Abstract: A method of manufacturing a steel part including a support part and a portion formed by a filler metal in the form of molten metal on the support part to form a heat affected zone and a molten zone between the HAZ and the portion formed by adding molten metal. The support part is made of a 70-100% martensitic microstructure steel, the composition of which consists of defined percentages of: C; N; Mn; Si; Al; S+P; Cr; Ni; Mo+W; Cu; Ti+Nb+Zr+V+Ta; Co; Sn+Pb; and B; the remainder being iron. The composition of the filler metal before use consists of defined percentages of: C; N; Mn; Si; Cr; Ni; Mo+W; Cu; Co; B; S+P; Ti+Nb+Zr+V+Ta; Sn+Pb; the remainder being iron.

Abstract: A process for surface treatment of metal substrates, including the steps of: providing a metal substrate including hydroxyl groups at its surface; bringing the metal substrate into contact with a solution of at least one organophosphorus compound to enable the reaction of the hydroxyl groups at the surface of the metal substrate with the organophosphorus compound to form a monomolecular layer over the surface and a second layer of physisorbed organophosphorus molecules at least preponderantly crystallized, the obtained treated substrate being coated with the organophosphorus compound in the form of a first monomolecular layer coating at least 15% of the surface of the substrate and in the form of a physisorbed second layer at least preponderantly crystallized. A treated metal substrate which may be obtained by the process thereof, corresponding solution and its use for treating metallic substrates to improve their tribological properties during their shaping, in particular their stamping.

Abstract: A process for surface treatment of metal substrates, including the steps of: providing a metal substrate including hydroxyl groups at its surface; bringing the metal substrate into contact with a solution of at least one organophosphorus compound to enable the reaction of the hydroxyl groups at the surface of the metal substrate with the organophosphorus compound to form a monomolecular layer over the surface and a second layer of physisorbed organophosphorus molecules at least preponderantly crystallized, the obtained treated substrate being coated with the organophosphorus compound in the form of a first monomolecular layer coating at least 15% of the surface of the substrate and in the form of a physisorbed second layer at least preponderantly crystallized. A treated metal substrate which may be obtained by the process thereof, corresponding solution and its use for treating metallic substrates to improve their tribological properties during their shaping, in particular their stamping.