Structural stability of duplex stainless steels
B. Kržan
Kovové materiály 39 (2001) 338–348.
AbstractThe effects of precipitation of intermetallic phases on the microstructure, ferrite content and hardness in 22Cr-5Ni-3Mo-0,15N (wt.%) duplex stainless steel (DSS) have been investigated after ageing heat treatment in the temperature range of 400-800 °C for 30 min, 2, 10, and 100 h. During ageing at 400 and 500 °C, the hardness of the ferrite phase increased. The embrittling reaction, termed "475 °C embrittlement", due to the decomposition of the ferrite phase into a Cr-rich, [alpha]', and Fe-rich, [alpha] was observed. During ageing in the temperature range of 600-800 °C various intermetallic phases precipitated in DDS. The hardness increased and ferrite content decreased with an increase of content of intermetallic phases.
Keywords: duplex stainless steel, intermetallic phases, 475 °C embrittlement, ferrite content