与低合金烧结钢零件形状相对应的后续处理条件最优化研究

为了扩展粉末冶金的业务,改进动态力学性能和搜集这样的数据是必要的.我们长期认为部分扩散粘结合金较适合达到较高的疲劳强度,对于在某些作业条件下的零件的确是这样.然而,现在粉末冶金零件的密度水平在提高.高密度和后续加工的最佳化相结合表明,与部分扩散粘结合金相比,预合金化的材料更适于得到高得多的疲劳强度.于是,开展了一些改善疲劳强度的研究.本文介绍了通过应用喷丸法改善疲劳强度,而且通过分析应力曲线讨论了改善疲劳强度的机制.还讨论了几何形状对应力曲线的影响,其中包括对实际的变速器齿轮的FEM分析,以此来描述每一零件的最佳后续加工方法.对于一个实际的变速器齿轮使用粉末冶金零件的可能性,在这篇论文中,通过用测量嵌进实际变速器齿轮箱中的齿轮的齿根应力计算的安全系数进行了讨论.

Optimization of secondary operations according to geometry of component made of low alloyed sintered steel

In order to expand PP business,the improvement of dynamic mechanical properties and the repertory of such data are necessary.We have thought for long time that partially diffusion bonded alloy is more suitable to achieve higher fatigue strength.It is true for the component under some process conditions.However,the level of density for PP components is improving today.The combination of both high density and optimization of secondary operations showed that pre-alloyed material was more suitable to achieve much higher fatigue strength than partially diffusion bonded alloy.Then some studies to improve fatigue strength were presented. This paper introduces the improvement of fatigue strength by applying shot peening process and discusses the mechanism of improvement of fatigue strength by considering stress profile.The influence of geometry on stress profile has also been discussed,including the FEP analysis of actual transmission gear to describe the optimum secondary operations for each component. The possibility to apply PP components for an actual transmission gear has been discussed in this paper by calculating safety factor with the root stresses measured of the embedded gear in an actual transmission gear box.