分接开关主驱动轴低周疲劳行为及断裂特性  

Low cycle fatigue behavior and fracture characteristics of tap changer main drive shaft

作　　者：周璇 黄耀 杨帆 赵鼎萱 李可尔 于国祥 陈威[1] 蔡和平[1] Zhou Xuan;Huang Yao;Yang Fan;Zhao Dingxuan;Li Keer;Yu Guoxiang;Chen Wei;Cai Heping(State Key Laboratory for Mechanical Behavior of Materials,Xi'an Jiaotong University,Xi'an Shaanxi 710049,China;China Electric Power Research Institute,Beijing 100192,China)

机构地区：[1]西安交通大学金属材料强度国家重点实验室,陕西西安710049 [2]中国电力科学研究院有限公司,北京100192

出　　处：《金属热处理》2022年第12期269-274,共6页Heat Treatment of Metals

基　　金：国家电网有限公司总部科技项目(5200-202058470A-0-0-00)。

摘　　要：针对分接开关主驱动轴球墨铸铁部件,系统研究了其低周疲劳性能及断裂特性。结果表明,EN-GJS-700-2球墨铸铁的疲劳寿命强烈依赖于施加的循环应变幅。进一步研究发现,疲劳寿命主要取决于循环应变幅中的塑性分量,以至于疲劳寿命与循环总应变幅满足Coffin-Manson方程。SEM断口形貌显示,不论是低应变幅还是高应变幅下,球墨铸铁表面处的球状石墨/珠光体界面是疲劳裂纹的优先萌生位置,并呈现出多源特征。在随后的裂纹扩展过程中,高应变幅断口平坦,解理断裂特征明显,难于观察到疲劳条纹。但在低应变幅下,球形石墨和珠光体显著参与塑性变形,疲劳条纹变得明显。Low cycle fatigue properties and fracture characteristics of the main drive shaft of tap changer were systematically studied.The results show that the fatigue life of the EN-GJS-700-2 ductile iron strongly depends on the applied cyclic strain amplitude.It is further found that the fatigue life mainly depends on the plastic component in the cyclic strain amplitude,so that the fatigue life and the total cyclic strain amplitude satisfy the Coffin-Manson equation.SEM fracture morphology shows that the spheroidal graphite/pearlite interface on the surface of ductile iron is the preferred initiation position of fatigue cracks under low or high strain amplitude,and presents multi-source characteristics.In the subsequent crack propagation process,the high strain amplitude fracture is flat,the cleavage fracture characteristics are obvious,and it is difficult to observe the fatigue stripes.However,at low strain amplitude,the spherical graphite and pearlite significantly participate in plastic deformation,and the fatigue stripes become obvious.

关 键 词：球墨铸铁 低周疲劳 疲劳寿命 断口分析 

分 类 号：TG146.2[一般工业技术—材料科学与工程]