Welding wire for gas protective welding of reduced activation martensitic/ferritic steel and method of manufacturing the same

Abstract

Welding wire for gas protective welding of reduced activation ferritic/martensitic steel and the manufacturing method, chemical components (weight percentage, wt %): C: 0.10˜0.15, Cr: 8.0˜9.0, W: 1.0˜1.6, V: 0.15˜0.25, Ta: 0.10˜0.17, Mn: 0.50˜0.70, Si: 0˜0.05, N: 0˜0.02, O, Ni, Cu, Al, and Co: 0˜0.01 respectively, P, S, Ag, Mo, and Nb: 0˜0.005 respectively, and balance of Fe. The welding wire has Cr equivalent weight of less than 11, Ni equivalent weight of greater than 3.5. It is manufactured with a wire rod through multi-pass drawing. The rod is subject to annealing heat treatment, tempering treatment performed between the passes of drawing. The annealing process is: the rod is at 940˜1020° C. for 20˜60 minutes, and the n cooled to below 650° C. at rate of less than 45° C./hour, air-cooled to room temperature. The tempering process is: the rod is at 760˜820° C. for 0.5˜2 hours. It reduces forming of δ ferrites in welded joints.