| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a seamless steel tube by Mannesmann piercing process by which thickness deviation and deterioration of biting ability are prevented and the generation of inside surface flaws is decreased in the manufacture of the seamless steel tube by Mannesmann piercing process. SOLUTION: When the seamless steel tube is manufactured by Mannesmann piercing process, in this manufacturing method of the seamless steel tube by Mannesmann piercing process, the lowering of ductility of a material to be pierced is prevented and the generation of the inside surface flaws caused by shear stress is prevented by setting the heating temperature of a billet and piercing speed so that the surface temperature of the inside surface of a hollow shell after billet heating and succeeding piercing rolling is 1,180-1,230°C. COPYRIGHT: (C)2006,JPO&NCIPI
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