某发电厂翻车机重调机大臂裂纹原因分析

Cause Analysis of Heavy Adjustable Arm of Car Dumper in a Power Plant

通过宏观检查、化学成分分析、金相组织检验和结构有限元模拟计算,对某发电厂翻车机重调机大臂裂纹产生的原因进行了分析。结果表明:由于原部件中存在较多的夹杂物破坏了金属材料的连续性,严重削弱了金属的塑性和强度。因焊接和结构特点,出现应力分布不均匀且明显的局部应力集中现象。大臂在服役过程中,在薄弱部位产生裂纹,并加速裂纹的扩展,最终导致部件失效。

By macroscopic examination,chemical composition analysis,metallographic structure examination and finite element simulation calculation for structure,the reasons for the crack of heavy adjustable arm of a car dumper in a power plant were analyzed.The results show that the plasticity and strength of metal weakens seriously because lots of inclusions in the original parts damage the continuity of metal material.Due to the welding and structural features,the phenomena of uneven stress distribution and obvious local stress concentration appear.The crack occurs in the weak parts during the service process of heavy adjustable arm and the propagation of the crack accelerates,which can eventually result in the failure of the components.