变速箱齿轮低载强化微观机理的初步研究  

Microcosmic Mechanism for Strengthening Low-amplitude Load for Automobile Transmission Gear

作　　者：卢曦[1] 郑松林[1] 

机构地区：[1]上海理工大学机械工程学院,上海200093

出　　处：《机械科学与技术》2007年第10期1312-1316,共5页Mechanical Science and Technology for Aerospace Engineering

基　　金：国家自然科学基金项目(50375101);上海市教育委员会重点科研项目(06ZZ35和07ZZ86)资助

摘　　要：疲劳试验表明工艺强化后的高强度变速箱齿轮经过低载强化,其单齿弯曲疲劳强度和疲劳寿命还能够得到一定程度的提高,而且疲劳寿命提高的幅度远大于疲劳后强度的提高幅度。本文参考未经过工艺处理的低强度前梁的低载强化微观分析结果,利用SEM和TEM对某汽车变速箱齿轮低载强化微观机理进行了初步研究,力图从微观上揭示工艺强化后高强度齿轮低载强化的成因和机理。结果表明,适当的强化载荷能够使高强度齿轮的疲劳扩展区域增加、裂纹扩展间距下降,低载强化使齿轮的微观组织得到进一步的锻炼、强度和硬度有所下降,但微观组织的整体机械性能得到提高。Fatigue experiments show that the single tooth bending fatigue strength and fatigue life of the highstrength transmission of an automobile gear can be increased after it is strengthened with low-amplitude load, but the increase of its fatigue life is far greater than that of its fatigue strength. Taking as reference the microcosmic analysis results of the low-strength front axle of an automobile, which has not strengthened with low-amplitude load, we study the microcosmic mechanism for strengthening the low-amplitude load for the transmission gear of an automobile using the scanning electronic microscope and the transverse electromagnetic microscope. The study results show that the high-strength transmission gear after appropriate strengthening with low-amplitude load has wider fatigue propagation area and lower interval of fatigue crack propagation. The strength and hardness of its mierostrueture decrease somewhat, but its whole mechanical performance increases.

关 键 词：低载强化 微观机理 疲劳强度 疲劳寿命 变速箱齿轮 

分 类 号：U463.3[机械工程—车辆工程]