Phosphorus effects on microstructural evolution and phase stability in type 316 Ti stainless steels

The influence of phosphorus on microstructural evolution and phase stability in type 316 Ti stainless steels has been found to be significant during high temperature exposure. Ageing of type 316 Ti + P steels in the temperature range 600–800°C for times up to 4000 h has been found to result in an abundant precipitation of carbide phases followed by the formation of intermetallic compounds. This study shows that the presence of phosphorus noticeably changes the precipitation behaviour in type 316 Ti stainless steels. However, a partial redissolution of some precipitate phases has been found to occur for long time treatments at 800°C.