M3×10 mm十字槽沉头螺钉断裂分析  

Fracture Analysis of M3×10 mm Cross Groove Countersunk Head Screw

作　　者：刘永生[1] 付明[1] LIU Yongsheng;FU Ming(China Airborne Missile Academy,Luoyang 471009,China)

机构地区：[1]中国空空导弹研究院

出　　处：《热加工工艺》2018年第15期253-255,共3页Hot Working Technology

摘　　要：某发射装置中的1Cr17Ni2钢M3×10 mm十字槽沉头螺钉,在使用中发生断裂。为了确保该发射装置可靠运行,对该螺钉断裂展开了分析和研究。观察了金相组织、测试了硬度,其均符合HB1-206-2002标准要求。通过体视镜对螺钉断口及未断裂螺钉十字槽进行了宏观形貌观察,发现断裂部位存在锈蚀痕迹,而未断裂螺钉十字槽底部已出现裂纹。进一步对断口微观形貌进行了观察与分析,发现断口无明显塑性变形痕迹。能谱分析结果显示,断口区域存在大量Cl-,可判断失效原因为应力腐蚀破坏。建议调整冲压工艺、降低表面拉应力,避免出现应力腐蚀现象,确保发射装置运行可靠性。The 1 Cr17Ni2 steel M3×10 mm cross groove countersunk head screw in a launcher was broken during use. In order to ensure the reliable operation of the launching device, the fracture of the screw was analyzed and studied.metallographic structure was observed and the hardness was tested. They all meet the HB1-206-2002 standard requirements.Through stereoscopic observation of the fracture surface of the screw and the cross groove of the unbroken screw, it is found that there are rust marks in the fracture site, while cracks have been appeared at the bottom of the cross groove of the unbroken screw. The fracture morphologies were observed and analyzed. No obvious trace of plastic deformation is found on the fracture surface. The results show that there is a lot of Cl- in the fracture area, which can judge the failure reason as the stress corrosion damage. It is suggested to adjust the stamping process and reduce the surface tensile stress to avoid the phenomenon of stress corrosion and ensure the reliability of the launcher.

关 键 词：十字槽沉头螺钉 1CR17NI2钢 Cl-离子 应力腐蚀 

分 类 号：TG306[金属学及工艺—金属压力加工]