In-situ simultaneous SANS and diffraction measurements to unravel controlling mechanisms of delayed phase separation in stainless steels

Duplex stainless steels, containing approximately equal amounts of two different phases (ferrite and austenite) are used in various demanding industries that require excellent corrosion and mechanical properties such as nuclear or gas industry. However, they are prone to embrittlement when exposed to elevated temperatures for a prolonged time, which limits the applications and the lifetime of components. This is linked with so-called phase separation that occurs in ferrite. It has been observed that this embrittlement can be delayed by different heat treatments, but the mechanisms that lie behind this delay are still unknown. By analysis of the phase separation in-situ (while performing the different heat treatments), we can separate different potential mechanisms for this delay and increase our understanding, which will help us to control phase separation in the future.