Improving weld bead toughness - by hot deforming to flatten bead

摘要

Directly after welding by gas protected or submerged arc welding, the bead is deformed whilst its central temp. is 600-950 (pref. 700-850 degrees C) in one or several steps by up to 50 (pref. 10-30)%. The bead is flattened or in the case of fillet or build-up welding a concave shape is produced. Deformation is effected by rolling forging, drawing or processing. The weld produce in molten state but prior to mixing with the base material pref. comprises 0.03-0.06% C; 0.3-0.45% Si; 1.6-2.0% Mn; 0.02% P; 0.02% S; and one or more of 1.5% Mo, 0.06% Nb; 0.2% V and 0.03% N2. The weld has better strength, toughness and improved notch impact transition temp.