铸造缺陷和热处理工艺对球墨铸铁曲轴疲劳强度的影响

Effect of Casting Defects and Heat Treatment Technique on Fatigue Strength of The Crankshaft of Spheroidal Graphite Cast Iron

195型柴油机球墨铸铁曲轴的失效形式 ,主要是疲劳断裂。铸造缺陷 ,尤其是铸造缩松 ,降低了曲轴的疲劳强度。热处理强化工艺中 ,正火和等温淬火、氧氮化 ,尤其是氧氮化处理 ,能提高曲轴疲劳强度。因此 ,改善铸造质量并采用氧氮化是提高曲轴疲劳寿命的有效手段。

Fatigue fracture is the main form of failure of the crankshaft of spheroidal graphite cast iron in 195 model diesel engine.Casting defects,especially porosity,will reduce fatigue strength of the crank-shaft. With heat treatment technigues,normalizing.auslempering and oxynitriding,especially oxynitriding,are capable of increasing fatigue strength of the crankshaft.Therefore,the improvement on casting quality and adoption of the oxynitriding are efficiant means to increase,fatigue life of the crankshaft.