Abstract
Duplex stainless steels are characterized by favorable combination of mechanical and corrosion properties, consisting roughly of equal parts of austenite ({gamma}) and ferrite ({alpha}). But exposure to elevated temperatures brings partial decomposition of ferrite to austenite and sigma phase, which deteriorates their properties. Sigma phase forms often at ferrite/austenite ({alpha}/{gamma}) interfaces through nucleation process. The heterogeneous nucleation of sigma phase at an {alpha}/{gamma} interface depends on the chemical driving force and the interfacial energy. Many studies have examined the effect of chemical driving force on sigma phase formation in duplex and austenitic stainless steel weld metals with different chemical compositions, but no detailed report has described the influence of {alpha}/{gamma} interfacial energy on sigma phase nucleation. The Kurdjumov-Sachs (K-S) orientation relationship is accepted to bring a coherent and low energy {alpha}/{gamma} interface in duplex stainless steels. The coherency of {alpha}/{gamma} interface can affect the sigma phase formation. The present study has examined the effect of crystallographic orientation relationship at {alpha}/{gamma} interface on sigma phase formation in a duplex stainless steel weld metal where the chemical element distribution is relatively uniform because of rapid cooling during weld thermal cycle.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call