RESEARCH ABOUT PHASE TRANSFORMATION OF LOW CARBON STEEL WHEN DEFORMATION AND HEAT TREATMENT

In this paper, the influence of cold rolling with 70% and heat treatment on the microstructure of a 0.22C-1.4Mn-1.6Si TBF steel was investigated. The results show that, when the cold rolling and heat treatment, the microstructures were changed (the finer grain size ferrite was obtained, the solid phases were homogeneously distributing and especially the austenite fraction was 16% after this process), therefore, the mechanical properties were increased. According to this process, the ferrite grain size decreases to less than 6.4μm and the austenite phase reaches to 16%, hence, the high strength and good ductility of this steel were obtained (the strength is up to 800 MPa and the elongation is up to 35%)..