Critical factors governing the thermal stability of austenite in an ultra-fined grained Medium-Mn steel

摘要

The time-evolution of retained austenite at 650 degrees C is shown to be a fair indicator of the factors governing the austenite stability. The grain size contribution to austenite stability is evidenced and a martensite start temperature (M-s) law applicable to medium-Mn steels and including both the chemical and size effects is determined.