scope:

The objectives of the work described in this WRC Bulletin were

(1) to develop data on HAZ impact toughness and hardness under various metallurgical conditions, including various vanadium and columbium contents, low and high welding inputs, and various PWHT conditions;

(2) to identify the specific microstructural details that can lead to significant changes in the HAZ toughness and hardness, especially the effects of vanadium and columbium additions, welding heat inputs, and PWHT; and

(3) to investigate the fracture mechanism in a multipass HAZ, including crack initiation and propagation, and the mechanical and microstructural aspects controlling the fracture process. The investigation has led to a better understanding of the detrimental effect that the addition of microalloy vanadium and columbium has on the impact toughness of the multipass HAZ of C-Mn steels. Publication of this document - WRC Bulletin No. 395 was sponsored by the Pressure Vessel Research Council