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:
Jul. 13, 1976
Filed:
Jan. 15, 1975
Applicant:
Inventors:
Assignees:
Hitachi, Ltd., BOTH OF, JA;
Babcock-Hitachi Kabushiki Kaisha, BOTH OF, JA;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C23F / ;
U.S. Cl.
CPC ...
148-635 ; 148 315 ; 122D / ;
Abstract
A boiler tube and a method for manufacturing the same are disclosed in which an inner surface of the boiler tube used in the center of a high-temperature, high-pressure boiler is formed with a spinel layer consisting of an oxide of iron, chromium and nickel, which is exposed. The specific method of the manufacture is that after the boiler tube is brought into contact with high temperature steam, a magnetic iron (Fe.sub.3 O.sub.4) layer produced on the inner surface is removed.