EFFECT OF TEMPERATURE AT DUAL PHASE REGION ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF CB400 STEEL

Abstract

In this work, the influence of heat treatment process in the dual phase region of CB400 steel was explored. Calculation results by thermodynamics and JmatPro software determined that temperature of phase transformation is in the range of 730-823^oC for this steel. Analysis of the phase fraction showed that increasing the temperature of the dual phase heat treatment increased the martensitic fraction. With the treatment temperature at 790^oC, the hardness result is 52.4HRC; strength is 960MPa and ductility is 16%. The microstructure shows that the martensite percentage is 25%; the grain of martensite is 8µm; ferrite is 12.5µm.