Effect of Hot Rolled Deformation on the Microstructure and Mechanical Property of Low Si-Mn-Nb As-hot Dual-Phase Steel

The effect of different deformation on the microstructure and mechanical property of Si-Mn-Nb ashot dual-phase steel were investigated by using TEM,SEM technology and optical microscopy. The results showed that the structure morphology where the island of martensite are dispersed in small ferrite matrix enables hot rolled dual phase steel to obtains comprehensive mechanical properties.With the increase of the deformation,the volume of the second phase increases,but some second-phase particles is serious segregation.The yield strength and tensile strength of hot rolled dual phase steel firstly increase and then drop,yield ratio increased and plasticity decrease.It is found out that the deformation of 92.1% can result in excellent combined mechanical performance with tensile strength achieving an average of 795.66 MPa.