A100超高强度钢腐蚀疲劳裂纹扩展拘束效应研究  

Constraint effect on corrosion fatigue crack growth behavior of A100 ultrahigh strength steel

作　　者：李一哲 黄海亮 卞贵学 王安东 王玺 LI Yizhe;HUANG Hailiang;BIAN Guixue;WANG Andong;WANG Xi(Qingdao Branch,Naval Aeronautical University,Qingdao 266041,Shandong,China)

机构地区：[1]海军航空大学青岛校区,山东青岛266041

出　　处：《航空材料学报》2024年第6期90-96,共7页Journal of Aeronautical Materials

基　　金：山东省高等学校“青创团队计划”(2022KJ082)。

摘　　要：超高强度钢被广泛用于制造飞机起落架等主要承力结构,在海洋恶劣环境下服役时易发生腐蚀疲劳失效。由于拘束效应的存在,实验室小尺寸试样与实际结构的疲劳裂纹扩展行为不同。针对不同裂纹深度和试样厚度的单边缺口拉伸试样,开展A100超高强度钢在空气、中性和酸性海水环境下的疲劳裂纹扩展实验。结果表明:随着裂纹深度和试样厚度增大,裂纹尖端拘束水平升高,疲劳裂纹扩展阻力降低,裂纹扩展速率增加;相较于腐蚀环境和拘束效应单独作用,拘束效应和腐蚀环境共同作用会显著增加A100超高强度钢的疲劳裂纹扩展速率;当应力强度因子幅值ΔK=30 MPa·m^(1/2)时,拘束参量与腐蚀疲劳裂纹扩展速率呈现良好的正相关性。相关研究结果可为海洋环境下服役超高强度钢结构寿命评估提供参考。Ultrahigh strength steel has been widely used to manufacture aircraft landing gear and other load-bearing structures,which is prone to corrosion fatigue failure when serving in harsh marine environment.The fatigue crack propagation behavior of small-sized samples in laboratory is different from that of actual structures due to constraint effect.The fatigue crack propagation tests of A100 ultra-high strength steel in air,neutral and acidic seawater are carried out using single edge tension specimens with different crack depths and specimen thickness.The results show that with the increase of crack depth and sample thickness,the constraint level of crack tip increases,the fatigue crack growth resistance decreases,and the crack growth rate accelerates.The combined effect of constrains and corrosion environment significantly accelerate the fatigue crack growth rate of A100 ultrahigh strength steel.As the amplitude of stress intensity factorΔK equals to 30 MPa·m^(1/2),a good positive correlation between constraint parameters and corrosion fatigue crack growth rate can be observed.The relevant research results can provide reference for the service life assessment of ultrahigh strength steel structures in marine environment.

关 键 词：A100超高强度钢 拘束效应 腐蚀疲劳 裂纹扩展 

分 类 号：V215.5[航空宇航科学与技术—航空宇航推进理论与工程]