摘要
采用改进型楔形张开加载试样,研究了高强度螺栓基材42CrMo钢在沿海自然盐雾环境中的应力腐蚀规律,获得了42CrMo材料的应力腐蚀门槛值95.5MPa·■和裂纹扩展速率1.35×10-9 m/s。基于断裂力学提出了螺纹根部应力强度因子的计算方法,并给出了高强度螺栓应力腐蚀开裂风险判据。研究表明,建立的判据可有效用于自然盐雾环境中高强度螺栓产品的应力腐蚀开裂安全性评估。同时发现螺栓工作应力以及微裂纹深度的增加,均会增大螺栓应力腐蚀开裂的风险。
Modified wedge opening loading(WOL)specimens were tested in seacoast environment to study the stress corrosion cracking(SCC)behavior of 42 CrMo steel,which was widely used for manufacturing high-strength bolts.The results showed that the threshold stress intensity factor KISCC was 95.5 MPa·■and the crack propagation rate was 1.35×10-9 m/s.The mathematic model based on fracture mechanism was applied for calculating the stress intensity factor in the root of the thread grooves.The risk assessment criterion of SCC was established.The results showed that the proposed criterion could effectively evaluate the safety of high-strength bolts.It was found that the risk of SCC was more severe with increasing working load and initial crack depth.
作者
居龙
冯超
赵劲彪
张国栋
JU Long;FENG Chao;ZHAO Jingbiao;ZHANG Guodong(Beijing Institute of Space Launch Technology,Beijing 100076,China)
出处
《腐蚀与防护》
CAS
北大核心
2019年第9期644-649,共6页
Corrosion & Protection
基金
中国运载火箭技术研究院质量提升工程项目(ZLTSGC-2015)
关键词
高强度螺栓
应力腐蚀开裂
风险评估
high strength bolt
stress corrosion cracking
risk assessment
