Schwingfestigkeitsnachweis für innendruckbelastete Common-Rail-Bauteile aus 100Cr6 unter Berücksichtigung hochzyklischer Betriebsbeanspruchungen

The manifold degrees of freedom in setting the injection pressure result in highly cyclic, variable load collectives for high pressure carrying components of a common-rail system during its‘ life. As these parts are safety-relevant, the safety against a fatigue induced fracture must be verified. Detailed knowledge of the fatigue behaviour beyond today’s ultimate number of cycles of the commonly used high strength steel 100Cr6 is required as a result. The necessary experimental characterisation of the fatigue behaviour in dependence of various influencing factors was undertaken in the relevant lifetime area within the scope of this thesis. The experiments were largely conducted using notched specimens on a high frequency piezoelectric ultrasonic testing machine as well as part-like dummies on servo-hydraulic high pressure test stands. A new approach to the fatigue life verification for parts made of 100Cr6 was developed based on these experimental trials. This approach allows an integral fatigue life assessment considering the specific failure mechanisms of the high cycle fatigue and very high cycle fatigue regime.