ELECTROSEAMED STEEL PIPE, AND METHOD FOR MANUFACTURING SAME

WIPO Patent Application WO/2021/200402

A1

Provided are: an electroseamed steel pipe having high strength and excellent toughness and buckling resistance; and a method for manufacturing same.　The electroseamed steel pipe has a base metal part and an electroseamed welded part, wherein: the base metal part has a component composition containing predetermined amounts of C, Si, Mn, P, S, Al, N, Nb, V, and Ti, in mass%, respectively, with the balance being Fe and unavoidable impurities; and a steel structure in the thick-walled central portion of the base metal has at least 70% in total of ferrite and bainite in terms of volume fraction, with the balance comprising at least one or two selected from among pearlite, martensite, and austenite, has an average crystal grain size of 7.0 μm or less, has a dislocation density of 1.0×1014-6.0×1015m-2, and has a magnitude of residual stress in the pipe axial direction on the inner and outer surfaces of the pipe of 150 MPa or less.

MATSUMOTO AKIHIDE (JP)
MATSUMOTO ATSUSHI (JP)
IDE SHINSUKE (JP)
OKABE TAKATOSHI (JP)

PCT/JP2021/012024

October 07, 2021

March 23, 2021

Click for automatic bibliography generation  

JFE STEEL CORP (JP)

C22C38/00; B21C37/08; C21D8/02; C21D9/08; C21D9/50; C22C38/60

WO2013099192A1	2013-07-04
WO2020202333A1	2020-10-08
WO2021085036A1	2021-05-06
WO2017163987A1	2017-09-28

JP6575734B1	2019-09-18
JP6052374B2	2016-12-27

T. UNGARA. BORBELY, APPL.PHYS.LETT., vol. 69, 1996, pages 3173
M. KUMAGAIM. IMAFUKUS. OHYA, ISIJ INTERNATIONAL, vol. 54, no. 1, 2014, pages 206
See also references of EP 4095280A4

KUMASAKA Akira et al. (JP)

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