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The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.

The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.

Patent No.:

US 10837073 B1

PDFFull Text
Date of Patent:
Nov. 17, 2020

Filed:

Feb. 20, 2015

High-strength heavy-walled stainless steel seamless tube or pipe and method of manufacturing the same

Applicant:

Jfe Steel Corporation, Tokyo, JP;

Inventors:

Shunsuke Sasaki, Handa, JP;

Tatsuro Katsumura, Handa, JP;

Yasushi Kato, Handa, JP;

Assignee:

JFE Steel Corporation, Tokyo, JP;

Attorney:

DLA Piper LLP (US)

Primary Examiner:

John A Hevey

Int. Cl.
CPC ...
C21D 9/08 (2006.01); C21D 6/00 (2006.01); C21D 8/10 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/04 (2006.01); C22C 38/06 (2006.01); C22C 38/42 (2006.01); C22C 38/44 (2006.01); C22C 38/46 (2006.01); C22C 38/48 (2006.01); C22C 38/50 (2006.01); C22C 38/54 (2006.01); C22C 38/58 (2006.01); C21D 7/12 (2006.01); B21B 3/02 (2006.01); B32B 19/04 (2006.01); C21D 1/25 (2006.01); B21B 19/04 (2006.01); C21D 1/18 (2006.01);
U.S. Cl.
CPC ...
C21D 9/08 (2013.01); B21B 3/02 (2013.01); B21B 19/04 (2013.01); C21D 1/25 (2013.01); C21D 6/004 (2013.01); C21D 6/005 (2013.01); C21D 6/007 (2013.01); C21D 7/12 (2013.01); C21D 8/10 (2013.01); C21D 8/105 (2013.01); C22C 38/00 (2013.01); C22C 38/001 (2013.01); C22C 38/002 (2013.01); C22C 38/005 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/42 (2013.01); C22C 38/44 (2013.01); C22C 38/46 (2013.01); C22C 38/48 (2013.01); C22C 38/50 (2013.01); C22C 38/54 (2013.01); C22C 38/58 (2013.01); C21D 1/18 (2013.01); C21D 2211/001 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01);
Abstract

A high-strength heavy-walled stainless steel seamless tube or pipe exhibiting excellent low-temperature toughness is characterized by having a chemical composition containing Cr: 15.5% to 18.0% and a steel microstructure containing a ferritic phase and a martensitic phase, wherein the maximum value of the areas of the ferrite grains in the steel microstructures in a circumferential direction cross section and an L direction (rolling direction) cross section of the steel tube or pipe is 3,000 μmor less and the content of ferrite grains having areas of 800 μmor less is 50% or more on an area fraction basis, where, when adjacent ferrite grains are present in the steel microstructure and the crystal misorientation between one ferrite grain and the other ferrite grain is 15° or more, the adjacent grains are assumed to be grains different from each other.

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