An investigation of the hydrogen-induced cracking behaviours during welding of two high strength structural steels

TWI Industrial Member Report Summary 507/1995

D J Abson

Background

The weldability of two newly-developed C-Mn-Al-B steels, with yield strengths 2550 and 2690MPa, and plate thicknesses of 60 and 50mm, respectively, is being assessed. The preheat levels required to avoid HAZ hydrogen-induced cracking during welding in CTS tests are at least 50°C lower than those predicted by the nomograms in BS 5135:1984. In submerged-arc butt welds deposited with three different fluxes, the preheat levels employed have been compared with predictions for avoidance of both weld metal and HAZ hydrogen-induced cracking. The weld metal behaviour was consistent with recent TWI predictions for avoidance of weld metal cracking.