Microstructure evolution in a 3%Co modified P911 heat resistant steel under tempering and creep conditions

▶ MX carbonitrides and M23C6 particles were precipitated in tempered martensite. ▶ Tempered martensite structure was stable during aging. ▶ Crept microstructures lost their martensite morphology in neck portion of sample. ▶ Laths transformed to hot worked substructure in neck portion of crept sample.