A new life extension method for high cycle fatigue using micro-martensitic transformation in an austenitic stainless steel

摘要

Most of the conventional strengthening methods for metals and alloys such as work hardening, precipitation hardening, cause a decrease in ductility and are not very effective for cyclic loading. In this study, a new strengthening method, which is effective for high cycle fatigue, has been developed. The intersections of dislocations in a stainless steel are freezed by very fine martensite particles, which are supposed to suppress dislocation motion at low stress amplitudes. Fatigue life in a high cycle regime increased > 60 times, and no decrease in ductility was observed in tensile tests, as compared to a work-hardened stainless steel.