Work-Hardening and Deformation Mechanism of Cold Rolled Low Carbon Steel

The study reports the mechanical property and microstructure of cold rolled low carbon steel and its work-hardening behavior in the deformation process. The tensile test in room temperature of low carbon steel was implemented for the different cold rolling deformation, the stress-strain curve was draught according to the relationship between strength and deformation and fitted for the polynomial fitting, the strain hardening exponent (n) of test steel was calculated by the Hollomon method. In the whole cold deformation process, the work-hardening of cold rolled steel is significant, work-hardening rate has different degrees decreasewith the deformation increase. The strain hardening exponent is simple and dislocation strengthening is the major cause of hardening processing. The microstructure of test steel was observed after different deformation, the room temperature organization is the ferrite and few pearlite. The original grain is equiaxial and the average grain size is about 23.5 um, and pearlite distributes in ferrite grain boundaries. It was consequently established the cold deformation energy according to dislocation model, the cold deformation energy is main concerned on the plastic deformation to resistance and the initial stress.