回归再时效对7×××系铝合金强度及耐腐蚀性能的影响

Effect of RRA on Strength and Corrosion Resistance of 7 × × × Aluminum Alloy

采用室温拉伸实验、电导率与极化曲线测试等分析方法,研究RRA工艺中回归温度与回归时间对高强铝合金强度和耐腐蚀性能的影响规律。结果表明,与T6态合金相比,适当的RRA工艺既使合金的强度得到提高,又可大幅度提升耐腐蚀性能。随着回归温度与回归时间的增加,合金强度先增大后减小,在190℃×20min回归时达到峰值702.2MPa,而耐腐蚀性能则持续增加。回归温度在210℃以上时虽然耐腐蚀性增加明显,但是却损失了部分强度。

The influence of regression temperature and regression time on the strength and corrosion resistance of high strength alumi⁃num alloy in RRA process was studied using tensile test at room temperature,electrical conductivity and polarization curve test.The results show that,compared with T6 alloy,proper RRA not only improves the strength of the alloy,but also greatly improves the cor⁃rosion resistance.The strength of the alloy increased and then decreased with the increase of regression temperature and regression time,reached the peak value of 702.2MPa at 190℃ 20min regression,while the corrosion resistance continued to increase.When the temperature was above 210℃,the strength decreased though the corrosion resistance increased obviously.