Microstructural development and solidification cracking susceptibility of austenitic stainless steel welds

The microstructures of austenitic stainless steel welds typically contain a variety of complex austenite-ferrite structures. These structures are a result of both the solidification behaviour and subsequent solid state transformations which are controlled by both composition and weld cooling rates. The solidification cracking susceptibility is directly related, in a complex fashion, to the solidifying weld structure. The solidification and solid state transformations which occur during welding are reviewed in detail and this behaviour is related to solidification cracking susceptibility. Improved understanding of these phenomena offers an opportunity to improve commercial applications of austenitic stainless steels.