Abstract: A method for the production of a forged piston for an internal combustion engine, having a combustion depression provided on the piston head. The piston is formed from a first tube-shaped unmachined part made of oxidation-resistant steel, having at least one join surface, and a second cylindrical unmachined part made of hot-forgeable steel, having at least one join surface. The join surface of the first unmachined part is shrunk onto the join surface of the second unmachined part. The two unmachined parts are formed to produce a piston blank, by means of forging, causing at least the combustion depression to be formed from oxidation-resistant steel. Subsequently the piston blank is finished via machining to produce a piston ready for installation in the internal combustion engine. Simplified and cost-effective production of a piston having a reduced tendency to oxidize at the edge of the depression, and improved protection against wear caused by erosion is achieved.

Abstract: A method for the production of a forged piston for an internal combustion engine, having a combustion depression provided on the piston head. The piston is formed from a first cylindrical unmachined part having at least one flat face made of oxidation-resistant steel and a second cylindrical unmachined part having at least one flat face made of hot-forgeable steel, with the same diameters (d), in each instance. The two unmachined parts are formed to produce a piston blank by means of forging, causing the combustion depression to be formed from oxidation-resistant steel. Subsequently the piston blank is finished via machining to produce a piston ready for installation in the internal combustion engine.

Abstract: According to the invention a light metal cylinder liner with a surface which facilitates the connection with the surrounding cast material may be produced, whereby the cylinder liner is produced by means of a lost-foam method with a form for production of the cast foam model having a structured surface with height variations of 0.8 to 5 mm, said structuring being for example grooves or longitudinal elevations.

Abstract: The invention relates to a cooled ring carrier that is cast into a piston for internal combustion engines. According to the invention, the zone of the ring carrier facing the cooling channel is coated thereby preventing air from escaping from the cooling channel through the ring carrier material to the melt during alfination of the cooled ring carrier, and forming oxides.

Abstract: The aim of the invention is to produce a light-alloy bearing bush with a rough external surface. To achieve this, particles, which are subsequently surrounded in part by the molten melt, are applied to the surface of the casting mould. When the bearing bush is released from the mould, the particles remain in said bush and are subsequently removed from the bearing bush preform either mechanically or by being dissolved in liquid.

Abstract: A cooled ring carrier assembly for the piston of an internal combustion engine, comprising a metal-sheet cooling duct welded to a ring carrier. The cooling duct is press-fit into the inwardly-pointing surfaces of the ring carrier prior to welding. The angle between the inwardly pointing surface of the ring carrier, to which surface metal-sheet cooling duct is welded, and the metal-sheet cooling duct is smaller than 45.degree.. This allows the cooling duct to be press fit into the ring carrier rather than being shrunk in by temperature differences between the ring carrier and cooling duct.

Abstract: A light-metal piston has a sheet-metal cooling channel integrally cast in the piston head. In order to improve the heat transfer between the piston material and the cooling channel and to reduce the manufacturing costs of the cooling channel, the channel has a narrow slit, which allows oil to pass, extending along at least part of the channel wall.