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:
Nov. 15, 1994
Filed:
Sep. 03, 1993
Robert A Rapp, Columbus, OH (US);
Mark A Harper, Columbus, OH (US);
Ohio State University Research Foundation, Columbus, OH (US);
Abstract
Diffusion coatings incorporating approximately 18 to 35 wt % Cr and 1 to 3% Si in 2.25Cr-1.0Mo steel and 1018 steel have been produced using a pack cementation method. The codeposition of these concentrations of Cr and Si into the 2.25Cr-1.0Mo and 1018 steel requires the use of a 'mixed activator' (fused salt solution of NaF and NaCl). Cyclic oxidation tests in air at 700.degree. C. of a coated 2.25Cr-1.0Mo steel coupon with a surface concentration of 34Cr-3Si have shown excellent cyclic oxidation resistance. Furthermore, a 1018 coupon coated to a surface concentration of Fe-30 wt % Cr-3Si shows negligible aqueous corrosion in an aerated 3.5% NaCl solution at room temperature. These coatings have provided similar protection in more complex oxidizing and reducing atmospheres.