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. 23, 1996
Filed:
Oct. 04, 1995
Nippon Steel Corporation, Tokyo, JP;
Abstract
Welded steel pipe having wear resistance properties, corrosion resistance and low-temperature toughness is provided by preparing welded steel pipe formed of composite steel material comprised of an outer layer of high-carbon, low-alloy steel and an inner layer having a relatively low carbon content, heating the pipe to a temperature that is not less than 800.degree. C. and not more than 900.degree. C. and then quenching the pipe so as to harden just the high-carbon outer layer, and if necessary this can be followed by reheating at a temperature of not less than 200.degree. C. and not more than 600.degree. C. to thereby produce a pipe with an inner layer having high corrosion resistance and low temperature toughness and an outer layer having high hardness.