MIG/MAG welding wire for -196°C working temperature

Abstract

The invention relates to a melting electrode gas shielded welding wire suitable for the working temperature of -196°C. The technical solution is: the chemical composition of the metal gas shielded welding wire is: C is 0.30~0.55wt%, Mn is 24~26wt%, Ni is 6.4~8.2wt%, W is 2.5~4.0wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities. The invention has low preparation cost and simple alloy composition system; the formed weld metal has the characteristics of ultra-low temperature and high toughness, its strength matches that of ultra-low temperature high manganese steel, and the welded joint has high strength and excellent mechanical properties of ultra-low temperature toughness, which can meet the requirements of Specifications for strength and cryogenic toughness of devices to be welded at ‑196°C.

Description

technical field

[0001] The invention belongs to the technical field of MIG shielded welding wire. In particular, it relates to a melting electrode gas shielded welding wire suitable for the working temperature of -196°C. Background technique

[0002] Containers suitable for working at -196°C mainly refer to storage and transportation containers such as liquefied natural gas (LNG). At present, the steel used for LNG storage tanks is 9Ni steel for commercial use. Because the nickel content is as high as 9%, the steel plate is expensive. In order to save Ni resources, reduce the cost of steel materials and energy storage and transportation costs, researchers from all over the world are actively developing ultra-low temperature high manganese steel.

[0003] In our country, some universities and iron and steel enterprises have taken the lead in carrying out some theoretical and experimental research jointly, and developed ultra-low temperature high manganese steel suitable for...

Examples

Embodiment 1

[0016] A metal gas shielded welding wire suitable for -196°C working temperature (hereinafter referred to as metal gas shielded welding wire). The chemical composition of the metal gas shielded welding wire is: C is 0.30~0.38wt%, Mn is 25.3~26.0wt%, Ni is 6.4~7.0wt%, W is 2.5~3.0wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0017] The metal gas metal shielded welding wire has a diameter of Φ1.2 mm, and the metal gas metal shielded welding welding method is used to weld 25Mn ultra-low temperature steel with a thickness of 16 mm.

[0018] The chemical composition of the 25Mn ultra-low temperature steel is: C is ≤0.40~0.50wt%, Si is 0.10~0.20wt%, Mn is 20~28wt%, N is 0.01~0.08wt%, P is ≤0.005wt%, S is ≤0.003wt%. The mechanical properties of the 25Mn ultra-low temperature steel are: tensile strength ≥ 400MPa, yield strength ≥ 560MPa, elongation A=40%; impact energy A at -196°C kv ≥54J.

[0019] The groove type of the test plate of the 25Mn ultra...

Embodiment 2

[0025] A metal gas shielded welding wire suitable for -196°C working temperature. Except following, all the other are with embodiment 1:

[0026] The chemical composition of the metal gas shielded welding wire is: C is 0.38~0.45wt%, Mn is 24.7~25.3wt%, Ni is 7.0~7.6wt%, W is 3.0~3.5wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0027] The diameter of the metal gas shielded welding wire is Φ1.2mm.

[0028] Detect and analyze the microstructure and mechanical properties of the weld metal after welding in this example: the weld metal is a fully austenitic structure; there are no solidification cracks and reheat cracks; the yield strength of the weld metal is 456~478MPa, The tensile strength is 663~695MPa, the elongation A=38~39%, and the average value of impact energy at -196°C is A kv =74~82J.

Embodiment 3

[0030] A metal gas shielded welding wire suitable for -196°C working temperature. Except following, all the other are with embodiment 1:

[0031] The chemical composition of the metal gas shielded welding wire is: C is 0.45~0.55wt%, Mn is 24.0~24.7wt%, Ni is 7.6~8.2wt%, W is 3.5~4.0wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0032] The diameter of the metal gas shielded welding wire described in this embodiment is Φ1.2mm.

[0033] The microstructure and mechanical properties of the weld metal after welding in this example were tested and analyzed: the weld metal is a fully austenitic structure; there are no solidification cracks and reheat cracks; the yield strength of the weld metal is 410~425MPa, The tensile strength is 582~625MPa, the elongation A=41~42%, and the average value of impact energy at -196°C is A kv =95~106J.

[0034] Compared with the prior art, this specific embodiment has the following positive effects:

[0035] The cont...

technical field

[0001] The invention belongs to the technical field of MIG shielded welding wire. In particular, it relates to a melting electrode gas shielded welding wire suitable for the working temperature of -196°C. Background technique

[0002] Containers suitable for working at -196°C mainly refer to storage and transportation containers such as liquefied natural gas (LNG). At present, the steel used for LNG storage tanks is 9Ni steel for commercial use. Because the nickel content is as high as 9%, the steel plate is expensive. In order to save Ni resources, reduce the cost of steel materials and energy storage and transportation costs, researchers from all over the world are actively developing ultra-low temperature high manganese steel.

[0003] In our country, some universities and iron and steel enterprises have taken the lead in carrying out some theoretical and experimental research jointly, and developed ultra-low temperature high manganese steel suitable for...

Examples

Embodiment 1

[0016] A metal gas shielded welding wire suitable for -196°C working temperature (hereinafter referred to as metal gas shielded welding wire). The chemical composition of the metal gas shielded welding wire is: C is 0.30~0.38wt%, Mn is 25.3~26.0wt%, Ni is 6.4~7.0wt%, W is 2.5~3.0wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0017] The metal gas metal shielded welding wire has a diameter of Φ1.2 mm, and the metal gas metal shielded welding welding method is used to weld 25Mn ultra-low temperature steel with a thickness of 16 mm.

[0018] The chemical composition of the 25Mn ultra-low temperature steel is: C is ≤0.40~0.50wt%, Si is 0.10~0.20wt%, Mn is 20~28wt%, N is 0.01~0.08wt%, P is ≤0.005wt%, S is ≤0.003wt%. The mechanical properties of the 25Mn ultra-low temperature steel are: tensile strength ≥ 400MPa, yield strength ≥ 560MPa, elongation A=40%; impact energy A at -196°C kv ≥54J.

[0019] The groove type of the test plate of the 25Mn ultra...

Embodiment 2

[0025] A metal gas shielded welding wire suitable for -196°C working temperature. Except following, all the other are with embodiment 1:

[0026] The chemical composition of the metal gas shielded welding wire is: C is 0.38~0.45wt%, Mn is 24.7~25.3wt%, Ni is 7.0~7.6wt%, W is 3.0~3.5wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0027] The diameter of the metal gas shielded welding wire is Φ1.2mm.

[0028] Detect and analyze the microstructure and mechanical properties of the weld metal after welding in this example: the weld metal is a fully austenitic structure; there are no solidification cracks and reheat cracks; the yield strength of the weld metal is 456~478MPa, The tensile strength is 663~695MPa, the elongation A=38~39%, and the average value of impact energy at -196°C is A kv =74~82J.

Embodiment 3

[0030] A metal gas shielded welding wire suitable for -196°C working temperature. Except following, all the other are with embodiment 1:

[0031] The chemical composition of the metal gas shielded welding wire is: C is 0.45~0.55wt%, Mn is 24.0~24.7wt%, Ni is 7.6~8.2wt%, W is 3.5~4.0wt%, P≤0.002wt %, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0032] The diameter of the metal gas shielded welding wire described in this embodiment is Φ1.2mm.

[0033] The microstructure and mechanical properties of the weld metal after welding in this example were tested and analyzed: the weld metal is a fully austenitic structure; there are no solidification cracks and reheat cracks; the yield strength of the weld metal is 410~425MPa, The tensile strength is 582~625MPa, the elongation A=41~42%, and the average value of impact energy at -196°C is A kv =95~106J.

[0034] Compared with the prior art, this specific embodiment has the following positive effects:

[0035] The cont...