Simulated heat affected zone in ASTM A533-B steel plates under low heat inputs

To investigate the weldability of A533-B steel plates, simulations of the coarse grained region of heat affected zone (with heat inputs of 10, 20 and 30 kJ cm−1) followed by inter-pass heating at 300 °C and post-weld heat treatments at 590 °C were carried out. The microstructural evolution, the hardness and the toughness of the simulated heat-affected zone were studied. With heat inputs of 10 and 20 kJ cm−1, both of the simulated microstructures contain mixtures of lower bainite and auto-tempered martensite. With heat input of 30 kJ cm−1, the simulated microstructure is composed mainly of lower bainite. The Charpy impact toughness has also been measured for the simulated heat input specimens, which were treated by inter-pass heating at 300 °C and post-weld treatment at 590 °C.