氢对LC4高强铝合金应力腐蚀断裂的影响

采用慢应变速率拉伸试验研究了氢在LC4高强铝合金应力腐蚀断裂过程中的作用。结果表明，LC4合金在干燥空气中不发生应力腐蚀断裂，而在潮温空气中发生应力腐蚀断裂，在潮湿空气和阳极极化条件下，铝合金的应力腐蚀断裂机理是以阳极溶解为主，氢几乎不起作用，在预渗氢或阴极极化条件下，氢脆起主要作用，预渗氢时间延长可加速LC4合金的应力腐蚀断裂。

EFFECT OF HYDROGEN ON STRESS CORROSION CRACKING OF LC4 ALUMINUM ALLOY

The effect of hydrogen on stress corrosion cracking (SCC) of the high-strength LC4 aluminum alloy in 3.5%NaCl solution has been studied using slow strain rate tension technique.The experimental results showed that the alloy is susceptible to SCC in humid air,especially in NaCl solution.SCC may occur in the mechanisms of anodic dissolution and hydrogen embrittlement,but the mechanisms would be varied under various conditions.In humid air,or under the condition of anodic polarization in 3.5% NaCl solution,the mechanism of SCC is mainly anodic dissolution.Under the condition of hydrogen pre-permeation or cathodic polarization,hydrogen embrittlement plays a key role during the SCC process.The results also indicated that the SCC resistance of LC4 alloy decreases with increasing the time of hydrogen pre-permeation.