Fully automatic submerged arc welding solid wire for high manganese steel for lng storage tank

Abstract

The invention discloses a full-automatic submerged-arc welding solid-core welding wire for high-manganese steel for preparing an LNG storage tank. According to the technical scheme, the full-automatic submerged-arc welding solid-core welding wire comprises 0.25-0.45wt% of C, 23-26wt% of Mn, 6-8wt% of Ni, 3-5wt% of W, 0.02-0.04wt% of N, less than or equal to 0.02wt% of P, less than or equal to 0.001wt% of S and the balance of Fe and inevitable impurities. The full-automatic submerged-arc welding solid-core welding wire has the advantages that the price of adopted alloy elements is low, and an alloy component system is simple; and the low-temperature toughness of weld metal formed by the prepared full-automatic submerged-arc welding solid-core welding wire is excellent, the strength of the full-automatic submerged-arc welding solid-core welding wire is matched with the strength of the ultralow-temperature high-manganese steel for preparing the LNG storage tank, and the technical requirements for the strength and the ultralow-temperature toughness of the welded LNG storage tank can be met.

Description

technical field

[0001] The invention belongs to the technical field of fully automatic submerged arc welding solid core wire. Specifically relates to a fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Background technique

[0002] With the vigorous development and application of liquefied petroleum gas (LPG) and liquefied natural gas (LNG), the demand for steel for storage and transportation containers of liquefied petroleum gas (LPG) and liquefied natural gas (LNG) will increase. At present, the low-temperature steel used for LNG storage tanks is 9Ni steel, the working temperature is -196°C, the nickel content is as high as 9%, and the steel plate is expensive. In order to save Ni resources, reduce the cost of steel materials, reduce energy storage and reduce transportation costs, researchers from all over the world are actively developing high-manganese low-temperature steel.

[0003] my country's 13th Five-Y...

Examples

Embodiment 1

[0016] A fully automatic submerged arc welding solid wire for preparing high manganese steel for LNG storage tanks (hereinafter referred to as fully automatic submerged arc welding solid wire). The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.20~0.30wt%, Mn is 23~24wt%, Ni is 7.2~8.0wt%, W is 3.0~3.8wt%, N is 0.02 ~0.03 wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0017] The diameter of the fully automatic submerged arc welding wire is Φ2.4 mm, and the fully automatic submerged arc welding method is used to weld the LNG storage tank; the steel for the LNG storage tank is 25Mn ultra-low temperature steel with a thickness of 20 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 ≥ 4...

Embodiment 2

[0024] A fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Except following, all the other are with embodiment 1:

[0025] The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.30~0.35wt%, Mn is 24~25wt%, Ni is 6.8~7.2wt%, W is 3.8~4.4wt%, N is 0.03 ~0.04wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0026] The microstructure and mechanical properties of the weld metal after welding in this example were detected and analyzed: the weld metal is a fully austenitic structure; there is no solidification crack and reheat crack; the yield strength of the weld metal is 442-488MPa, and the The tensile strength is 652~662MPa, the elongation A=32~34%, and the average value of impact energy at -196°C is A kv =68~77J.

Embodiment 3

[0028] A fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Except following, all the other are with embodiment 1:

[0029] The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.35~0.45wt%, Mn is 25~26wt%, Ni is 6.0~6.8wt%, W is 4.4~5.0wt%, N is 0.03 ~0.04wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0030] 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; no solidification cracks and reheat cracks occur; the yield strength of the weld metal is 488~504MPa, The tensile strength is 662~715MPa, the elongation A=31~32%, and the average value of impact energy at -196°C is A kv =60~68J.

[0031] Compared with the prior art, this specific embodiment has the following positive effects:

[0032] The content of the main alloying element Mn used i...

technical field

[0001] The invention belongs to the technical field of fully automatic submerged arc welding solid core wire. Specifically relates to a fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Background technique

[0002] With the vigorous development and application of liquefied petroleum gas (LPG) and liquefied natural gas (LNG), the demand for steel for storage and transportation containers of liquefied petroleum gas (LPG) and liquefied natural gas (LNG) will increase. At present, the low-temperature steel used for LNG storage tanks is 9Ni steel, the working temperature is -196°C, the nickel content is as high as 9%, and the steel plate is expensive. In order to save Ni resources, reduce the cost of steel materials, reduce energy storage and reduce transportation costs, researchers from all over the world are actively developing high-manganese low-temperature steel.

[0003] my country's 13th Five-Y...

Examples

Embodiment 1

[0016] A fully automatic submerged arc welding solid wire for preparing high manganese steel for LNG storage tanks (hereinafter referred to as fully automatic submerged arc welding solid wire). The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.20~0.30wt%, Mn is 23~24wt%, Ni is 7.2~8.0wt%, W is 3.0~3.8wt%, N is 0.02 ~0.03 wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0017] The diameter of the fully automatic submerged arc welding wire is Φ2.4 mm, and the fully automatic submerged arc welding method is used to weld the LNG storage tank; the steel for the LNG storage tank is 25Mn ultra-low temperature steel with a thickness of 20 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 ≥ 4...

Embodiment 2

[0024] A fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Except following, all the other are with embodiment 1:

[0025] The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.30~0.35wt%, Mn is 24~25wt%, Ni is 6.8~7.2wt%, W is 3.8~4.4wt%, N is 0.03 ~0.04wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0026] The microstructure and mechanical properties of the weld metal after welding in this example were detected and analyzed: the weld metal is a fully austenitic structure; there is no solidification crack and reheat crack; the yield strength of the weld metal is 442-488MPa, and the The tensile strength is 652~662MPa, the elongation A=32~34%, and the average value of impact energy at -196°C is A kv =68~77J.

Embodiment 3

[0028] A fully automatic submerged arc welding solid core wire for preparing high manganese steel for LNG storage tanks. Except following, all the other are with embodiment 1:

[0029] The chemical composition of the fully automatic submerged arc welding solid wire is: C is 0.35~0.45wt%, Mn is 25~26wt%, Ni is 6.0~6.8wt%, W is 4.4~5.0wt%, N is 0.03 ~0.04wt%, P≤0.002wt%, S≤0.001wt%, the balance is Fe and unavoidable impurities.

[0030] 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; no solidification cracks and reheat cracks occur; the yield strength of the weld metal is 488~504MPa, The tensile strength is 662~715MPa, the elongation A=31~32%, and the average value of impact energy at -196°C is A kv =60~68J.

[0031] Compared with the prior art, this specific embodiment has the following positive effects:

[0032] The content of the main alloying element Mn used i...