| 摘要 |
PURPOSE:To detect a surface flaw of a square billet over the entire periphery by bringing probes into contact with both sides of the lowermost terminal corner of the diamond-shaped section of the square billet and performing flaw detection, and inverting the square billet by 180 deg. and performing the 2nd flaw detection. CONSTITUTION:The square billet BT is sent from a material feeding floor 23 to a conveyance table 24 and a flaw detecting mechanism UT-1 performs flaw detection. Surface probes 11 and 12 are brought into contact with both sides of the lowermost terminal corner of the diamond-shaped section of this square billet BT and surface waves are emitted clockwise and counterclockwise from the probes 11 and 12 as shown by chain lines to perform flaw detection. Then, the square billet BT is sent to an inverting machine 26 and inverted upside down by 180 deg.. Then the billet is sent to a flaw detection mecanism UT-2 and the 2nd flaw detection is carried out by the probes 11 and 12 from the opposite position of said flaw detection position. Thus, the flaw detection is performed by inverting the square bit, so even surfaces that the probes contact are detected and a surface flaw are detected completely over the entire peripheral surfaces of the square billet. |
