Submerged arc welding application modulo null of high intensity Cr-Mo

摘要

PURPOSE:To obtain a weld metal having the excellent toughness and hydrogen cracking resistance characteristic of the weld metal by using a filler wire consisting of a specific compsn. and a specific flux at the time of submerged arc welding of Cr-Mo steels. CONSTITUTION:The wire which contains 0.07wt.% C, =0.30wt.% Si, 0.50 to 1.00wt.% Mn, 2.25 to 3.25wt.% Cr, 0.85 to 1.15wt.% Mo, 0.20 to 0.35wt.% V, =0.03wt.% Nb, =0.02wt.% Ti, =0.60wt.% Ni, and =0.005wt.% and 0.01wt.% N, and consists the balance substantially Fe is used as the filler wire. A high basicity baked flux of an MgO-BaO-SiO2-CaF2 system is used as the flux. Welding is executed under the conditions of 175 to 250 deg.C preheating and inter-pass temp. and 20 to 50 KJ/cm weld heat input.