Title:
METHOD OF PRODUCING MARTENSITIC HIGH Cr STEEL SEAMLESS STEEL TUBE
Document Type and Number:
Japanese Patent JP2016196040
Kind Code:
A
Abstract:
PROBLEM TO BE SOLVED: To provide a manufacturing method for a martensitic high Cr steel seamless steel pipe excellent in inner face quality by efficiently suppressing wrinkle flaws generated on the inner surface of a steel pipe hot-finished by a diameter reduction rolling process with a stretch reducer and/or a sizer.SOLUTION: A method of producing a martensitic high Cr steel seamless steel tube is provided which sequentially comprises a step of heating a base material (round billet) having the composition of martensitic high Cr steel, a piercing rolling step, an elongation rolling step, a reheating step, and a diameter reduction rolling step. In the method of producing a martensitic high Cr steel seamless steel tube, a hollow element tube after the elongation rolling step is cooled down to a temperature of the Mf point or lower of the martensitic high Cr steel, then heated up to a temperature of Acpoint or higher in the reheating step, and successively subjected to diameter reduction rolled using a stretch reducer or a sizer.SELECTED DRAWING: Figure 1
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| JPS5992115 | COLD DRAWING METHOD OF METALLIC PIPE |
| WO/2011/083367 | TUBE ROLLING PLANT |
Inventors:
MATSUMOTO MASASHI
KATSUMURA TATSURO
TACHI RYOSUKE
IWAI YUJIRO
KATSUMURA TATSURO
TACHI RYOSUKE
IWAI YUJIRO
Application Number:
JP2015245195A
Publication Date:
November 24, 2016
Filing Date:
December 16, 2015
Export Citation:
Assignee:
JFE STEEL CORP
International Classes:
B21B23/00; B21B17/04; B21B17/14; C21D8/10; C22C38/00; C22C38/58
Domestic Patent References:
| JPH01123029A | 1989-05-16 | |||
| JPH01123029A | 1989-05-16 |
Attorney, Agent or Firm:
Kenichiro Ochiai