Microstructural evolution in a PH13-8 stainless steel after ageing Original Research Article

The precipitation process in a wrought PH13-8 steel during ageing was investigated using a position sensitive atom probe. The precipitates formed are enriched in Ni and Al, and depleted of Fe and Cr, yet the composition is far from the stoichiometric NiAl phase. They may take on different shapes at different temperatures. The hardening effects observed during early stages of ageing should be due to the redistribution of atoms such as Fe, Cr, Ni, and/or Al. Particle coarsening takes place simultaneously with the development of the composition of the NiAl-enriched precipitates. Mo segregation at the precipitate/matrix interface was not found.