321不锈钢工艺控制及成品板缺陷形成机理研究

Process Control and Defect Formation Mechanism of 321 Stainless Steel

介绍了某钢厂炉卷轧机生产321不锈钢的化学成分设计、生产工艺控制和成品板的力学性能,并利用光学显微镜、扫描电镜对生产的321不锈钢夹杂物形貌及成品板表面缺陷进行了观察与分析。结果表明:炉卷轧机生产的321不锈钢力学性能优良,表面质量较好,其主要的表面缺陷为线鳞,是由于连铸坯中TiN夹杂物大量聚集造成的。控制影响夹杂物产生的Ti、Al、N、O等元素含量,设置合理的LF炉吹氩搅拌参数,控制浇注时的过热度等措施可有效改善321不锈钢成品板的表面质量。

The technical features of 321 stainless steel produced by steekle mill were introduced in this paper, including its alloying design, process control and mechanical properties. Morphology of the inclusions and the surface defects of the steel were analyzed by OM and SEM. The results showed that the 321 siainless steel exhibits excellent mechanical property and good surface quality. The main surface defect is linear scale, which is caused by the mass clustering of TiN grains in the continuously cast bloom. In order to effectively improve the surface quality of the steel, some measures can be taken, including controlling contents of elements such as Ti, Al, N, and O and degree of superheat during casting, and setting reasonable parameters of argon stirring in LF.