5B70铝合金板材腐蚀性能的研究

Research on the corrosion performance of 5B70 aluminum alloy sheets

采用剥落腐蚀试验、晶间腐蚀试验、阳极极化曲线测试等试验方法,研究了冷轧5B70铝合金经200℃、250℃、300℃、350℃、400℃和450℃退火1 h后剥落腐蚀和晶间腐蚀性能的变化。结果表明,5B70铝合金经200℃1 h退火处理后耐剥蚀和晶间腐蚀性能最差,250℃1 h退火后耐剥蚀和晶间腐蚀性能最好。合金经250℃以上退火处理后耐腐蚀性能较好,基本未发生明显的剥蚀和晶间腐蚀现象。保证5B70铝合金最佳耐蚀性的退火温度为250℃,保温时间为1 h。

Variation of the exfoliation corrosion properties and intergranular corrosion properties of cold-rolled 5B70 aluminum alloy after annealed at 200℃, 250℃, 300℃, 350℃, 400% and 450% for lh were studied by the exfoliation corrosion test, the intergranular corrosion test, and the potential dynamic polarization. The results show that the worst exfoliation corrosion and intergranular corrosion resistance of 5B70 aluminum alloy are obtained when they are annealed at 200℃ for 1 h. The best exfoliation corrosion and intergranular corrosion resistance of 5B70 aluminum alloy are obtained when they are annealed at 250℃ for 1 h. In general, no obvious corrosion behaviors happen when the annealing temperature is above 250℃. The most suitable annealing process is 250℃ 1 h to obtain the best corrosion resist- ance of 5B70 aluminum alloy.