.

[0033] In the above embodiments, the high-manganese steel is further composed of: C: 1.05 wt.%, Si: 0.7 wt.%, Mn: 12.5 wt.%, P: 0.02 wt.%, S: 0.02 wt.%, with the balance being Fe and unavoidable impurities.

[0034] In the above embodiments, the composition of the martensitic aging steel is further as follows: C: 0.05 wt.%, Ni: 17 wt.%, Co: 6 wt.%, Mo: 5 wt.%, Ti: 0.55 wt.%, with the balance being Fe and unavoidable impurities.

[0035] Example 3:

[0036] A welding method for high manganese steel and maraging steel, wherein the welding wire composition for welding high manganese steel and maraging steel is: C: 0.02wt.%, Mn: 2wt.%, Si: 0.8wt.%, P: 0.01wt.%, S: 0.01wt.%, Cr: 24wt.%, Ni: 12.5wt.%, Mo: 3wt.%, Cu: 0.5wt.%, with the balance being iron; the welding method for welding high manganese steel and maraging steel is CO2 gas shielded welding.

[0037] In the above embodiments, preferably, the welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

[0038] In the above embodiments, preferably, the external current for CO2 gas shielded welding is 164A and the arc voltage is 23V.

[0039] In the above embodiments, preferably, the high manganese steel and the maraging steel are welded with a Y-shaped bevel; the angle of the Y-shaped bevel is 33.5 degrees.

[0040] In the above embodiments, the high manganese steel is further composed of: C: 1.1 wt.%, Si: 0.6 wt.%, Mn: 13 wt.%, P: 0.02 wt.%, S: 0.02 wt.%, with the balance being Fe and unavoidable impurities.

[0041] In the above embodiments, the composition of the martensitic aging steel is further as follows: C: 0.05 wt.%, Ni: 18 wt.%, Co: 8 wt.%, Mo: 5.5 wt.%, Ti: 0.8 wt.%, with the balance being Fe and unavoidable impurities.

[0042] Example 4:

[0043] A welding method for high-manganese steel and maraging steel, wherein the welding wire composition for welding high-manganese steel and maraging steel is: C: 0.01wt.%, Mn: 2.5wt.%, Si: 0.6wt.%, P: 0.01wt.%, S: 0.01wt.%, Cr: 25wt.%, Ni: 14wt.%, Mo: 3wt.%, Cu: 0.5wt.%, with the balance being iron; the welding method for welding high-manganese steel and maraging steel is CO2 gas shielded welding.

[0044] In the above embodiments, preferably, the welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

[0045] In the above embodiments, preferably, the external current for CO2 gas shielded welding is 165A and the arc voltage is 24V.

[0046] In the above embodiments, preferably, the high manganese steel and the maraging steel are welded with a Y-shaped bevel; the angle of the Y-shaped bevel is 40°.

[0047] In the above embodiments, the high manganese steel is further composed of: C: 1.2 wt.%, Si: 0.8 wt.%, Mn: 14 wt.%, P: 0.01 wt.%, S: 0.01 wt.%, with the balance being Fe and unavoidable impurities.

[0048] In the above embodiments, the composition of the martensitic aging steel is further as follows: C: 0.03 wt.%, Ni: 19 wt.%, Co: 12 wt.%, Mo: 6 wt.%, Ti: 1.0 wt.%, with the balance being Fe and unavoidable impurities.

[0049] The working principle of this invention is as follows: Based on the composition and microstructure characteristics of the two materials, by exploring welding process parameters and selecting suitable welding electrodes and wires, a CO2 gas shielded welding method applicable to both wide-range martensitic aging steel and high-manganese steel was ultimately determined. This method exhibits good welding performance and material composition / microstructure, with no defects in the welded area, and the weld joint strength meets usage requirements.

[0050] As can be seen from the above description, the present invention can obtain the best weld structure by selecting welding rods and wires with suitable compositions and controlling the welding method and welding parameters. The structure has good fusion and is free from welding defects such as cracks, inclusions and porosity. It has good welding performance and material composition, and the weld joint strength reaches more than 500 MPa.

[0051] This invention is the first domestic study on the welding method of high manganese steel and martensitic aging steel, which broadens the application of high manganese steel and martensitic aging steel in more fields.

[0052] The welding process of this invention is easy to operate, requires no preheating before welding, and does not produce cracks even without post-weld treatment. It produces excellent weld structure and properties, which is of great significance for advancing the national "dual carbon" strategic goal.

[0053] The various embodiments in this specification are described in a related manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0054] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A welding method for high-manganese steel and martensitic aging steel, characterized in that: The welding wire composition for welding high manganese steel and maraging steel is: C < 0.04 wt.%, Mn: 0.5–2.5 wt.%, Si < 0.9 wt.%, P: < 0.03 wt.%, S: < 0.03 wt.%, Cr: 22–25 wt.%, Ni: 12–14 wt.%, Mo: 2–3 wt.%, Cu < 0.75 wt.%, with the balance being iron; the welding method for welding high manganese steel and maraging steel is CO2 gas shielded welding.

2. The welding method according to claim 1, characterized in that: The welding wire is a flux-cored welding wire with a diameter of φ1.2mm.

3. The welding method according to claim 1, characterized in that: The external current for CO2 gas shielded welding is 160-165A, and the arc voltage is 20-24V.

4. The welding method according to claim 1, characterized in that: The high-manganese steel is welded to the martensitic aging steel with a Y-shaped bevel; the angle of the Y-shaped bevel is 30° to 40°.

5. The welding method according to claim 1, characterized in that: The composition of the high manganese steel is as follows: C: 0.9-1.2 wt.%, Si: 0.3-0.8 wt.%, Mn: 11-14 wt.%, P: <0.03 wt.%, S: <0.03 wt.%, with the balance being Fe and unavoidable impurities.

6. The welding method according to claim 1, characterized in that: The composition of the martensitic aging steel is: C < 0.1 wt.%, Ni: 16-19 wt.%, Co: 0-12 wt.%, Mo: 4-6 wt.%, Ti: 0.1-1.0 wt.%, with the balance being Fe and unavoidable impurities.

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