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:
May. 21, 1996
Filed:
Oct. 31, 1994
Masaru Sagiyama, Tokyo, JP;
Masaki Abe, Tokyo, JP;
Junichi Inagaki, Tokyo, JP;
Akira Hiraya, Tokyo, JP;
Masaya Morita, Tokyo, JP;
NKK Corporation, Tokyo, JP;
Abstract
It is an object to provide a process for manufacturing galvannealed steel sheets exhibiting excellent anti-powdering property when press formed, and uniform frictional properties in a coil. A steel strip is galvanized in a bath having a low aluminum content after entering it at a high temperature as defined in relation to the aluminum content of the both, so that the formation of a .zeta. phase may be promoted. Then, the strip is heated for alloying in a high-frequency induction heating furnace so as to have a temperature not exceeding 495.degree. C. when leaving the furnace to yield a plated steel strip having a coating containing a uniformly distributed .zeta. phase. After such heat treatment and cooling, the strip can be plated with an iron or iron-alloy top coating having an iron content of at least 50% and a coating weight of at least 1 g/m.sup.2 to achieve an improved press formability.