MANUFACTURING METHOD OF STEEL PIPE AND MANUFACTURING APPARATUS OF STEEL PIPE

• Main Authors: TSUTSUMI SATOSHI, URAHATA EIICHI, HARADA NAOMICHI, MATSUMIYA MASANORI
• Format: Patent
• Language: English; Japanese
• Published: 19.01.2022
• Subjects: AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PUNCHING METAL; TRANSPORTING

To provide a manufacturing method of a steel pipe which can prevent the quality deterioration due to twisting of a joint pipe after welding and a manufacturing apparatus of the steel pipe.SOLUTION: A manufacturing method of a steel pipe comprises: a heating step of heating an edge portion of band steel; a welding step of molding a tubular joint pipe by holding the band steel with at least one pair of pressure rolls, making the edge portions of the band steel face each other and welding the edge portions; a cooling step of cooling a seam portion of the joint pipe; a thermal image acquisition step of acquiring a thermal image by imaging the joint pipe; a twisting detection step of detecting twisting in the peripheral direction at the position of the seam portion based on the thermal image acquired in the thermal image acquisition step; and a correction step of correcting the twisting by displacing one of the pair of pressure rolls in the welding step in the thrust direction with respect to the other on the basis of the twisting detected in the detection step.SELECTED DRAWING: Figure 1 【課題】溶接後の接合管の捩じれによる品質の劣化を防止することができる鋼管の製造方法及び鋼管の製造装置を提供することを目的とする。【解決手段】鋼管の製造方法は、帯鋼のエッジ部を加熱する加熱工程と、少なくとも１対の圧延ロールを用いて帯鋼を挟んで帯鋼のエッジ部を互いに対向させ溶接することによって管形状の接合管を成形する溶接工程と、接合管のシーム部を冷却する冷却工程と、を有する鋼管の製造方法であって、接合管を撮像して熱画像を取得する熱画像取得工程と、熱画像取得工程において取得された熱画像に基づき、シーム部の位置の周方向の捩じれを検出する捩じれ検出工程と、検出工程により検出した捩じれに基づいて、溶接工程での１対の圧延ロールのうちの一方を他方に対してスラスト方向に変位させて捩じれを矯正する矯正工程とを有する。【選択図】図１