减速机高速轴断裂原因分析

ANALYSIS ON THE FRACTURE CAUSE OF REDUCER HIGH SPEED SHAFT

某热电厂减速机的高速轴在运行中发生断裂,通过对断轴进行宏观检验、化学成分分析、表层能谱分析、硬度检验、金相检验以及力学性能测试,并结合减速机的运行工况进行分析,结果表明,高速轴的制造质量不合格。由于其表面渗氮层中存在大量微裂纹和针状组织,在运行期间,微裂纹发生扩展,造成表层金属剥落,形成应力集中,最终导致高速轴出现疲劳断裂。针对断裂的原因,提出了相应的改进建议。

Fracture occurred during the operation of the reducer high speed shaft in certain power plant. Through macroscopic examination, chemical composition analysis, surface energy spectrum analysis, hardness testing, metallographic examination and mechanical performance test, this paper makes an analysis combining with the operating conditions of the reducer. The results show that the manufacturing quality of the reducer high speed shaft was unqualified. Since there are plenty of micro-cracks and acicular tissues in the surface of the nitriding layer, the micro-cracks spread during operation, which results in surface metal peeling and stress concentration. Finally, this leads to fatigue fracture of the high speed shaft. Aiming at the fracture causes, the paper presents some corresponding improvement suggestions.