采用光学显微镜、扫描电镜和X射线衍射仪等对200系奥氏体不锈钢在轧制过程中出现裂纹的原因进行了分析;在此基础上,运用Gleeble 1500D型热模拟试验机对该系钢进行了高温拉伸试验,获取热变形数据以改进生产工艺.结果表明:网状分布的铁素体是热轧开裂的主要原因,断口周围的夹杂物、σ相、碳化物、氧化物和金属间化合物是开裂的另一诱因;为避免开裂,应严格控制轧制温度范围,D11和J4钢的控制在(1 200±25)℃,D7钢为(1 100±25)℃,终轧温度保持在950℃以上.

The cracking causes of the 200 series austenitic stainless steels during hot rolling were analyzed by using optical microscopy,SEM and XRD.In order to get the thernal deformation data and improve the production technology,high temperature tensile test was performed by using Gleeble 1500D thermal simulator.The results show that the main cause of hot rolling cracking was the ferrite distributed in the form of net.The inclusions,σ phase,carbides,oxides and intermetallic compounds distributed around the fracture were the inducement of cracking.It was suggested that for avoiding the cracking,the rolling temperature range of D11 and J4 steels should be strictly controlled to be(1 200±25)℃ and(1 100±25)℃ respectively,and the finishing temperature should above 950℃.