Improving on the rolling contact fatigue life and mechanical behaviors of bearing steel by nitrogen plasma immersion ion implantation 氮等离子体浸没离子注入技术改善轴承钢滚动接触疲劳寿命和机械性能的研究
Ceramic bearing which has thermostable , anti - corrosive , the self lubrication good character . widely applied in aviation , astronautics , national defense . rolling contact fatigue is one of the main inactivation types of bearing 陶瓷轴承,具有耐高温、耐腐蚀、自润滑性好等优点,广泛应用于航空、航天、国防等领域,其主要失效形式为滚动接触疲劳,研究和改善润滑剂的抗疲劳性能是提高轴承滚动接触疲劳寿命的重要途径。
At present an important subject is researched on prediction methods of the initiation life of rolling / sliding contact fatigue of surface hardening layer based on shakedown theories under cycle contact loading for the strategies of applications of contact element , such as gears , bearings , and railroad rails 接触体表面强化(喷丸、涂层)层的疲劳裂纹萌生寿命的研究，是当前齿轮、轴承等接触件失效分析中的前沿课题。它具有重要而广泛的工程背景。
The changing carbon potential carburization - hot oil matrempering technology of helical bevel gear for automobile driven axle is introduced in this article . the board test and production application show that the technology not only quenchs directly gear after carbrization , but also decreases the heat treatment deformation and raises the contact fatigue life of gear 介绍了汽车驱动桥螺旋锥齿轮的变碳势渗碳一热油分级淬火工艺，台架试验及生产应用表明，该工艺与专用渗碳淬火挂具相结合，不仅可实现齿轮渗碳后直接淬火，而且热处理变形小，齿轮接触疲劳寿命也有所提高。
2 , the friction coefficient at the pitch point is not a monotonic quantity of the rational speed or the load , instead of having a maximum value . and the value of the friction coefficient is very small , its order of magnitude only being 10 - 3 . so , it is reasonable that the friction force on teeth surfaces are ignored when the gear - driven contact fatigue strength is designed 2 、当轮齿在节点啮合时，随着转速或载荷的变化，齿面摩擦系数并非呈单调变化，而是存在极值点;节点啮合处的齿面摩擦系数很小，其数量级为10一， ，因此在做齿轮强度设计时，忽略齿面摩擦力的影响是有理论根据的。
In this paper , select li 3 # and grease 7014 as basis grease . select nano diamond and sio _ 2 are selected as additives , design 14 recipe using k and l10 as appraise norm study the dose of nano particle to the effect of contact fatigue of ceramic and steel friction has the conclusion that proper quantities nano particle which put in two grease can improve the contact fatigue life of ceramic using sem and edax , nano particles fatigue resistance mechanism are analyzed . which can improve the contact fatigue life of ceramic and steel friction 本文选用3 #通用锂基脂和7014号宽温航空润滑脂作为基础脂,选取纳米金刚石粉和纳米二氧化硅微粒作为添加剂,设计了14种配方。利用威布尔斜率k和额定寿命l10作为评价指标,研究了纳米微粒的用量对陶瓷球/钢副的接触疲劳寿命的影响,得出在所选两种基础脂中添加合适用量的纳米微粒添加剂可以提高陶瓷球的接触疲劳寿命。利用sem和edax ,初步揭示了纳米微粒提高陶瓷/钢副滚动接触疲劳的机理。
Investigations showed that one of the most important characteristics of pearlitic materials is the decrease of ratcheting rate , the plastic shakedown capability , and the memory and recovery of the accumulated plastic strain under asymmetrical stress cycles . it was found that the interaction between phases plays an important role in the mechanical behavior of pearlitic materials , such as wearability and contact fatigue life 珠光体材料的重要特性之一是在非对称应力循环下循环蠕变速率的减缓并趋于塑性安定以及材料对循环蠕变史的记忆与恢复；同时珠光体材料的宏观力学性能与其细观结构密切相关，在很大程度上取决于珠光体材料的微结构及其相互作用。
Research and improvement of contact fatigue resistance of grease and additives are important ways to increase the bearing life with the development of nano tribology , nano particles additives have appear excellent performance , so it is of great theoretical and practical significances to carry out studies of the contact fatigue resistance of such additives 随着纳米摩擦学的发展,纳米级固体微粒添加剂表现出优良性能。因此研究纳米级固体微粒添加剂来改善润滑剂的抗疲劳性能具有重要的理论意义和实用价值。
After being improved , the gear surface contact fatigue strength obeys weibull distribution and stress obeys normal distribution , the gear bottom bend fatigue strength and stress obey logarithm normal distribution , according to the relation of average safe rate and reliability , then the gear strength reliability design and check equations can be deduced 将齿面接触疲劳强度按威布尔分布、应力按正态分布处理，将齿根弯曲疲劳强度和应力均按对数正态分布处理，再根据平均安全系数和可靠度之间的关系，推导出了齿轮强度可靠性设计和校核公式。
In this thesis , the strain - hardening model of contact surface layer , the numerical theories and computational methods for shakedown analyses of contact body are systematically studied and applied to the aero - gear . the mentality is that the effects of the surface hardening and contact fatigue on contact surface layer under cycle contact loading are investigated by using shakedown analysis methods considering in a quantitative way the details of stress - inelastic strain responses , residual stress and residual strain computations 在国家“航空基金” 、 “总装预研基金”等课题的资助下，本文以接触体安定分析与接触表面层疲劳裂纹萌生寿命预测一般算法研究为手段，深入、系统研究了接触体安定分析的数值理论和计算方法，全面研究了影响航空齿轮表面强化层失效的原因并提出了齿轮表面强化层裂纹萌生寿命的预测方法。
