Turbocharger, having a steel material for high-temperature applications

An exhaust-gas turbocharger, comprising:

• a turbine impeller;
• a turbine housing having a receiving region, disposed centrally with respect to a turbine housing axis, for said turbine impeller of the exhaust-gas turbocharger, said turbine housing having at least one turbine spiral duct tapering in a helical shape toward said receiving region for said turbine impeller;
• a wastegate valve with a spindle arm and a flap plate disposed on said spindle arm or a variable exhaust-gas guiding device with bearing disks and guide vanes, disposed in said turbine housing;
• and
• at least one component selected from the group consisting of said turbine housing, said spindle arm and said flap plate, and said bearing disks and said guide vanes, arc formed from a steel material for high-temperature applications, said steel material having a material composition containing iron, Fe, and at least the following alloy constituents in amounts within stated limits in percent by weight:
• carbon, C:
• 0.4-0.5%;
• silicon, Si:
• 1.25-1.75%;
• manganese, Mn:
• 3.0-12.0%;
• chromium, Cr:
• 19.5-20.5%;
• nickel, Ni:
• 5.0-6.0%;
• niobium, Nb:
• 1.00-1.5%;
• wherein said steel material contains at least five of further alloy constituents in proportions up to at most with stated amounts in percent by weight:
• tungsten, W:
• up to 0.6%;
• vanadium, V:
• up to 0.12%;
• copper, Cu:
• up to 0.25%;
• cobalt, Co:
• up to 1.0%;
• sulfur, S:
• up to 0.03%;
• and
• phosphorus, P:
• up to 0.04%.