Abstract: Many irregular slag inclusion-like defects were found on the inspection surface of different stainless steels after grinding, coarse grinding, fine grinding and fine polishing for rating of the non-metallic inclusions. The morphology of defects was observed by means of optical microscope and scanning electron microscope, and the chemical composition of the defects was analyzed qualitatively and quantitatively by means of energy dispersive spectrometer. Meanwhile, the six elements of on-site quality management, namely human, machine, material, environment, method and measurement were used to conduct comparison and examination one by one in the whole process from steelmaking to specimen preparation, and to conduct the sandpaper comparison test with different materials. The results show that the slag inclusion-like defects mainly contain oxygen, aluminum and zirconium, and are caused by using zircon corundum sandpaper during grinding.

Key words: stainless steel, specimen preparation, slag inclusion-like defects, zircon corundum sandpaper