摘要 |
A method for detecting a surface defect or flaw of metallic material, comprising the steps of subjecting the surface layer of metallic material to high-frequency induction heated in a linear manner, transferring the heating portion of the surface layer of the metallic material, measuring the surface temperature of the metallic material after its being subjected to heating, and determining the depth of the surface defect or flaw on the basis of the level of the value of temperature rise. |