Welding wire and method for welding fire-resistant steel with yield strength of 420MPa grade through welding wire

Abstract

The invention discloses a welding wire and a method for welding fire-resistant steel with the yield strength of 420MPa grade through the welding wire. The welding wire is prepared from, by mass, 0.01-0.14% of C, 0.10-0.40% of Si, 1.00-1.60% of Mn, 0.20-0.60% of Ni, 0.05-0.20% of Mo, 0.01-0.05% of Ti, 0.0005-0.002% of B, 0.05-0.15% of Nb, 0.02-0.08% of Al, 0.01-0.09% of V, 0.001-0.005% of N, and the balance Fe and unavoidable impurity elements. After welding is performed, the formed deposited metal and welded joint have excellent comprehensive mechanical properties, high high-temperature tensile property and high low-temperature impact energy. The welding wire adopts low-Mo component design, and has lower production cost with the same performance.

Description

technical field [0001] The invention belongs to the technical field of welding materials, and in particular relates to a gas-shielded welding wire for refractory steel with a yield strength of 420MPa and a welding method thereof. Background technique [0002] With the rapid development of large buildings, factors such as safety, economy, beautiful appearance, and space utilization have been widely concerned by people. As a new type of steel material, fire-resistant steel has quickly become the first choice for large-scale building structures around the world due to its advantages of high strength, light weight, fire resistance, earthquake resistance, and no pollution compared to fire-resistant coatings. [0003] Refractory steel not only requires high room temperature performance, but also requires high low temperature impact toughness and high temperature strength. Since the building structure will inevitably bear the impact, high temperature, and distortion caused by eart...

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Problems solved by technology

[0005] Refractory steel welding wire for building structures generally adopts a high-Mo design method to achieve its high-temperature strength. For example, the welding wire components disclosed in the invention patent applications of CN108857140A and CN108941972A all add 0.20% to 0.59% Mo element; Publication No. The invention patent application of CN108788518A discloses that 0.60%~1.00% Mo element is added in the gas shielded welding wire; the invention patent application whose publication number is CN102717206 adds 0.25%~0.60% Mo element; A large amount of Mo element is added to achieve excellent high-temperature tensile strength, but the addition of a large amount of Mo element will inevitably greatly increase the cost of the material.

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