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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 11293072 B1

PDFFull Text
Date of Patent:
Apr. 05, 2022

Filed:

Sep. 21, 2016

Process for on-line quenching of seamless steel tube using residual heat and manufacturing method

Applicant:

Baoshan Iron & Steel Co., Ltd., Shanghai, CN;

Inventors:

Zhonghua Zhang, Shanghai, CN;

Yaoheng Liu, Shanghai, CN;

Ke Xu, Shanghai, CN;

Assignee:

BAOSHAN IRON & STEEL CO., LTD., Shanghai, CN;

Attorney:

Neal, Gerber & Eisenberg LLP

Primary Examiner:

Brian D Walck

Int. Cl.
CPC ...
C21D 9/08 (2006.01); C22C 38/04 (2006.01); C22C 38/08 (2006.01); C21D 11/00 (2006.01); C22C 38/06 (2006.01); B21B 19/04 (2006.01); C21D 1/667 (2006.01); C21D 1/18 (2006.01); C21D 6/00 (2006.01); C22C 38/00 (2006.01); C22C 38/02 (2006.01); C22C 38/12 (2006.01); C22C 38/40 (2006.01); C21D 8/10 (2006.01);
U.S. Cl.
CPC ...
C21D 9/085 (2013.01); B21B 19/04 (2013.01); C21D 1/18 (2013.01); C21D 1/667 (2013.01); C21D 6/005 (2013.01); C21D 6/008 (2013.01); C21D 9/08 (2013.01); C21D 11/005 (2013.01); C22C 38/002 (2013.01); C22C 38/02 (2013.01); C22C 38/04 (2013.01); C22C 38/06 (2013.01); C22C 38/08 (2013.01); C22C 38/12 (2013.01); C22C 38/40 (2013.01); C21D 8/10 (2013.01); C21D 8/105 (2013.01); C21D 2211/002 (2013.01); C21D 2211/003 (2013.01); C21D 2211/005 (2013.01); C21D 2211/008 (2013.01); C21D 2211/009 (2013.01);
Abstract

An process for the on-line quenching of seamless steel tube using residual heat, a method for manufacturing a seamless steel tube, and a seamless steel tube. The process for the on-line quenching of a seamless steel tube comprises the following steps: when the temperature of a tube is higher than Ar3, evenly spraying water along a circumferential direction of the tube so as to continuously cool the tube to be not higher than T° C., the cooling rate being controlled to be E1° C./s to E2° C./s to obtain a microstructure with martensite as the main composition, wherein T=Ms−95° C., Ms represents the martensitic phase transition temperature, E1=20×(0.5−C)+15×(3.2−Mn)−8×Cr−28×Mo−4×Ni−2800×B, and E2=96×(0.45−C)+12×(4.6−Mn), and the C, Mn, Cr, Ni, B and Mo in the equations each represents the mass percentages of corresponding elements in the seamless steel tube.

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