Discussion on the heat treatment process of cold rolled Q345 steel in laboratory

A new kind of DP steel with about 40% martensite in matrix was developed from cold rolled Q345 steel by continuous annealing simulation.Microstructure and mechanical properties obtained by conventional heat treatment certified that the microstructure matrix is composed of ferrite,pearlite and martensite,the samples exhibited high tensile strength and low yield ratio,however,the elongation is very low,only about 10%.Due to the high carbon content,low soaking temperature and relatively higher rapid cooling start temperature should be adopted for the new process.