Effect of<i>δ</i>ferrite solidification morphology of austenitic stainless steel weld metal on properties of welded joints

Abstract

Summary The properties of austenitic stainless steel weld metals are strongly influenced by the appearance in the microstructure of δ ferrite of a given morphology. Susceptibility to hot cracking and low temperature toughness are strongly influenced by the complex austenitic‐ferritic structures which may develop, depending on steel chemical composition and deposit cooling rate. The latest research on this issue highlights the importance of ‘solidification mode’ as regards the influence on the appearance of δ ferrite with a certain morphology. In fact, it is very important to understand the solidification sequence, the possible primary solidification modes and the subsequent solid state transformations, in order to correlate the structural components of the weld metal with, on the one hand, welding process parameters and on the other, the properties of welded joints.