The material behavior of the standard bearing steel SAE 52100 and the heat resistant bearing steels M50, M50 NiL, and Cronidur 30 as a function of the operational temperature has been investigated. The reduction in rolling contact fatigue strength due to a temperature rise was found to be significantly higher than the reduction of hardness. The mechanism of heat generation due to the bearing operation induces a temperature distribution, which makes it necessary to distinguish between the temperature ruling the subsurface fatigue processes and a higher temperature dominating the surface originated damage initiation.

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Walzbeanspruchte Teile, wie Zahnrlder und Walzlager, unterliegen ganz charakteristischen Beanspruchungen, wie sie in anderen technischen Anwendungen nicht vorkommen. Diese besonderen Bedingungen und ihre Auswirkungen auf die Beanspruchungsverhaltnisse und das Werkstoffverhalten werden ausfuhrlich beschrieben. Vor allem Ingenieuren, die weniger mit dem Thernenkomplex Walzerrniidung und -verschleil3 vertraut sind, sol1 eine ubersichtliche und gestraffte Einfuhrung in dieses Gebiet gegeben werden. Hierzu werden die wichtigsten EinfluRgroRen auf das Verhalten walzbeanspruchter Bauteile, der Ablauf einer eventuellen Schadensinitiierung und die Erscheinungsbilder verschiedener Ausfallsursachen dargestellt. An Beispielen wird gezeigt, wie sich aus der Analyse der Schadigungsablaufe Abhilfemarjnahmen herleiten lassen. Die Literaturhinweise sind so gewahlt, darj sich der interessierte Leser in die einzelnen Themengebiete selbstandig weiter vertiefen kann.Machine parts subjected to rolling contact fatigue, i.e. gears or rolling element bearings, are exposed to a very particular stressing condition. No comparable condition will occur for other technical applications. These typical conditions and their effects on the material behaviour are described comprehensively. An introductional overview for this area of technical knowledge is given, in particular for engineers not so much experienced with respect to this matter. The most important phenomena influencing the behaviour of parts subjected to rolling contact fatigue are presented as well as the physics of damage initiation and the appearance of damaged parts. It is demonstrated exemplarily, how the analysis of the damaging processes can be used to take counter measures. The referencing to the public literature has been done in a way to enable the reader to easily find material for a further improvement of his knowledge for particular items.

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The detrimental influence of inclusions on rolling contact fatigue behaviour of bearing steel is well known and empirically described. Yet only a few publications exist where the effect of inclusions is investigated analytically. This paper presents a new method to describe the influence of inclusions based on a mechanical analysis.