30CrMnSiNi2A双头螺栓断裂失效分析  

Failure Analysis of Fractured 30CrMnSiNi2A Stud Bolt

作　　者：韩露[1] 刘春立[1] 王影[1] 谢国君[1] 卢克非 

机构地区：[1]航天材料及工艺研究所,北京100076

出　　处：《宇航材料工艺》2014年第6期61-67,共7页Aerospace Materials & Technology

摘　　要：文摘分离装置静力试验后发现连接两个舱体的双头螺栓中有7件发生断裂,螺栓表面进行了达克罗处理。通过失效分析及相关试验综合分析认为,分离装置上7件螺栓的断裂性质均为延迟性脆性断裂,断裂机理为氢脆。导致发生氢脆断裂的原因除螺栓材料及组织具有较高的氢脆敏感性外,主要与静力试验过程中长时间包覆湿泥有关;另外,原材料氢含量控制及达克罗涂层工艺处理虽然有效避免了产品表面处理过程中带来的氢脆隐患,但是若使用环境中存在水及腐蚀性介质Cl、S时,产品在拉应力作用下仍可能发生氢脆延迟断裂而导致严重后果。Seven stud bolts bending two cabins were found fractured after the separation device being static test- ed. The surface of bolts was done by Dacromet treatment. Observation on fracture surface and analysis of experiment all indicate property of delayed brittle fracture caused by hydrogen embrittlement. Besides the bolt material＇ s high susceptibility to hydrogen embrittlement, the long time wet coating on bolt during testing largely led to the fracture. A- nalysis indicates that high tensile steel-made item after Dacromet coating treatment is still subject to hydrogen embrit- tlement fracture that causes serious consequence under tensile stress in circumstance where water and corrosive medi- um such as Cl, S exists although Dacromet coating treatment effectively prevent the item from hydrogen embrittlement in surface processing period. This conclusion may serve as precaution to those who design and use high tensile steel under similar circumstance.

关 键 词：30CRMNSINI2A 双头螺栓 达克罗 氢脆 电化学腐蚀 

分 类 号：TB31[一般工业技术—材料科学与工程]