1200MPa grade ultra-high strength gas shielded solid welding wire and its production process

Abstract

The invention relates to a 1200MPa-level ultra-high-strength gas-shielded solid welding wire and a production process thereof. The welding wire adopts an optimized alloy ratio of low carbon, Si, Mn, Ni, Cr and Mo to improve the strength of the weld, combines Nb, Ti and V multi-element microalloying, and utilizes solid solution strengthening, fine grain strengthening and precipitation strengthening to ensure the plastic toughness of the weld. When the welding wire is produced through smelting, forging, rolling, drawing, heat treatment and copper plating processes, vacuum induction and electroslag remelting are adopted to control the contents of P, S, O and N to be below 100ppm, the forging blank has uniform quality, the rolling structure is dense, the grains are refined, the stress is eliminated and the structure is improved after annealing, and copper plating protection is performed after drawing. The tensile strength of the weld metal of the welding wire is ≥1200MPa, and the impact toughness at -40℃ is ≥27J. Compared with the existing 90-level welding wire, the invention takes into account the toughness and significantly improves the welding strength at the same time, can give full play to the advantages of high-strength steel, and meet the welding application requirements of 1300MPa high-strength steel.

Images