Refinement of trip steel microstructure by incremental deformation

Abstract

TRIP steels represent a modern group of low alloyed steels offering a potential for excellent combination of strength and ductility. Unconventional forming methods employing the TRIP effect at final cold forming operation require not only very fine structure but also appropriate combination of phases in these steels. The microstructure development can be controlled by appropriate temperature interval and amount of incremental deformation. In this study, the influence of various temperature ranges and strain magnitudes in 20-step deformation schedule on grain refinement was investigated. Suitable parameters of the schedule led to ferrite-bainite microstructure with 15% retained austenite, ferrite grain size of about 2 um and elongation of about 30%.