A nickel- and chrome-rich highly heat-resistant, austenitic iron based alloy. The alloy exhibits an improved fine dendritic carbide structure and can withstand repeated thermal elongation and strain which is particularly important for an exhaust-gas turbocharger component exposed to exhaust gas flow, such as a turbine housing. The alloy also guarantees very good thermo-mechanical fatigue (TMF) loading performance. A thermal cracking problem of the component is significantly reduced. The alloy is influenced by the relationship between the elements nickel, niobium, cerium and vanadium. The invention further concerns a method for prevention of crack formation and for minimizing oxidization in a turbocharger turbine housing.

A method of refurbishing worn diaphragm rails for turbo machines. This method comprises machining the worn part of the diaphragm rails such that a clean and geometrically exact machined surface is achieved. Welding one or more layers on these machined surfaces builds up a cladding that overtops the nominal dimensions of new diaphragm. The method further comprises machining the cladding such that it has the nominal dimensions of a new diaphragm.

Bearing bushings which are exposed to highly elevated temperatures during operation, corresponding high-temperature-resistant bearing bushings and exhaust-gas turbochargers having at least one such bearing bushing, include an iron material having a material composition which, apart from iron, has at least carbon, silicon, manganese, nickel, chromium, molybdenum and tungsten alloy constituents in certain amounts. This material composition ensures sufficient temperature resistance and self-lubricating properties with simultaneously good machining properties and a moderate price.

A turbine housing for a turbocharger has a plurality of interconnected housing parts. A central, one-piece contoured component that is constructed as a cast component or a forged component is provided on that side of a spiral channel which faces away from a bearing housing attachment flange in the turbine housing. The contoured component has a wall region of the spiral channel, a boundary wall of an exhaust gas inlet gap and a sealing contour region. The contoured component is connected to its adjacent housing parts, which are at least partly constructed as sheet metal molded parts, so as to form the turbine housing.