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. 02, 1988
Filed:
Nov. 29, 1985
Yasuhiro Maehara, Kobe, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Abstract
A duplex .alpha. (ferrite) and .gamma. (austenite) phase stainless steel exhibiting superplasticity at high strain rate is disclosed. The steel comprises Fe, Cr, and Ni as primary elements, and N in an amount of 0.05-0.25%, preferably 0.1-0.2% by weight. The amount of Cr+Mo+1.5xSi is preferred to be substantially three times as much as that of Ni+0.5.times.Mn+30.times.C+25.times.N. The disclosed steel shows good superplasticity in the temperature range of from 700.degree. C. to the point 100.degree. C. lower than the temperature at which the steel transforms into a single ferrite phase and at a strain rate of at least 1.times.10.sup.-6 s.sup.-1 and less than 1.times.10.sup.0 s.sup.-1, and can be elongated by more than 1000% at 900.degree. C. and at a strain rate of 1.5.times.10.sup.-2 s.sup.-1.