Improvements in the corrosion resistance of PM stainless steels

Analytical models of the diffusion controlled pearlite-to-austenite transformation during isothermal and uniform heating processes are presented. The solute elements diffusing through the volume of austenite and the interfaces between austenite and pearlite were both considered synchronously. The austenite formation from pearlite of a Fe-1C-1.44Cr steel was calculated with the present model and the results were compared to the experimental results. Calculation results show that the transformation is Cr diffusion-controlled and C diffusion-controlled below and above the transition temperature of austenite growth (so called PNTT), respectively. The theory about PNTT is quantitatively proved to be right.