LY12CZ铝合金在人工海水中的腐蚀疲劳裂纹扩展行为  

Corrosion Fatigue Crack Growth Behavior of LY12CZ Aluminum Alloy in Atifi cial Seawater

作　　者：黄小光[1] 王黎明 曹宇光[1] 

机构地区：[1]中国石油大学(华东)储运与建筑工程学院,青岛266580

出　　处：《机械工程材料》2015年第6期95-98,104,共5页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51404286);山东省自然科学基金资助项目(ZR2014EEQ018);青岛经济技术开发区重点科技发展计划项目(2013-1-53)

摘　　要：采用腐蚀疲劳试验方法,研究了LY12CZ铝合金在人工海水(3.5%Na Cl溶液)中腐蚀疲劳裂纹的扩展规律,分析了载荷频率、应力比以及人工海水p H对裂纹扩展速率的影响,并借助扫描电镜对其断口形貌进行了观察。结果表明:随载荷频率、人工海水p H的降低,腐蚀疲劳裂纹扩展速率会显著加快,应力比则主要影响腐蚀疲劳近门槛值区的裂纹扩展;在中性人工海水中阳极溶解对裂纹加速扩展起主导作用;随人工海水p H的降低,裂尖氢置换反应加剧,裂尖材料氢损伤对裂纹扩展的加速效应逐渐显现。A corrosion fatigue test was applied to study the corrosion fatigue crack propagation behavior of LY12 CZ aluminum alloy in artifi cial seawater（3.5wt%Na Cl solution）. The infl uences of loading frequency, stress ratio and the p H value of artifi cial seawater on crack propagation rate were analyzed, and the fracture was observed by SEM to study the mechanism of crack propagation. The test results show that when the loading frequency and p H value decreased, the crack propagation rate increased signifi cantly, and the stress ratio mainly affected the crack propagation behavior in the near-threshold region. Anodic dissolution played an important role in accelerating crack propagation in neutral seawater. However, with the reduction of p H value of artifi cial seawater the hydrogen replacement reaction at crack tip intensifi ed, and the hydrogen damage of material at crack tip greatly promoted the crack propagation.

关 键 词：腐蚀疲劳 裂纹扩展 阳极溶解 氢损伤 

分 类 号：O346.22[理学—固体力学]