Abstract: The present invention relates to a method for treating a part (P) made of iron alloy for improving the anti-corrosion and mechanical strength properties thereof, the method comprising: a salt bath nitriding or salt bath nitrocarburising step, to form a combination layer (1) on the part (P), and subsequently a step of phosphating the part (P), to form a phosphating layer (2) on the surface of the part, characterised in that the bath of molten salts contains chlorides, and the phosphating step is carried out in a phosphating bath which contains zinc ions and/or manganese ions, and iron ions.

Abstract: A method for treating a part made of ferrous metal includes a nitriding operation forming on the part a combination layer having a thickness of between 5 and 30 ?m, and a diffusion region, arranged beneath and in contact with the combination layer, having a thickness of between 100 ?m and 500 ?m. The method also includes an operation of quenching the part by high-frequency induction, over an induction depth that is greater than or equal to 0.5 mm, thereby hardening the part. The resulting part has a surface hardness greater than or equal to 50 HRC, a hardness of the combination layer greater than or equal to 400 HV0.05, and a hardness of the part greater than or equal to 500 HV0.05 at a depth of 500 ?m. The high-frequency induction quenching operation is performed without the application of a protective film on the part prior to the induction quenching operation.

Abstract: A method for treating a part made of ferrous metal includes a nitriding operation forming on the part a combination layer having a thickness of between 5 and 30 ?m, and a diffusion region, arranged beneath and in contact with the combination layer, having a thickness of between 100 ?m and 500 ?m. The method also includes an operation of quenching the part by high-frequency induction, over an induction depth that is greater than or equal to 0.5 mm, thereby hardening the part. The resulting part has a surface hardness greater than or equal to 50 HRC, a hardness of the combination layer greater than or equal to 400 HV0.05, and a hardness of the part greater than or equal to 500 HV0.05 at a depth of 500 ?m. The high-frequency induction quenching operation is performed without the application of a protective film on the part prior to the induction quenching operation.