特高压隔离开关传动连杆的裂痕分析

Crack Analysis of Transmission Connecting Rod of UHV Disconnecting Switch

针对特高压隔离开关传动连杆出现的裂纹问题,对操作机构传动连杆进行三维建模,并应用有限元软件对传动连杆分合闸过程进行动态仿真,计算分合闸过程中长、短连杆应力分布情况以及各个时刻应力最大值,以检验连杆的安全裕度,分析出现裂痕的原因。随后对连杆材质进行理化检测,分析连杆中相关元素含量,发现连杆材质中Mn元素含量严重超标,Ni元素和Cr元素严重低于标准值。虽然提高材料的强度,满足了硬度的安全裕度,但是材料的延伸率和断面收缩率却明显低于标准值,使其不能形成稳定和均匀的常温奥氏体组织,导致隔离开关运行过程中连杆出现裂痕。

Aiming at the crack problem in the transmission connecting rod of the UHV disconnecting switch,the three-dimensional modeling of the operating mechanism transmission connecting Rod was carried out,and the finite element software was used to dynamically simulate the transmission connecting Rod closing process.The long and short process of the opening and closing process was calculated.The stress distribution of the connecting rod and the maximum value of the stress at each moment were used to verify the safety margin of the connecting rod.Physical and chemical testing of the connecting rod material was carried out to analyze the content of related elements in the connecting rod.It was found that the content of Mn in the connecting rod material was seriously exceeded,and the Ni element and Cr element were seriously lower than the standard value.Although the strength of the material was improved to meet the safety margin of hardness,the elongation and reduction of area of the material were obviously lower than the standard value,which made it unable to form stable and uniform normal temperature austenite structure,resulting in cracks in the connecting rod during the operation of the disconnecting switch.