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:
Feb. 15, 1983
Filed:
Jan. 06, 1981
Nippon Steel Corporation, Tokyo, JP;
Abstract
In a process for the production of cold rolled ferritic stainless steel sheets or strips, a hot rolled strips has been annealed by a long time batchwise annealing and cold rolling and recrystallization annealing have been repeated usually twice. In the present invention, a hot rolled steel strip of an Al-containing ferritic stainless steel is heated by continuous annealing to a temperature of from 850.degree. to 1100.degree. C., AlN (aluminum nitride) is precipitated in the dispersed state and then cooling the strip to a temperature of 700.degree. to 900.degree. C., performing subsequent cooling to a level not higher than 200.degree. C. at such a cooling rate that a chromium depletion layer, which causes a gold dust defect, is not formed around the chromium carbonitride. Single cold rolling and recrystallization annealing are carried out in combination until the thickness is reduced to the gauge thickness.