| 摘要 |
PURPOSE:To descale surely during sizing by specifying a stage for starting descaling at the time of sizing a seamless steel pipe by a sizing mill consisting of plural stands in the seamless steel-pipe manufacture of Mannesmann plug-system. CONSTITUTION:In a method for sizing a seamless steel pipe by a sizing mill consisting of plural stands; after rolling the pipe by the 1st stand of the mill, highly pressurized water is sprayed on the outer surface of a pipe stock at the front of at least the 2nd stand, to descale said outer surface. For instance, the 1st and 2nd highly-pressurized water spraying headers 5, 6 are arranged on the backsides of the stands 1, 2 of the stands 1-4 of sizing mill. The water is sprayed on the surface of pipe stock from the header 5 by a load cell when the pipe stock is bitten by the stand 1 to descale the pipe surface, and the header 6 performs the descaling in the same manner when the pipe stock is bitten by the stand 2. By this method, the scales are easily stripped under light rolling reduction, and the descaling is surely performed by water of comparatively low pressure. |
