新型Fe-C-Cu系粉末锻造双材料连杆不同部位的疲劳性能  

Fatigue Properties of Different Parts of New Fe-C-Cu Powder-Forged Bimaterial Connecting Rod

作　　者：张广为 张广明 毛敏捷 邵静静 李建 ZHANG Guangwei;ZHANG Guangming;MAO Minjie;SHAO Jingjing;LI Jian(School of Mechanical and Automotive,Qingdao University of Technology,Qingdao 266520,China)

机构地区：[1]青岛理工大学机械与汽车工程学院,青岛266520

出　　处：《机械工程材料》2020年第4期52-56,共5页Materials For Mechanical Engineering

基　　金：青岛理工大学新进教师科研启动基金资助项目(C217023)。

摘　　要：基于连杆高疲劳强度要求及胀断工艺,设计了粉末锻造双材料连杆;通过金相检验、扫描电镜及疲劳试验等方法研究了此双材料连杆大头、杆部的显微组织和疲劳性能。结果表明:连杆大头、杆部的显微组织均主要由珠光体、铁素体和纳米富铜相组成,杆部材料中的纳米富铜相数量更多、尺寸更大,此外大头材料中还存在弥散分布的MnS颗粒;杆部材料的平均疲劳强度和疲劳极限均高于大头材料的,喷丸强化后杆部的疲劳性能进一步提高;大头材料中的MnS颗粒会促进疲劳裂纹扩展,从而降低其疲劳强度;喷丸处理使杆部表面层得到强化,从而提高了其疲劳性能。Based on the requirements of high fatigue strength of connecting rod and fracture splitting process,apowder-forged bimaterial connecting rod was proposed.The microstructure and fatigue properties of the big end,rod of the powder-forged bimaterial connecting rod were analyzed by metallographic examination,scanning electron microscope and fatigue test.The results show that the microstructure of the big end and the rod were composed of pearlite,ferrite and nano copper rich phase,and the rod material had more and larger nano copper rich phases.The average fatigue strength and fatigue limit of the rod material were greater than that of the big end material,and the fatigue performance of the rod was further improved after shot peening.The MnS in big end material promoted fatigue crack expansion,which could reduce the fatigue strength,while shot peening could strengthen the surface layer of the rod material and improve its fatigue resistance.

关 键 词：双材料 连杆 粉末锻造 喷丸强化 疲劳性能 

分 类 号：TG317[金属学及工艺—金属压力加工]