翼缘板钢非对称冷轧及再结晶退火实验研究

Research of Asymmetrical Cold Rolling and Recrystallization Annealing Experiment of Flange Plate Steel

对翼缘板钢采用非对称冷轧,在压下率78%时,对轧件进行微观显微组织观察,结果表明:随着异速比增大,晶粒长度和宽度比值也增大;提出了在异步轧制条件下,晶粒长宽比值可以反映轧件所受附加剪切变形的大小。对冷轧后的轧件进行拉伸实验与不同温度的退火实验,并进行透射电镜观察,结果表明:随着异速比增加,规定非比例延伸强度增加,退火后晶粒平均直径变小;同时,观察到了较高位错密度的位错和较小尺寸的亚晶;由此验证了异步轧制可比同步轧制产生更多的附加剪切变形以及更多的位错和亚晶,可以提高翼缘板钢的强度,增加应变储能,降低再结晶退火温度。

Asymmetrical cold rolling technology was adopted for flange plate steel.Microstructure of rolled pieces was observed under the accumulated reduction of 78%.The results show that as the ratio of working rollers＇ speed is greater,the ratio of length to width of gain is higher.The idea is put forward that the ratio of length to width of gain can reflect the additional shear deformation size of rolled pieces under the condition of asymmetrical rolling.The tensile tests and annealing tests at different annealing temperatures were made for cold rolled pieces and the microstructure was observed by the transmission electron microscopy.The results show that as the ratio of working rollers＇ speed is greater,proof strength increases,average grain diameter decreases after cold rolled pieces annealed.With increase of the ratio of working rollers＇ speed,high density dislocations and the small size subgrains are observed.It indicates that asymmetrical rolling can present more additional shear strain than that of symmetrical rolling,more dislocations and subgrains can be generated in the course of asymmetrical rolling,and the strength of the flange plate steel is enhanced and the straining accumulation energy increases under the condition of asymmetrical rolling.It proves that annealing temperature of recrystallization is reduced.