Effects of Annealing and Coiling Temperature on Microstructure and Properties of 590 MPa Cold Rolling Hot Dip Galvanizing Dual Phase Steel Plates

590 MPa cold rolling hot dip galvanizing dual phase steel plates were prepared in laboratory.Effects of coiling temperature and annealing temperature on microstructure and mechanical properties of the plates were studied by means of SEM,TEM and tensile experiments.The results indicate that after annealing at 750-820 ℃ for 100 s,the steel plates could obtain good universal properties,that the tensile strength and elongation could reach above 615 MPa and 21%,respectively.The tensile strength and yield strength increased with the increase of annealing temperature.The best elongation could be obtained when annealing at 820 ℃ and the better was at 800 ℃,while the elongation was relative poor when the annealing temperatures were 750 ℃ and 780 ℃.When the coiling temperature was 650 ℃,the strength of the steel plate after cold rolling and hot dip galvanizing annealing was higher than that of coiling at 690 ℃.