对BT303CuS易切削不锈钢热轧过程中产生的轧件头部开裂原因进行了分析,发现轧件劈头与钢中硫化物的形态有关,利用热模拟实验研究了加热温度对轧件硫化物形态变化影响,在此基础上确定出最佳加热温度范围是1200~1280℃.同时采取了控制轧件头部冷却水、使用新型导卫及增设工序飞剪等一系列工艺措施,显著减少了轧制缺陷,中间废品率由5.67%下降到1.38%,使宝钢股份特钢事业部长型材生产线形成批量生产该钢的能力.
The causes of head splits of a workpiece in hot rolling process of free-cutting stainless steel were analyzed.It was found that there is a relationship between the head splits and morphology of sulphides in the steel.A thermomechanical simulation test was therefore carried out to investigate the effect of reheating temperature on the sulphide morphology,and the optimum range of reheating temperature was determined as 1 200~1 280 ℃.Then,some measures were taken to get rid of the heat splits,such as controlling the cooling water at the workpiece head,using the new-type guide/guard system and adding a flying shear to cut the workpiece head.Thus,the intermediate rejection rate was decreased from 5.67% to 1.38%.Now the different rolled products of BT303CuS steel has come into batch production in Baoshan Iron & Steel Co.,Ltd..