Welding low-alloy steels containing niobium - titanium and-or vanadium added to weld for improved toughness

摘要

When fusion welding steel contg. =0.02% Nb there is introduced into the molten weld metal one or both of Ti and V to produce a residual concentration in the solifidied bead which is related to the mobium content by the formula 2.5 (%Ti) + 0.4 (%V)= 0.5 to 2 (%Nb). The additive metal may be applied as a weld filler metal, as a component of a consumable electrode, or by locating it in elemental form in the joint area for melting. Pref. the weld deposit contains by wt. 0.5-3% Mn, 0.1-1.5% Mo, 0.02-0.15% C, up to 3% Ni, up to 0.6% Cu, up to 0.6% Si, =1% Cr, =0.05% P, =0.03% S, 0.01-0.12% Nb and Ti/V, balance Fe. The process is applied particularly to welding pipe lines.