【摘要】 采用电化学测试、浸泡实验、金相显微镜、扫描电镜、透射电镜等实验手段研究固溶处理对7A55铝合金局部腐蚀性能的影响。结果表明:轧板中大量的第二相使轧板发生严重的腐蚀,整个表面被剥落下来。单级固溶的再结晶程度较低,亚晶组织细小,但合金残留第二相较多,耐蚀性能差。低温回复+高温固溶处理(450℃/1h+480℃/30min)可以将粗大第二相大部分溶解,且获得最少的再结晶分数和细小亚晶组织。实验结果表明,450℃/1h+480℃/30min固溶处理具有最佳的耐局部腐蚀性能。更多还原

【Abstract】 The influence of solution heat treatment on the localized corrosion of the 7A55aluminum alloy were investigated by means of electrochemical test,immersion tests,optical microscopy,scanning electron microscopy(SEM),transmission electron microscopy(TEM).The results show that a large number of coarse constituent particles cause severe corrosion of the rolled plate and the entire surface is exfoliated.Single-stage solution treatment causes lower recrystallization fraction and small size of sub-grains,but the large number of remnant coarse particles results bad performance of corrosion resistance.The 450℃/1h+480℃/30min solution heat treatment results in improved dissolution of coarse second phase particles,low recrystallization percentage and small size of sub-grains.The results indicate that the 7A55aluminum alloy has the best localized corrosion resistance under the condition of the 450℃/1h+480℃/30min solution heat treatment.更多还原