Evaluation of the Fatigue Strength of Sintered Steel Based on Fracture Mechanics
- Publisher: 日本機械学会
Fatigue Strength | Sintered Steel | Critical Crack Length | Fracture Mechanics | Gear
mesheuropmc: technology, industry, and agriculture
This paper deals with an evaluation of the fatigue strength of sintered steel based on linear fracture mechanics. The fatigue crack growth is measured with bend test specimens of Fe-Cu-Cr sintered steel of various densities. From this result, the fatigue strengths of the specimens with initial length of crack a at the life N are calculated, and they are shown as N-S-A curves. A model, which has an initial crack at the surface but is homogeneous and has no internal flaws, is introduced to analyze the fatigue lives of sintered steel. The initial length of the crack basically depends on the flaw size of sintered steel, and it can be used as an index to evaluate the effect of flaws on the fatigue strength. The initial lengths of cracks are estimated from the N-S-A curves and the fatigue test results. The lengths are 165 to 251 μm for the bend test specimen of 6.6 to 7.0 g/cm3 density.