Influência das temperaturas de recozimento contínuo na microestrutura e nas propriedades mecânicas de aço TRIP laminado a frio

Abstract

The influence of intercritical annealing temperature and bainitic isothermal temperature on microstructure and mechanical properties of a cold rolled TRIP steel was studied through continuous annealing simulations. The microstructure was characterized mainly to determine the amount of retained austenite (RA) while the mechanical behavior was assessed by means of tensile tests. Significant changes were observed in the final microstructure,mainly in the RA volume fraction and its carbon content. The best combinations of high mechanical strength and good ductility were obtained at the soaking temperatures of 800°C and 820°C and the bainitic isothermal transformation temperature of 410°C. The use of these combinations resulted in a RA fraction of approximately 15% with a mechanical stability that allows a gradual transformation of part of this RA during deformation.