Effects on Microstructure and Mechanical Properties of the Cold Rolled Low Carbon Steel During Annealing

The strip steel was cold rolled by conventional multi-pass cold rolling. The sample with original thickness of 2.5 mm was cold rolled to 0.4 mm with reduction of 84%. Then the effect of annealing time and temperature on the microstructure and mechanical property were investigated after the specimens were annealed at different temperature for same annealing time. The results show that the mechanical properties and microstructure of the cold rolled strip steel after annealing were associated with the annealing regime. The grains were elongated significantly and high density dislocation was observed in the strip steel after cold rolling. With increasing of the annealing temperature, high density dislocation and smaller subgrains were observed in the strip steel. It was indicated that the average grain size, dislocation density, on the contrary, the number of subgrain increase. Mechanical properties were also assessed by taking the annealing characteristics of the cold rolled low carbon steel into consideration.