某机翼盖板用30CrMnSiNi2A钢螺钉在装配后的存放期间发生了断裂,通过断口宏微观分析、显微组织分析和氢含量测定进行了失效分析;并提出了工艺改进措施.结果表明:螺钉的失效模式为氢脆断裂,氢脆的原因与其材料强度和氢含量过高有关;在根据标准规定除氢工艺的基础上,将螺钉的强度降低到合适的水平,是预防和控制高强度螺钉氢脆的有效措施.

Failure analysis on a 30CrMnSiNi2A steel bolt used for a wing cover plate which fractured huring storage after assembly was carried out by macro and micro observation of the fracture surface,microstructure inspection and hydrogen content test.The improvement measure was introduced.The results show that the failure mode of the bolt was hydrogen brittle fracture.The reason of hydrogen brittle fracture was the over-high material strength and hydrogen content.Decreasing the strength of the bolt to a proper level was a valid measure to prevent and control hydrogen brittle fracture of the high strength bolts based on the standard dehydrogenation process.