METHOD AND APPARATUS FOR INSPECTING SURFACE DEFECT OF CONTINUOUSLY CAST STEEL PIECE

PURPOSE:To improve the quality of the surface of a product by performing acid cleaning of a continuously cast steel piece after cooling, and detecting the defect in the surface after the acid cleaning of the continuously cast steel piece. CONSTITUTION:A continuously cast steel piece undergoes acid cleaning in an acid cleaning tank after cooling. Then the surface of the steel piece becomes white tinged with lead color. A camera 14 having a magnifying lens whose magnification is about 4, which can scan along the surface of a material under inspection 13 by moving the camera in the directions of A-B and C-D, is provided on the material under inspection, 3 whose acid cleaning has been finished. The camera 14 is moved with a controller 16. The picked-up image from the camera 14 is displayed on a monitor 15, and the image displayed onthe monitor 15 is observed. Thus, the surface defect of the material under inspection 13 after the acid cleaning can be more clearly recognized, and the surface quality of the product can be improved.