INFLUENCE OF DEFORMATION AND ISOTHERMAL QUENCHING TEMPERATURE ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ADVANCED HIGH STRENGTH STEEL - DP600

Abstract

The article presents the research results on the effect of deformation and iso-thermal quenching temperature on the microstructure and mechanical properties of DP600 steel. By analytical results of structure such as optical microscopy; XRD and SEM have identified the microstructure of this steel. In addition, by analysis of the phase fraction, the bainite phase ratio which was determined during heat treatment at 400^oC with a 40% deformation was 48%. The microstructure has determined the distribution of bainite; ferrite and residual austenite in the structure of this steel. With this process, the austenite temperature is 800^oC for 30 minutes and the isothermal quenching at 400^oC for 30 minutes gives the highest hardness value of 56,2HRC and the strength limit is 1083MPa; elongation was 46.82%.