Abstract: A rotor for an electric motor according to the invention comprises a substantially cylindrical core, conductive rods and two short-circuit rings. The cylindrical core is formed from a core material and provided with a plurality of longitudinal grooves which extend substantially in the direction of the cylinder axis. The conductive rods are formed from an electrically conductive material and are provided in the longitudinal grooves of the cylindrical core. The two short-circuit rings conductively connect the axial ends of the conductive rods to one another. A diffusion layer extends between the conductive rods and the cylindrical core. The diffusion layer comprises a diffusion material.

Abstract: A method for the production of steels is provided. A heat treatment is carried out, in which the steel is hardened in water twice at different high temperatures, and subsequently subjected to an annealing treatment. It has been shown that the steel 26NiCrMoV14-5 has a high subzero toughness. In one aspect, the steel is usable down to a temperature of at least minus 170° C.

Abstract: The invention relates to a turbo machine comprising a housing. Said turbo machine is designed especially as a turbo compressor for use at low temperatures, the housing preferably being made of a cold-resistant material that has a martensitic structure.

Abstract: A rotor for an electric motor according to the invention comprises a substantially cylindrical core, conductive rods and two short-circuit rings. The cylindrical core is formed from a core material and provided with a plurality of longitudinal grooves which extend substantially in the direction of the cylinder axis. The conductive rods are formed from an electrically conductive material and are provided in the longitudinal grooves of the cylindrical core. The two short-circuit rings conductively connect the axial ends of the conductive rods to one another. A diffusion layer extends between the conductive rods and the cylindrical core. The diffusion layer comprises a diffusion material.

Abstract: A compressor unit including a centrifugal compressor for compressing a gas and an electric motor with a stator and a rotor for driving the compressor. The compressor and the electric motor are accommodated in a common gastight housing, provided with a gas inlet and a gas outlet. The stator is accommodated in a separate stator space which is delimited by a wall section, surrounding the stator, of the housing, a gastight partition which extends freely between the stator and the rotor of the electric motor, and at least one end wall which extends between the partition and the housing of the compressor unit. The partition is of a material of such high strength that it remains clear of the stator and the rotor under working pressures of the gas.