Electron beam welding method for obtaining weld metal with excellent low temperature toughness

摘要

PROBLEM TO BE SOLVED: To provide a welding method by stably making the micro structure of a weld metal an acicular ferrite and obtaining a high toughness weld metal in the case of welding by a laser beam or an electron beam. SOLUTION: In a laser beam or electron beam welding method to weld a steel material having a composition consisting of, by weight, 0.01-0.15% C, 0.01-1.5% Si, 0.2-2% Mn, =0.03% P, =0.03% S, 0.0005-0.1% Al, 0.001-0.1% Ti, and the balance Fe with inevitable impurities, further, satisfying a formula :0.05(% C + % S + % Mn + % Cr + % Cr/20 + % Ni/60 + % Mo/15 + % V/10 + 5% B + % Cu/20)0.2, at least one of welded faces facing at a welding part is a scale deposition face.