摘要
某螺栓材料牌号为0Cr_(17)Ni_(4)Cu_(4)Nb(17⁃4PH),螺栓经淬回火热处理工艺表面涂镀锌处理,在设备上安装并施加紧固应力,次年装船投入海洋环境使用,两年半后检查发现螺栓断裂。对断裂螺栓材料的力学性能、显微组织和硬度、断口形貌及化学成分进行了分析和检验。结果表明:螺栓表面涂层氢含量偏高,以及材料强度高、氢脆敏感性大是导致螺栓发生氢脆断裂的主要原因。服役过程中,紧固应力作用于螺纹段表面,导致螺栓表面涂层中的氢逐渐向附近的螺纹根部扩散并富集,局部氢含量达到氢致开裂的临界浓度后,导致螺栓发生氢脆断裂。
The material trademark of one bolt was 0Cr_(17)Ni_(4)Cu_(4)Nb(17⁃4PH).The surface of bolt was coated with zinc af⁃ter quenching and tempering heat treatment.Then it was installed on the equipment and the fastening stress was applied.In the next year,the equipment was shipped and put into marine environment.The fracture of bolt was observed after service for two and half years.The mechanical properties,microstructure,hardness,fracture morphology and chemical composition of the bolt materials were analyzed and tested.The results showed that the hydrogen content in surface coating was high.The high material strength and sensitivity to hydrogen embrittlement were the main reason to cause hydrogen embrittlement fracture of the bolt.In the process of service,the fastening force was applied onto the surface of the thread segment,which resulted in the diffusion and enrichment of hydrogen in the bolt surface coating to the nearby root of the thread.When the local hydrogen content reached the critical concentration of hydrogen⁃induced cracking,the hydrogen embrittlement fracture occurred in the bolt.
作者
朱姣
钟振前
于学亮
李杰
ZHU Jiao;ZHONG Zhenqian;YU Xueliang;LI Jie(National Analysis Center for Iron and Steel,Beijing 100081,China;University of Science and Technology Beijing,Beijing 100083,China)
出处
《物理测试》
CAS
2022年第2期57-63,共7页
Physics Examination and Testing
关键词
螺栓
氢脆
氢脆开裂
bolt
hydrogen embrittlement
hydrogen embrittlement cracking
