Method for surface treatment of a steel component by nitriding or nitrocarburising, oxidising and then impregnating

A method of surface treatment of a steel part to give it a high resistance to wear and to corrosion comprising

• a step of nitriding or of nitrocarburizing adapted to form a combination layer of at least 8 micrometers thickness formed of iron nitrides of ε and/or γ′ phases,
• an oxidizing step adapted to generate a layer of oxides of thickness comprised between 0.1 and 3 micrometers and
• a step of impregnating by steeping in an impregnation bath for at least 5 minutes, said bath being formed of at least 70% by weight, to the nearest 1%, of a solvent formed of a mixture of hydrocarbons formed of a set of alkanes from C9 to C17, of 10% to 30% by weight, to the nearest 1%, of at least one paraffin oil composed of a set of alkanes from C16 to C32 and of at least one additive of synthetic phenolic additive type at a concentration comprised between 0.01% and 3% by weight, to the nearest 0.1%, at ambient temperature.