STAINLESS STEEL PIPE AND METHOD FOR MANUFACTURING SAME

WIPO Patent Application WO/2021/171836

A1

The purpose of the present invention is to provide: a stainless steel pipe that has exceptional corrosion resistance, high tensile yield strength in the axial direction of the pipe, a low difference between tensile yield strength and compressive yield strength in the axial direction of the pipe, and excellent fatigue characteristics of a threaded section; and a method for manufacturing the stainless steel pipe.　The present invention is a stainless steel pipe that has a prescribed constituent composition, containing N, Ti, Al, V, and Nb so as to fulfill a prescribed formula; the tensile yield strength in the axial direction of the pipe is at least 757 MPa; the ratio of the compressive yield strength in the pipe axial direction to the tensile yield strength in the pipe axial direction is 0.85–1.15; the structure is such that, by volume fraction, 20–80% is a ferrite phase, with the remainder being an austenite phase; a male-threaded or female-threaded fastening section is provided on at least one end section of the pipe; and the radius of curvature of an angle section R formed by a thread valley floor surface and a pressure-side flank surface in an cross-section of the fastening section in the pipe axial direction is at least 0.2 mm.

SASAKI SHUNSUKE (JP)
YUGA MASAO (JP)
KATSUMURA TATSURO (JP)
KIJIMA HIDEO (JP)

PCT/JP2021/001884

September 02, 2021

January 20, 2021

Click for automatic bibliography generation  

JFE STEEL CORP (JP)

B21D3/00; C21D8/10; C21D9/08; C21D9/50; C22C38/00; C22C38/58; C22C38/60

WO2014034522A1	2014-03-06
WO2015182128A1	2015-12-03
WO2020110597A1	2020-06-04

JP2003525354A	2003-08-26
CN101353769A	2009-01-28
JP5500324B1	2014-05-21
JPH034093B2	1991-01-22

See also references of EP 4086016A4

KUMASAKA Akira et al. (JP)

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