采用慢应变速率拉伸 (SSRT)技术测试了LC4铝合金在空气和质量分数为 3.5 %的NaCl溶液中的应力腐蚀断裂 (SCC)行为 .研究了应变速率对铝合金SCC行为的影响和氢在LC4高强铝合金应力腐蚀断裂过程中的作用 .试验结果表明 ,LC4合金具有SCC敏感性 ,在潮湿空气中发生应力腐蚀断裂 ,而在干燥空气中不发生应力腐蚀断裂 .对于长横取向的LC4铝合金试样 ,在应变速率为 1.331× 10 6s 1时 ,其SCC敏感性比应变速率为 6 .6 5 5× 10 6s 1时的敏感性大 .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 . The stress corrosion cracking (SCC) behavior of LC4 aluminum alloy in air and 3.5% NaCl solution was tested by slow strain rate tensile (SSRT) technique.The effect of strain rate on the SCC behavior of aluminum alloy and the effect of hydrogen on LC4 high-strength aluminum alloy during stress corrosion cracking.The experimental results show that LC4 alloy has SCC sensitivity, stress corrosion cracking occurs in humid air and no stress corrosion cracking occurs in dry air.For LC4 aluminum with long transverse orientation When the strain rate is 1.331 × 10 6s 1, the sensitivity of the alloy to SCC is greater than that of the strain rate of 6.65 × 10 6s 1. Under humid air and anodic polarization, the aluminum alloy The mechanism of stress corrosion cracking is dominated by anodic dissolution, with almost no effect of hydrogen. Hydrogen embrittlement plays a major role in pre-hydrogenation or cathodic polarization, and the pre-hydrogenation time can accelerate the stress corrosion cracking of LC4 alloy.