To provide a method for producing a seamless steel pipe made of a high Cr-high Ni-based alloy in which the generation of melted inside rash is prevented, and also, the service life of a plug can be improved.
When the stock to be rolled made of a high Cr-high Ni based alloy steel comprising, by mass, 20 to 30% Cr, 30 to 50% Ni and one or more selected from Mo and W by 1.5% in terms of Mo+0.5W is subjected to gradient piercing rolling, the stock to be rolled is heated under the conditions satisfying inequality; T1575-4.45Vf-104.7{-ln(th/ro)}, and is thereafter subjected to gradient piercing rolling under the conditions satisfying a roll gorge peripheral speed (m/sec) of 2.3 m/sec. In the inequality, T denotes a heating temperature (C); Vf denotes the roll peripheral speed (m/sec) in the roll gorge; ro denotes the radius (mm) of an inlet side stock billet; and th denotes the thickness (mm) of the pipe stock after the piercing.
YAMAKAWA TOMIO
SHIMODA KAZUMUNE
JPS6431505A | 1989-02-01 | |||
JPH11169914A | 1999-06-29 | |||
JP2000334505A | 2000-12-05 |
WO2004108310A1 | 2004-12-16 |
Terutada Hogami
Chihara
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