螺栓头部容易产生断裂.采用硬度试验机、金相显徽镜及氢脆试验等手段对失效的螺栓与未失效的螺栓进行对比分析,结果表明该螺栓的失效为氢致断裂.由于热处理的工艺不当,渗碳层过深,导致过多的氢滞留在螺栓基材的内部,在随后的回火过程中氢不易扩散,是导致螺栓氢脆断裂的主要原因.后续的电镀工艺中未及时进行有效的去氢,更加重了氢脆断裂的风险.%II Is easy for the screws head to be broken. This paper uses hardness tester, metallographic microscope and hydrogen embritttement test to cany out the contrastive analysis lor the failed and the un-taled screws. The test results show that the hydrogen results In screw breaking. Because the heat treatment process Is improper,csrburlzed layer Is too deep,so hydrogen Is not easy to be sent out In tempering process, this Is me main reason of screw breaking. Due to the hydrogen which is not got rid of timely and effectively, the risk of hydrogen embriWement Is Increased during the plating process.
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