TWI Industrial Member Report Summary 15/1976
By M F Gittos and R E Dolby
The toughness of coarse grained heat-affected zone (HAZ) regions of various 25mm thick C and C-Mn steels has been assessed by crack opening displacement (COD) tests after welding at 2kJ/mm. The test specimen design was chosen to reproduce the situation of shallow cracks at the toes of fillet and butt welds. Correlations have been explored between toughness, composition and microstructure and a diagram proposed for assessing critical COD values as a function of carbon equivalent. The effect of ageing on HAZ toughness was examined.