High-toughness gas protective welding wire for low alloy high-strength steel

Abstract

The chemical composition of high-toughness gas shielded welding wire for low alloy high-strength steel contains (wt%): C 0.05-0.12, Mn 1.20-2.00, Ni 0.60-1.60, Si 0.30-1.20, Cu 0.10-0.50, Cu 0.10-0.60, Ti 0.10-0.20, B 0.02-0.010, S is less than or equal to 0.10, P is less than or equal to 0.20 and the rest is Fe and inevitable impurity elements. When said welding wire is used to make mixed gas (80% Ar+20% Co2) shielded arc welding the weld metal tensile strength is 700-800 MPa, and the persuccion power at -30 deg.C Akv is greater than or equal to 80J. Said invented with is applicable to gas shielded arc welding for 700 MPa low-alloy high-strength steel, and possesses good technological performance and is suitable for welding all positions.

Description

technical field [0001] The invention relates to a high-toughness gas-shielded welding wire for low-alloy high-strength steel, which belongs to the field of welding materials. This welding wire uses mixed gas (80% Ar+20% CO 2 ) during shielded welding, the tensile strength of the weld metal is 700-800MPa, and the impact energy at -30°C is A kv ≥80J. Background technique [0002] At present, the usage of gas shielded welding wire has accounted for 31% of the output of welding materials in the United States, about 41% in Japan, about 56% in Western Europe, and only 10% of the total welding materials in China. There is no mature 700MPa gas in China. Shielded welding commodity welding wire, and a single variety, is far from meeting the growing demand for gas-shielded welding of low-alloy high-strength steel. The low-matching Mn-Si series welding wire ER70S-6 is generally used in China. The disadvantage is that the tensile strength of the weld metal of the welding wire is lower...

AI Technical Summary

Problems solved by technology

[0002] At present, the usage of gas shielded welding wire has accounted for 31% of the output of welding materials in the United States, about 41% in Japan, about 56% in Western Europe, and only 10% of the total welding materials in China. There is no mature 700MPa gas in China. Shielded welding commodity welding wire, and the variety is single, far from meeting the growing demand for gas shielded welding of low-alloy high-strength steel

The low-matching Mn-Si series welding wire ER70S-6 is generally used in China. The disadvantage is that the tensile strength of the weld metal of the welding wire is lower than 600MPa, and the low-temperature impact toughness is poor.

The ST700 mixed gas shielded welding wire produced by ESAB has reached 700MPa in the tensile strength of the deposited metal, but its shortcoming is that the impact toughness cannot meet the requirements of the structure in low temperature service.

In 2000, Nippon Steel Corporation of Japan applied for the "Welding wire for pipeline gas shielded welding and gas shielded welding method for pipeline circular seam", patent application number JP2000218391 A. The weld metal of the gas shielded welding wire introduced has good low temperature impact toughness, but The disadvantage is that the tensile strength cannot reach 700MPa stably