中文摘要：

研究了高温预析出对7A52合金组织、时效硬化和应力腐蚀断裂的影响。结果表明：高温预析出处理在保持7A52合金强度、塑性的同时，可提高合金抗应力腐蚀性能。480℃固溶处理条件下，经过预析出处理后，合金应力腐蚀开裂界限应力强度因子局KISCC由7．6MPa．m^1/2。提高至9．1MPa．m^1/2，475℃固溶处理条件下，经过预析出处理后，KISCC由8．9MPa．m^1/2。提高至11．1MPa．m^1/2;未经预析出处理的7A52合金应力腐蚀断裂区发生严重的阳极溶解腐蚀，晶界和亚晶界均发生断裂，经高温预析出处理后，应力腐蚀裂纹仅沿平行晶界扩展；高温预析出处理使晶界析出相粗化显著、离散度增大且晶界析出相Cu含量提高，这是合金抗应力腐蚀性能得到显著改善的重要原因。

英文摘要：

The effect of high-temperature pre-precipitation on the microstructure, age hardening and stress corrosion cracking of 7A52 alloy has been investigated. The optical and transmission electron microscopy and energy spectrum analysises show that the high-temperature pre-precipitation could enhance the discontinuity of grain boundary precipitates and make Cu content of grain boundary precipitates increasing. The stress corrosion cracking resistance could be improved with non-deteriorated strength and plasticity via the high-temperature pre-precipitation, After pre-precipitating stress intensity factor KISCC of 7A52 alloys solution treated at 480℃ raised from 7-6MPa.m^1/2 to 9.1MPa.m^1/2, And after pre-precipitating stress intensity factor KISCC of 7A52 alloys solution treated at 475℃raised from 8.9 MPa.m^1/2 to 11.1 MPa.