Predicting The HAZ Toughness Of C And C-Mn Steels: Welding 25mm Plate At 1-7kJ/mm

TWI Industrial Member Report Summary 65/1978

By M F Gittos and R E Dolby

Background

The HAZ toughness of single-pass welds in four 25mm thick C-Mn steels has been determined over the arc energy range 1-7kJ/mm. Two of the steels contained Nb. Toughness was assessed by COD tests using surface-notched and fatigue-cracked specimens and tougt;ness data obtained for coarse-grained, fine-grained, intercritical, and subcritical HAZ regions. The HAZ toughness was very dependent on steel composition and arc energy. A diagram has been constructed which should be helpful in the prediction of the HAZ toughness of C-Mn steels for temperatures down to -60ºC.