Development of Reliability Test of DI Diesel Piston Combustion Bowl Rim

摘要

In the fatigue test of non-iron materials, clear fatigue limits don't appear. In using these materials, we should distinguish between low-cycle (10{sup}3-10{sup}5) and high-cycle fatigue (over 10{sup}6). In most cases, the problem of the former is bigger than that of the latter, because the former is greater than the yield strength and can't be evaluated except by engine running test. On the other hand, it is required this problem should be estimated and taken measures before engine tests and high quality products should be provided. This paper is the example study on the method of normal and accelerated rig-test of diesel engine piston bowl rim crack in consideration of low cycle fatigue. Finally, the equation which determines the number of its crack cycle in engine test could be derived, and the factors affecting on its crack was clarified.