To provide a rolling control method for a mandrel mill by which a tube having high dimensional accuracy is manufactured and rolling trouble can be suppressed.
In the rolling control method for the mandrel mill, an ultrasonic thickness meter 1 is installed between prescribed stands and the wall thickness at the groove bottom of a tube P is measured at a stand just before the installation position of the thickness meter 1. The outside diameter of a mandrel bar B is calculated on the basis of the preset value of roll gap at the just-before stand and the wall thickness at the groove bottom of the tube. On the basis of information on the position of a bar retainer BR, the portion of the mandrel bar in the longitudinal direction where the outside diameter is calculated is specified. By repeating above steps, the longitudinal distribution of the outside diameter of the mandrel bar is calculated. On the basis of the information on the position of the bar retainer, the portion of the mandrel bar in the longitudinal direction used when rolling the tube in a stand of the poststage is specified and, on the basis of the outside diameter of the mandrel bar in the specified portion in the longitudinal direction, the roll gap in the stand of the poststage is set.
JPS56134011 | ROLLING METHOD FOR MANNESMANN PLUG MILL |
JPS6193904A | 1986-05-12 | |||
JPS61135409A | 1986-06-23 |
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