Mannesmann Precision Tubes France

Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Francis Bourguignon

Olivier Raccurt

Olivier Sicardy

Jean-Marie Gentzbittel

Pierre-Jean Marchais

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.

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Vitry-le-Francois, France

Francis Bourguignon