WELD METAL AND WELDED STRUCTURE

摘要

This welded structure comprises a weld metal which contains C, Si, Mn, Cr, Mo, V, Nb, N and O in prescribed amounts respectively with the balance being Fe and unavoidable impurities and which exhibits an A value of 200 or more and a Z value of 0.05 or more. The A value is calculated from the element contents of the weld metal according to the formula: A value = ([V]/51 + [Nb]/93)/ {[V] × ([Cr]/5 + [Mo]/2)} × 10 4 . The Z value is calculated according to the formula: Z value = N × [insol. V] [wherein N (particles/µm) is the number density of carbide particles present in a prior austenite grain boundary per unit grain boundary in the stress-relief annealed weld metal, and [insol. V] is the concentration of compound-type V as determined by analyzing an extraction residue of the stress-relief annealed weld metal].