40Cr六角螺栓断裂失效分析  

Fracture failure analysis of 40Cr hexagon bolt

作　　者：王园园[1] 刘海波[1] 张林涛[1] 王君[1] 许宗凡 

机构地区：[1]国家标准件产品质量监督检验中心,浙江海盐314300 [2]中国航空工业标准件制造有限责任公司,贵州贵阳550014

出　　处：《金属制品》2015年第5期64-66,共3页Metal Products

摘　　要：螺栓安装不久后断裂。采用扫描电子显微镜、光学显微镜、直读光谱分析仪、测氢仪、硬度计对断裂螺栓断口的宏观和微观组织形貌、硬度、化学成分、氢含量进行检查和分析。结果表明,螺栓断裂失效的原因主要是螺栓加工过程中采用了酸洗,并且酸洗渗氢后没有除氢,使螺栓氢含量过高造成氢脆隐患,在安装应力的作用下引发氢致延迟断裂。建议10.9级螺栓表面处理前,不进行酸洗处理;如果高强度螺栓进行电镀,在电镀后4 h内必须进行除氢处理。Bolt appears fracture soon after installation. SEM,optical microscope,direct-reading spectrograph,hydrogen measuring instrument,hardness tester are adopted to examine and analyze the morphology,hardness,chemical composition,hydrogen content of fracture bolt surface micro and macro structure. Result shows： adopting pickling during the making process of the bolt is the main reason to cause bolt fracture failure,because hydrogen is not eliminated after pickling hydrogen permeation,make bolt hydrogen content excessive high,and cause hydrogen embrittlement risk,trigger hydrogen induce delay fracture under the function of installation stress. It is advised that pickling should not be carried out before the surface treatment of 10. 9 grade bolt; if high strength bolt need to be electroplated,dehydrogenation must be conducted within 4 hours after electroplating.

关 键 词：40CR钢 六角螺栓 酸洗 氢脆 应力 

分 类 号：U464[机械工程—车辆工程]