WELDING PROCEDURE FOR B-CONTAINING CRMOV CAST STEEL

摘要

PURPOSE:To provide the prevention of the embrittleness of a heat affected zone, etc. by welding a B-contg. CrMoV cast steel contg. specific weight % each of B, Cr, Mo and V by a CrMoV steel filler metal contg. prescribed % each of Cr, Mo and V then subjecting the steel to a heat treatment. CONSTITUTION:The B-contg. CrMoV cast steel contg. 0.0005-0.005% B, 0.5-2% Cr, 0.5-2% Mo and 0.1-0.5% V is welded by the filler metal of the CrMoV steel contg. 0.2-1% Cr, 0.5-2% Mo and 0.1-0.5% V. The steel is subjected to the heat treatment for annealing at 1,000-1,100 deg.C and tempering at 650-750 deg.C after welding. The generation of the hardness peak at the boundary between the base metal and the weld metal is prevented and the embrittleness is prevented by the above-mentioned method. The creep strength of the deposited metal for a Larson-Miller parameter P is improved as shown by a solid line.