| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the quality and the yield of a tube by continuously operat ing the average thickness of the tube during manufacturing the tubes, and con trolling the thickness of the tube according to a principle that a mass flow on the inlet/outlet sides of a stretch reducer is constant when manufacturing butt-welded steel tubes. SOLUTION: After heating a skelp and making it a tube stock by a forge welding machine, when manufacturing a prescribed butt-welded steel tube by using the stretch reducer, the thickness of the tube must be always and continuously controlled by the reducer by using an average thickness on the outlet side of the reducer, which is operated from the following formula. where t1 : Plate thickness at the time of the skelp of the tube on the outlet side of the reducer v1 : Speed at the time of the skelp of the tube on the outlet side of the reducer v2 : Speed of the tube on the outlet side of the reducer w: Width of the skelp D: Outside diameter of the tube on the outlet side of the reducerα: Young's modulus of a volume, caused by a scale lossβ: Young's modulus by thermal expansion.</p> |
