Effect of Annealing Temperature and Temper Rolling on Mechanical Property and Microstructure of Cold Rolled Hot DIP Galvanized Dual Phase Steel

High strength cold rolled hot galvanized dual phase steels were pilot-produced in laboratory.The effect of different annealing temperatures and temper rolling parameters on the mechanical properties of dual phase steels had been studied.The results show that when the annealing temperature is higher than 800 ℃ the microstructure of low Si C-Mn-Cr system dual phase steel is composed of ferrite and martensite,and the general mechanical properties is preferable.Temper rolling can remarkably improve the yield strength and YS/TS ratio of dual phase steel and decrease total elongation slightly.When the temper rolling elongation is below 1%,the dual phase steel with excellent mechanical properties can be obtained for industry production.