Influence of Heating Rate on Recrystallization Texture of Cold Rolled Deep Drawing Steel Sheet

The recrystallization annealing tests with different heating rate（2 ℃/min,20 ℃/min,350 ℃/min） and holding time（10 min,60 min,300 min） of CSP-DC04 cold rolled deep drawing steel sheet（wt%:0.02 C、0.03 Si、0.2 Mn、0.02 P、0.008 S、0.04 Als、0.007 N） had been conducted by a laboratory tubular resistance furnace.Microstructure and recrystallization texture were studied by means of electron back-scatter diffraction technology（EBSD）,X-ray diffraction（XRD） and metallographic microscope.The results showed that holding time has significant effect on the recrystallization texture,but little effect on the grain morphology.Heating rate has strong effect on the grain morphology and recrystallization texture.The grains are fine and equiaxed after fast heating rate annealing（350 ℃/min）,the α-fiber microtexture and γ-fiber microtexture strengthened with the increasing of holding time.Its nucleation mechanism is directional nucleation-sub grain merge nucleation.However,the grains are pancake-shaped along the rolling direction when annealing at slow heating rate（2 ℃/min）,the α-fiber microtexture weakened with the increasing of holding time but the γ-fiber microtexture strengthened firstly and weakened later with the increasing of holding time,its nucleation was controlled by selective growth-boundary bulge out nucleation mechanism.