电磁离心1Cr18Ni9Ti不锈钢的凝固组织与变形性能

SOLIDIFICATION MICROSTRUCTURE AND DEFORMATION OF STAINLESS STEEL 1Cr18Ni9Ti CAST BY ELECTROMAGNETIC CENTRIFUGAL CASTING

采用电磁离心铸造方法制备了1Cr18Ni9Ti不锈钢管坯.在电磁搅拌作用下,管坯铸态微观组织被细化,一次枝晶间距为40μm,与普通离心铸造相比减小70％;管坯的室温屈服强度为274MPa、延伸率为77％,分别比普通离心铸造管坯提高23％和28％.实验结果表明:电磁离心铸造可明显提高管坯的塑性加工性能,利用电磁离心管坯可直接进行冷轧1Cr18Ni9Ti不锈钢无缝薄壁管,实验得到的最大减薄率大于91.4％.

1Cr18Ni9Ti stainless steel tube blanks were produced by electromagnetic centrifugal casting. It was found that the as-cast microstructure of the blanks was refined due to electromagnetic stirring (EMS). Comparing with the tubes made by ordinary centrifugal casting, the prime dendrite arm space (40μm) is decreased by 70%; the yield strength is 274 MPa with a 23% improvement; and the elongation ratio (77%) is improved by 28%. The plastic deformation ability of the tubes was greatly improved by electromagnetic centrifugal casting. Thin-wall tubes of 1Cr18Ni9Ti stainless steel can be cold rolled from the as-cast blanks. The maximum reduction ratio of the tube wall is larger than 91.4% in this experiment.