Self-protection flux-cored wire suitable for ultralow-temperature high manganese steel

Abstract

The invention relates to a self-protection flux-cored wire suitable for ultralow-temperature high manganese steel. According to the technical scheme, the self-protection flux-cored wire is composed of a carbon steel strip, a single-strand alloy welding wire and flux-cored powder. The carbon steel strip comprises the following chemical components: 0.03-0.05 wt% of C, 0.05-0.08 wt% of Si, 0.5-0.8 wt% of Mn, less than or equal to 0.005 wt% of P, less than or equal to 0.005 wt% of S and the balance of Fe. The single-strand alloy welding wire comprises the following chemical components: 0.3-0.6 wt% of C, 0.05-0.2 wt% of Si, 24-33 wt% of Mn, less than or equal to 0.003 wt% of P, less than or equal to 0.003 wt% of S and 4-7 wt% of Ni. The flux core powder comprises the following chemical components in percentage by weight: 40 to 50 percent of barium fluoride, 10 to 17 percent of rutile, 4 to 7 percent of aluminum powder and 2 to 6 percent of sodium fluoroaluminate. Among the three chemical components, the balance is Fe and inevitable impurities. Weld metal formed by the self-protection flux-cored wire suitable for the ultralow-temperature high-manganese steel has the characteristic of high toughness under the ultralow-temperature service condition, and the strength of the weld metal is matched with that of the ultralow-temperature high-manganese steel.

Description

technical field [0001] The invention belongs to the technical field of flux-cored welding wire suitable for ultra-low temperature high manganese steel. It specifically relates to a self-shielding flux-cored welding wire suitable for ultra-low temperature high manganese steel. Background technique [0002] Ultra-low temperature high manganese steel is based on the C-Mn-Cr main component system to obtain a highly stable austenite structure, with high elongation, low yield ratio, excellent low temperature performance at -196°C, non-magnetic and low welding costs, etc. , is a cutting-edge material for low-temperature service environments, and is expected to be widely used in liquid cargo tanks of LNG carriers, fuel tanks of LNG fuel ships, etc., and can realize Ni-reduced steel plates and greatly reduce construction costs. [0003] Existing self-shielded flux-cored wire technology for ultra-low temperature high manganese steel has a problem of insufficient toughness, such as th...

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Problems solved by technology

[0003] Existing self-shielded cored wire technology for ultra-low temperature high manganese steel has a problem of insufficient toughness, such as the patented technology of "a self-shielded flux cored wire for ultra-low temperature high manganese steel" (CN112894198A), the problem of this technology is The impact toughness is insufficient (the impact energy at -196°C is 60~90J), while the impact toughness of the ultra-low temperature high manganese steel base plate is relatively high (the impact at -196°C is about 200J), the two do not match, and the welding performance is difficult to meet for -196 The technical requirements for the strength and ultra-low temperature toughness of LNG storage tanks at operating temperatures of ℃, which will seriously affect the safety of the tank body