【摘要】 本文以中型货车发动机曲轴为对象,研究了球铁曲轴弯曲疲劳强度的特点。结果表明,轴颈圆角表面粗糙度在Ra1.6～Ra0.4范围内时,球铁曲轴的弯曲疲劳性能无显著变化;同一曲轴上各曲拐疲劳强度存在差异;铸态下球铁曲轴圆角强度的分散性大约是锻钢的3～4倍,强化后这种分散性可减小一半以上。球铁曲轴的上述特点主要由球铁材料本身的特性和毛坯浇铸时凝固冷却不一致所造成的。更多还原

【Abstract】 Some characteristics of bending fatigue strength of nodular cast iron crankshaft are studied based on the tests on crankshaft of a medium truck engine. It was found that the bending fatigue strength of nodular cast iron crankshafts did not vary significantly with the crankpin fillet surface roughness within the rang of Ra 1.6-Ra0.4. Fatigue strength was different from crank to crank even in one crankshaft. The scattering band of crank fillet strength of casted nodular cast iron was about 3 ~ 4 times as large as that of the forged steel, but it could be reduced by more than 50% after strengthening. Such behaviors of nodular cast iron crankshaft was thought due to the material characteristics and ununiform solidfication of crank during casting.更多还原