| 摘要 |
PURPOSE:To confirm the possibility of generation of earing by detecting the state of distribution of temperature change parts of a pipe in the shape of a vertical stripe in the mandrel mill rolling of a pipe and diacriminating the presence or absence of fins causing earing in the following stage from the state of its distribution. CONSTITUTION:When a mandrel 2 is inserted into a hollow piece 8 and the hollow piece is rolled by the mandrel mill 3 to obtain a pipe 1, the distribution state of the temperature change part observed as distribution state of the vertical striped pattern generated on the pipe 1 is observed is measured by a distribution state detecting device 4 provided on the outlet side of the mandrel mill 3, the result is thrown into an arithmetic unit 16, compared with a preset criterion and whether the fins are generated or not is checked by the arithmetic unit 16 to remove parts of earing from the line. In this way, frequent occurrence of defective material by the earing can be prevented. |
