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. 03, 1979
Filed:
Jul. 19, 1978
Ludwig von Bogdandy, Oberhausen-Sterkrade, DE;
Hans Kosmider, Bremen, DE;
Klockner-Werke AG, Duisburg, DE;
Abstract
A compound steel material of high corrosion resistance is manufactured by alloying a carbon steel carrier material having a carbon content of at most 0.20C and of at least 0.04C with a carbide and nitride forming substance, compounding the alloyed carrier material with a ferritic chromium steel material of normal carbon content, followed by hot-rolling the compound steel material to a hot rolled strip or sheet which is then annealed at a temperature and for a time period sufficient for the carbon content of the ferritic chromium steel coating layer to be reduced to between 0.001 and 0.003% so as to increase the corrosion resistance of the chromium steel material to that of a superferritic material. After annealing, the sheet may be etched and surface-finished or cold-rolled, recrystallization annealed and thereafter surface-finished, such as temper-rolled. The ferritic chromium steel material has at most 0.1% of carbon prior to annealing. The carbide and nitride forming substance may be titanium whose content in the alloyed carrier material is preferably between 0.50% and 2.00%. The thickness of the ferritic chromium steel coating layer is between 50 and 500 .mu.m, the annealing temperature between 650.degree. and 900.degree. C., and the annealing time period between 8 and 72 hours.