304不锈钢冷轧板表面短线状剥落缺陷分析

针对304不锈钢冷轧板表面出现的短线状剥落缺陷，利用光学显微镜和扫描电子显微镜观察其形貌，利用能谱仪对局部成分进行了点扫描和面扫描检测。结果表明，304冷轧板表面短线状剥落缺陷微观形貌呈“凹槽”状，凹槽边部与正常表面结合部位呈分层台阶式结构，凹槽边缘存在铁和铬的氧化物。结合试验结果和相关研究分析推断，短线状剥落缺陷主要是由于铸坯三角区中铬偏析造成局部铁素体含量过高，热轧变形过程中产生局部微裂纹发生氧化，氧化膜在冷轧过程中被压延变形，经酸洗后部分覆盖在氧化膜上的基体剥落而形成。

Morphology analysis of short-line peeling defect on surface of 304 stainless steel cold-rolled sheet

The morphology of the short-line peeling defects on the surface of 304 stainless steel cold rolled sheet was observed using optical microscope and scanning electron microscope, the point analysis and surface distribution of local component were also detected using energy diffraction spectrometer. The results show that the microscopic morphology of short-line peeling defect on surface of 304 stainless steel cold rolled pickled sheet looks like a type of "groove", the bonding site of groove and normal surface appears layered step structure, and there is iron and chromium oxide film at the edge of the groove. According to experimental results and associated analysis, the short-line peeling defects are mainly due to the local high ferrite content caused by the segregation of Cr in triangle region of the slab. Then microcracks and local oxidation occur during hot rolling process. The oxide film deforms during cold rolling, and then the substrate covered on the oxide film peels off after pickling.