高温预析出和固溶温度对7A52合金应力腐蚀开裂的影响

Effect of High Temperature Pre-precipitation and Solution Temperature on SCC of 7A52 Alloy

通过对高温预析出处理的7A52合金在T61和自然时效状态的强度、硬度、电阻率和应力腐蚀开裂(SCC)的测试,对比分析了高温预析出对7A52合金自然时效和T61时效状态下应力腐蚀性能的影响。研究结果表明:高温预析出可以提高自然时效和人工时效状态7A52合金的抗应力腐蚀性能,同时强度和伸长率有所增加;对于T61时效状态的7A52合金可保持其拉伸强度在500MPa,伸长率在13.0%。475℃固溶处理后T61状态下的7A52合金,不论是否经高温预析出处理合金抗应力腐蚀性能都优于经480℃固溶处理的T61状态下的7A52合金的抗应力腐蚀性能。

The properties,such as tensile property at room temperature, hardness, electrical resistivity and SCC of 7A52 alloy by high temperature pre-precipitation treatment were tested. The effect of high temperature pre-precipitation on the SCC of 7A52 alloy at T61 treatment and natural ageing was analyzed and compared. The results show that high temperature pre-precipitation can enhance the resistance to SCC of 7A52 alloy and increase the strength and elongation at subsequent natural ageing and artificial ageing. To the aged aluminum alloys at T61 treatment, high temperature pre-precipitation can keep the strength at 500MPa and elongation at 13.0%. At T61 ageing,the SCC of 7A52 alloys which were solutioned at 475℃ is superior to that of 7A52 alloys which were solutioned at 480℃ ,whether they were treated by high temperature pre-precipitation or not.