TWI Industrial Member Report Summary 482/1993
By A M Barnes
The stringent toughness requirements, now widely placed on weld heat affected zones (HAZs), have enhanced the need for understanding the factors controlling HAZ microstructural development. This is particularly important for those regions, for example the intercritically reheated grain coarsened HAZ, known to frequently exhibit low toughness. In this work, single and dual cycle HAZ thermal simulations were carried out on three steels, forming two compositional pairs differing principally in carbon and manganese. Detailed microstructural examination was undertaken, with particular attention being paid to the microphase decoration that developed on intercritical reheating, and Vickers hardness data were produced; the results were related to the compositional differences and variations in thermal cycling.