| 摘要 |
PURPOSE:To always form a good coating film on the surface of a mandrel bar by providing a by-pass conveying means for feeding said bar newly and conveying the bar without passing the same through a cooler if the bar does not attain a prescribed temp. CONSTITUTION:When the temp. of a blank pipe right after the start of rolling operations is not sufficiently high, a mandrel bar is conveyed from a mandrel bar returning conveyor directly to a mandrel bar inserter table with a by-pass conveying means without passing the same through a cooler. Then the mandrel bar which does not yet attain a high temp. is fed to the mandrel bar inserter table without being cooled by the cooler. Thereafter, a lubricant is coated on the surface of the bar, whereby a coating film is formed thereon. |
