۱٫ Introduction

۲٫ Case Study

۳٫ Experiment Analysing

۴٫ Analysis and Discussion

۵٫ Conclusion

References

Screw mechanism fixing bolt fracture failure of a 500kV circuit breaker spring mechanism running process. By analyzing the installation position and operating environment, and by means of chemical analysis, metallographic examination and other means, the microstructure macro and micro fracture morphology of the fracture bolt were analyzed. The results show that the surface of the bolt is hydrogen-rich and produces hydrogen embrittlement during surface treatment.

Introduction

The circuit breaker is one of the most widely used high-voltage electrical equipment in various substations, and is a switching device for closing, carrying and breaking line current 1. The circuit can be automatically cut off to prevent the scale of the accident from further expanding when the power line and motor are faulty, so that all electrical equipment in the power system are protected from damage 2. The failure of the operating mechanism of the circuit breaker will have an impact on the stable operation of the power system, causing serious safety hazards. In the event of a system failure, the circuit breaker operating mechanism may refuse to expand the power outages 3,4. In the process of manufacture and installation of circuit breakers, the bolts are often used to form detachable joints.