To provide a method and a device for inspecting a surface of a continuously-cast material suitable for inspecting the surface state of the continuously-cast material consisting of magnesium or a magnesium alloy, and a method for manufacturing a magnesium-based sheet.
The light is emitted from a light source 10 to a surface of a Mg-based cast material 100 consisting of magnesium or a magnesium alloy which is continuously cast by a continuous casting machine, and the diffused reflection light generated by the hit of the emitted light on a surface defect of the Mg-based cast material 100 is formed as a main detection light, and an image by the detection light is captured by an optical image pickup machine 11. Based on the image obtained by the optical image pickup machine 11, the surface state of the Mg-based cast material 100 is inspected by an image processing-inspection unit 12. An image with high bright-dark contrast is obtained by using an image by the diffused reflection light, not by the image by the specular reflection light of the emitted light from the light source 10. By using the image, any surface defect such as very small crack can be adequately detected.
NAGAI HIROSHI
NUMANO MASASADA
UCHIHARA TAKESHI
OISHI YUKIHIRO
KAWABE NOZOMI
