高温预析出对Al-Zn-Mg合金板材应力腐蚀断裂的影响  

Effect of High-Temperature Pre-Precipitation on Stress Corrosion Cracking of Al-Zn-Mg Aluminum Alloy Plate

作　　者：黄兰萍[1] 陈康华[1] 李松[1] 郑强[1] 谢盛辉[2] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083 [2]深圳大学深圳市特种功能材料重点实验室,深圳518060

出　　处：《稀有金属材料与工程》2006年第12期1943-1948,共6页Rare Metal Materials and Engineering

基　　金：教育部新世纪优秀人才支持计划(NCET-04-0752);国家重点基础研究发展规划(2005CB623704);国家自然科学基金(50471057)

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KISCC由7.6MPa.m1/2提高至9.1MPa.m1/2,475℃固溶处理条件下,经过预析出处理后,KISCC由8.9MPa.m1/2提高至11.1MPa.m1/2;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。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.

关 键 词：AL-ZN-MG合金 高温预析出 应力腐蚀断裂 

分 类 号：TG172[金属学及工艺—金属表面处理]