Analysis on Surface Upwarp Defects of Heat-resistant Stainless Steel Plate 310S

Surface upwarp defects of heat-resistant stainless steel plate 310 S were investigated by means of optical microscope(OM) and scan electron microscope(SEM).The results show that the main causes of surface upwarp defects are the protective slag entrapped in the process of casting and iron oxide pressed during hot rolling.The surface upwarp defects appears different morphology and distribution profile through the surface to the matrix.The oxide inclusions of chromium are found in the internal of defects,but oxide inclusions of iron and silicon are present on surface of defects.