Socket Clevis Overview And Causes Of Breakage

In the transmission line, socket-clevis plays the role of suspension insulator string and suspension clamp, which is subjected to large working stress, and its safety performance is very important for the transmission line.

Fracture cause
The stress level of the failed Socket Clevis increased due to the static load tension of the wires and the effect of wind, rain, snow and ice on the wires. At the same time, the steel tower where the failed Socket Clevis is located is near the thermal power plant, and the industrial gases containing corrosive media (such as SO2, H2S, NaCl, etc.) emitted by the power plant for a long time may pass through the not dense galvanized layer on the surface of the casting and directly corrodes the matrix of the casting hardware. There are a large number of surface and core cracks in Socket Clevis, which are characterized by intergranular corrosion and stress corrosion. The sudden fracture of Socket Clevis castings is the result of this dual corrosion failure. On the other hand, the casting defects such as poor spheroidization, porosity and shrinkage in the double Socket Clevis castings also seriously weakened the mechanical properties of the material matrix, thus accelerating the corrosion crack propagation process. Because Socket Clevis castings are subjected to a certain stress for a long time, under the combined action of corrosive environment and stress, crack sources will be generated at the defects on the surface of the castings, and will rapidly expand internally along the grain boundaries, resulting in stress corrosion fracture of Socket Clevis castings.