With the method according to the invention, mould parts for casting moulds for light metal casting can be treated such that the danger of crack formation in the region of the surface sections of the mould part coming into contact with the light metal melt during casting is reduced to a minimum. This is achieved in that by means of nitriding treatment on the mould part a nitride-hardened edge layer adjoining its free surface is generated which is harder than the inner core region of the mould part and comprises a diffusion layer adjoining the core region and a compound layer located on the diffusion layer and adjoining the free surface of the mould part and in that at least one section of the surface of the mould part is mechanically processed by machine hammer peening, in the case of which a hammer tool, which, at a certain impact frequency, carries out an impact movement along a movement axis which is aligned in relation to the free surface at a certain acute angle, is guided continuously over the free surface of the mould part following a track determined in a preceding design step such that the compound layer is removed by the impacting stress in the impact region of the hammer tool.

With the method according to the invention, mould parts for casting moulds for light metal casting can be treated such that the danger of crack formation in the region of the surface sections of the mould part coming into contact with the light metal melt during casting is reduced to a minimum. This is achieved in that by means of nitriding treatment on the mould part a nitride-hardened edge layer adjoining its free surface is generated which is harder than the inner core region of the mould part and comprises a diffusion layer adjoining the core region and a compound layer located on the diffusion layer and adjoining the free surface of the mould part and in that at least one section of the surface of the mould part is mechanically processed by machine hammer peening, in the case of which a hammer tool, which, at a certain impact frequency, carries out an impact movement along a movement axis which is aligned in relation to the free surface at a certain acute angle, is guided continuously over the free surface of the mould part following a track determined in a preceding design step such that the compound layer is removed by the impacting stress in the impact region of the hammer tool.

A method for manufacturing of steel articles comprises nitriding (210) a steel article at a nitrification temperature in the interval 350-650 C., giving a nitrided steel article. The nitrided steel article is quenched (220) in a reactive quenching oil from the nitrification temperature. The reactive quenching oil comprises at least one of S, P, B, Mo and W. Thereby, the quenching additionally comprises coating (222) of the nitrided steel article by a solid lubricant comprising at least one of S, P, B, Mo and W. An apparatus for manufacturing of steel articles, a quenching oil and a steel article produced by the method are also disclosed.

A method for manufacturing of steel articles comprises nitriding (210) a steel article at a nitrification temperature in the interval 350-650 C., giving a nitrided steel article. The nitrided steel article is quenched (220) in a reactive quenching oil from the nitrification temperature. The reactive quenching oil comprises at least one of S, P, B, Mo and W. Thereby, the quenching additionally comprises coating (222) of the nitrided steel article by a solid lubricant comprising at least one of S, P, B, Mo and W. An apparatus for manufacturing of steel articles, a quenching oil and a steel article produced by the method are also disclosed.

A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42<2<43 and a peak value PMg.sub.2SiO.sub.4 of Mg.sub.2SiO.sub.4 in the form of forsterite, observed in a range of 35<2<36 of both more than 0 and satisfying a relationship PTiNPMg.sub.2SiO.sub.4, in thin-film X-ray diffraction analysis; and an iron loss W.sub.17/50 of 1.0 W/kg or less.

A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42<2<43 and a peak value PMg.sub.2SiO.sub.4 of Mg.sub.2SiO.sub.4 in the form of forsterite, observed in a range of 35<2<36 of both more than 0 and satisfying a relationship PTiNPMg.sub.2SiO.sub.4, in thin-film X-ray diffraction analysis; and an iron loss W.sub.17/50 of 1.0 W/kg or less.

A method and a system for cooling treating metal parts exiting a nitriding/nitrocarburizing treatment in molten salt baths, comprising a cooling chamber in direct relation with a nitriding/nitrocarburizing station for receiving parts therefrom; a gaseous nitrogen feeding unit connected to the cooling chamber and configured to create an inert atmosphere within the cooling chamber; and a screened transfer path between the nitriding/nitrocarburizing station and the cooling chamber; wherein after exiting molten salt baths of the nitriding/nitrocarburizing station, the treated parts are transferred to the cooling chamber through the screened transfer path, and cooled therein to a minimum temperature above a temperature at which salts congeal.

A method and a system for cooling treating metal parts exiting a nitriding/nitrocarburizing treatment in molten salt baths, comprising a cooling chamber in direct relation with a nitriding/nitrocarburizing station for receiving parts therefrom; a gaseous nitrogen feeding unit connected to the cooling chamber and configured to create an inert atmosphere within the cooling chamber; and a screened transfer path between the nitriding/nitrocarburizing station and the cooling chamber; wherein after exiting molten salt baths of the nitriding/nitrocarburizing station, the treated parts are transferred to the cooling chamber through the screened transfer path, and cooled therein to a minimum temperature above a temperature at which salts congeal.

A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42<2<43 and a peak value PMg.sub.2SiO.sub.4 of Mg.sub.2SiO.sub.4 in the form of forsterite, observed in a range of 35<2<36 of both more than 0 and satisfying a relationship PTiNPMg.sub.2SiO.sub.4, in thin-film X-ray diffraction analysis; and an iron loss W.sub.17/50 of 1.0 W/kg or less.

A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42<2<43 and a peak value PMg.sub.2SiO.sub.4 of Mg.sub.2SiO.sub.4 in the form of forsterite, observed in a range of 35<2<36 of both more than 0 and satisfying a relationship PTiNPMg.sub.2SiO.sub.4, in thin-film X-ray diffraction analysis; and an iron loss W.sub.17/50 of 1.0 W/kg or less.