Microstructural Investigations of Cracks in Turbine Wheels in Car Engine Turbochargers

Abstract:

The turbine wheel is the most affected element in passenger car turbochargers. In order to meet the requirements for the high temperature corrosion, vibrations and the mechanical resistance in the oxidizing environment of the exhaust gases, the turbine wheel is produced from polycrystalline nickel based superalloys, Inconel 713C in the as-cast condition. In this work the methods and results of turbine wheel failure analysis are presented. For this type of research, correlative microscopy, light microscope Axio Imager Z2m (LM), scanning electron microscope Zeiss Ultra Plus with field emission (FESEM) equipped with EDX detector and stereoscopic microscope were used. The results of this work suggest that the Inconel 713C turbine wheel was damaged by two factors: fatigue cracking at low frequencies and grain boundaries oxidation.

• Periodical: Solid State Phenomena (Volume 231)
• Pages: 133-138
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.231.133
• Online since: June 2015
• Authors: Sebastian Krawiec*, Łukasz Krawczyk
• Keywords: Fatigue Cracking, Inconel 713 Alloy, Microstructure, Sample Preparation, Turbine Wheel, Turbocharger

References

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[2] F. Zupanič, T. Bončina, A. Križman, Stucture of the nickel base superalloy IN 713C after continuous casting, in: Superalloys 2000, T.M. Pollock et al (Eds. ), TMS The Minerals, Metals & Materials Society, 2000, pp.239-246.

DOI: 10.1179/026708302225003640

[3] F. Binczyk, J. Cwajna, S. Roskosz, P. Gradoń, Evaluation of metallurgical quality of master heat IN-713C nickel alloy ingots, Arch. Foundry Eng. 12 (2012) 5-10.

DOI: 10.2478/v10266-012-0099-5

[4] WL 2. 4671 DIN standard. High temperature nickel cast alloy with about 0. 15C-13Cr-6Al-4. 5Mo-2. 3Nb (1984).