Gas shield metal core welding wire used for high-strength steel welding based on ULCB structure

Abstract

The invention discloses a gas shield metal core welding wire used for high-strength steel welding based on a ULCB structure. The gas shield metal core welding wire comprises an outer skin and a flux core. The outer skin is composed of a mild-carbon steel strip. By weight,, carbon accounts for 0.025-0.035% of the mild-carbon steel strip is. The width of the steel strip is 10-12mm, and the thickness of the steel strip is 0.6-0.8mm. The flux core comprises, by the weight, 7-12% of manganese, 3-16% of ferrosilicon, 0.5-2% of chromium, 8-14% of nickel, 2-4% of molybdenum, 0.5-3% of zirconium silicon alloy, 0.5-3.5% of fluoride and 0.5-3.5% of ferrotitanium, and the balance is iron power. The filling rate of the flux core is 15-21%. Mixed gas of argon and carbon dioxide is selected as shielding gas for welding, and the carbon dioxide content is 5-20%. The metal core welding wire has good welding technology performance, formed weld joints are beautiful, the strength of deposited metal can reach 800-950MPa, and impact toughness at the low temperature of 40 degrees below zero can reach above 60J.

Description

technical field [0001] The invention belongs to the field of welding in material processing engineering, and in particular relates to a high-strength steel metal-cored welding wire used in argon+carbon dioxide mixed gas shielded welding. Background technique [0002] High-strength ultra-low carbon bainitic (ULCB) steel has excellent strength-toughness matching and good weldability, and has been gradually used in ships, oil pipelines, high-rise buildings, large storage tanks and offshore platforms to replace low-alloy High-strength (HSLA) steel, and mainly used in welded structures. [0003] When welding high-strength steel with a tensile strength of 650-1000MPa and excellent low-temperature toughness, using existing welding consumables, the carbon content of the weld metal is higher than that of the base metal, and the alloying degree of the weld metal is relatively high, and the hardenability is relatively high. Significantly larger than the base metal, cold cracking tends...

AI Technical Summary

Problems solved by technology

[0003] When welding high-strength steel with a tensile strength of 650-1000MPa and excellent low-temperature toughness, using existing welding consumables, the carbon content of the weld metal is higher than that of the base metal, and the alloying degree of the weld metal is relatively high, and the hardenability is relatively high. Significantly larger than the base metal, cold cracking tends to occur in the weld metal

[0004] On the other hand, with the application of high-strength steel in fields such as the West-East Gas Pipeline and offshore oil drilling platforms, low-temperature toughness has become a major challenge for welding work

At present, the gas shielded welding wire with a tensile strength of 900MPa on the market generally has the problem of low impact toughness at -40°C.

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