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.:
Date of Patent:
Nov. 29, 2011
Filed:
Sep. 24, 2008
Applicants:
Sumio Iida, Takanazuka, JP;
Yasuyoshi Hidaka, Kobe, JP;
Mitsuru Yoshizawa, Anagasaki, JP;
Koji Nakaike, Wakayama, JP;
Inventors:
Sumio Iida, Takanazuka, JP;
Yasuyoshi Hidaka, Kobe, JP;
Mitsuru Yoshizawa, Anagasaki, JP;
Koji Nakaike, Wakayama, JP;
Assignee:
Sumitomo Metal Industries, Ltd., Osaka-shi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B21B 17/10 (2006.01);
U.S. Cl.
CPC ...
Abstract
A method for surface treating a mandrel bar used for hot rolling of high-alloy seamless steel pipe is provided. The method includes heat treating the mandrel bar to develop a scale, and after heat treatment, rolling ordinary steel comprising 8% or less of chromium for at least 50 passes. This achieves a mandrel bar for rolling high-alloy steel possessing both durability and superior resistance to seizure.