The Relationships between the Transformation Characteristics and the Fracture and Fatigue Properties of TRIP Steels and Other Metastable Austenitic Steels.

摘要

The present study was aimed at obtaining further information on the inter-relationship between the microstructural, composition, and the mechanical variables. Of particular interest were the stress-strain-martensite relations for various strain rates, the effect of stress state on these relationships and the kinetics of martensite formation under fatigue conditions. Unfortunately, TRIP steel was only available in wire form. Thus only the uniaxial tensile tests and the rotating beam fatigue tests were conducted on this material. The effects of strain rate on tensile strength and elongation for TRIP steel wires were determined by the manufacturer and are also reported here (Appendix). To obtain the effect of stress state on the strain-martensite-ductility relationships in metastable austenitic alloys, tests were conducted on type 301 stainless steel and on AM-355 CRT steel. While these steels do not achieve the strength level of TRIP steels, it is believed that the results can be used as a guide to estimate the stress state effects on TRIP steel.