Effects of PWHT on Microstructure and Mechanical Properties of A516 Gr.70

Abstract

The article describes the effect of simulated post weld heat treatment (PWHT) on the properties and microstructure of high performance pressure vessel steel plate A516 Gr.70. The research indicates that the strength decreased sharply and the toughness is decreased slightly with increasing simulated PWHT times. And the strength of plate with high carbon content decrease more than which with low carbon content. The main reason of strength decrease is the ferrite degenerated after simulated PWHT. However, the strength can still satisfy the standard requirement with the reasonable composition design.