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:
Mar. 25, 2008
Filed:
Jan. 29, 2003
Yoshimi Yamadera, Kobe, JP;
Eiki Nagashima, Chiba, JP;
Yoshimi Yamadera, Kobe, JP;
Eiki Nagashima, Chiba, JP;
Sumitomo Metal Industries, Ltd., Osaka, JP;
Toyo Engineering Corporation, Tokyo, JP;
Abstract
A duplex stainless steel for use in urea manufacturing plants, in mass %, consisting of C: 0.03% or less, Si: 0.5% or less, Mn: 2% or less, P: 0.04% or less, S: 0.003% or less, Cr: 26% or more, but less than 28%, Ni: 6-10%, Mo: 0.2-1.7%, W: more than 2%, but no more than 3%, N: more than 0.3%, but no more than 0.4%, with the balance being Fe and impurities, in which the content of Cu as an impurity is not more than 0.3%. The duplex stainless steel may also have Ca, Ce, and B content, and it is desirable that levels of Al and O (oxygen) as an impurities be no more than 0.05% and 0.01% respectively. Further, it is preferable that an increase in the Vickers hardness of the steel should not be more than 80, before and after the solution treated steel is subjected to the heat treatment of 800° C. for 30 minutes and subsequent water cooling. This duplex stainless steel possesses a high corrosion resistance.