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:
Apr. 23, 2024
Filed:
Mar. 15, 2019
Mannesmann Precision Tubes France, Saint-Florentin, FR;
Olivier Raccurt, Grenoble, FR;
Jean-Marie Gentzbittel, Grenoble, FR;
Olivier Sicardy, Grenoble, FR;
Francis Bourguignon, Vitry-le-Francois, FR;
Pierre-Jean Marchais, Vitry-le-Francois, FR;
MANNESMANN PRECISION TUBES FRANCE, Saint-Florentin, FR;
Abstract
A method for forming a layer of single-phase oxide (Fe, Cr)Owith a rhombohedral structure on a steel or super alloy substrate, may include, successively: (a) supplying a steel or super alloy substrate covered with a surface layer, the steel including at least 2 wt.-% chromium; (b) removing the surface layer in an atmosphere containing at least 0.2 atm O, creating a level of micro-deformation in the crystal lattice of the steel or super alloy that is greater than 1.0.10, and a heating at a heating rate higher than 400° C./s, such as to form a layer of rhombohedral oxide () (Fe, Cr)O; and (c) carrying out a thermal treatment, in the presence of air, at a water partial pressure of less than 10.000 ppm, and at a temperature varying in a range of from 400 to 1000° C., such as to grow the layer of rhombohedral oxide formed in the removing (b) to a thickness in a range of from 70 to 150 nm.