Mechanical Behavior of Deformation-Induced α′-Martensite and Flow Curve Modeling of a Cast CrMnNi TRIP-Steel

For the modeling of the mechanical behavior of a two phase alloy with the rule of mixture (RM), the flow stress of both phases is needed. In order to obtain these information for the a'-martensite in high alloyed TRIP-steels, compression tests at cryogenic temperatures were performed to create a fully deformation-induced martensitic microstructure. This martensitic material condition was subsequently tested under compressive loading at -60, 20, and 100 degrees C and at strain rates of 10-3, 100, and 103?s-1 to determine the mechanical properties. The a'-martensite possesses high strength and surprisingly good ductility up to 60% of compressive strain. Using the flow stress behavior of the a'-martensite and that of the stable austenitic steel AISI 316L, the flow stress behavior of the high alloyed CrMnNi TRIP-steel is modeled successfully using a special RM proposed by Narutani et al.