50CrVA钢弹簧断裂分析

由50CrVA钢绕制的弹簧在服役后发生断裂，采用断口宏观及微观观察，金相组织分析，能谱分析，显微硬度试验等方法对断裂原因进行了综合分析。结果表明，断裂弹簧属氢致脆性断裂，在加工过程中电镀时的电接触损伤是发生氢致脆断的主要原因，同时退铜工艺过程中酸洗过度也是导致氢致脆断的因素。提出改进措施为在电镀过程中，确保电极固定后与簧丝不局部接触，在表面处理工艺中尽可能减少弹簧吸氢环节，同时保证除氢的时间受控。该故障的原因分析及纠正措施可为提高产品质量，加强特种工艺控制，防止类似问题再次发生提供借鉴。

Fracture Analysis of Spring of 50CrVA Steel

A spring of 50CrVA steel was found to have fractured after service for a while. The fracture cause was analyzed by fracture observation, micro-structure examination, energy spectrum analysis, and microhardness testing. The results show that the failure mode of the spring is hydrogen induced brittle fracture, which was mainly caused by the electrical contact damage occurring during electric plating. In addition, excessive acidwashing during the process of decopperization is another factor for the hydrogen induced brittle fracture. The following measures can be taken to prevent thus failure. On the one hand, it should be ensured that spring thread don＇ t contact the electric pole during electric plating. On the other hand, the hydrogen absorbed by the spring should be reduced daring surface treatment and the dehydrogenation time should be prolonged.