| 摘要 |
<p>PURPOSE:To prevent a seamless steel pipe from producing wall-thickness deviation by detecting the displacement quantity of the axial center of a rolling plug with respcet to the center line in the logitudinal direction of a pass line and controlling the position of a guide shoe so as to make the displacement to be zero in rolling a round billet pierced by a piercer into a seamless steel pipe by a skew rolling mill. CONSTITUTION:A round-bar-shaped steel billet 3 pierced by a piercer is rolled into a seamless pipe by a skew rolling mill equipped with upper and lower skew rolls 1, 2, a rolling plug 7 attached to a plug bar 6, and guide shoes 4, 5 provided to both sides of bar 6. In this case, the displacement quantity S of plug bar 6 with respect to the pass line PL of said mill is detected by a sensor, and the positions of guide shoes 4,5 located at both sides of billet 3 are controlled to the left or rightward direction so as to converge the displacement S into zero. In this way, a seamless steel pipe free from wall-thickness deviation is stably manufactured by a skew rolling mill.</p> |
