轧制变形对7A55铝合金晶间腐蚀的淬火敏感性的影响

研究了轧制变形量对7A55铝合金晶间腐蚀的淬火敏感性的影响。结合金相组织和透射电镜组织观察, 对影响机理进行了分析和讨论。实验结果表明, 淬火速率的下降会导致合金的抗晶间腐蚀能力降低; 随着轧制变形量的增大, 合金晶间腐蚀的淬火敏感性增大。组织观察表明, 缓冷条件下, 平衡相的析出、晶界无沉淀析出带的宽化, 造成了晶间腐蚀的淬火敏感性。变形量的增加, 合金再结晶程度提高, 晶粒组织更加扁平、细小导致了合金晶间腐蚀的淬火敏感性的提高。

Effect of Rolling Deformation on Quench Sensitivity Relative to Intergranular Corrosion of 7A55 Aluminun Alloy

The effect of rolling deformation on quench sensitivity relative to intergranular corrosion of 7A55 aluminum alloy was investigated. The mechanisms were analyzed and discussed by metallographic observation and transmission microscope observation of the microstructure. The results showed that the decrease of quench rate reduced the resistance to intergranular corrosion. The quench sensitivity relative to intergranular corrosion increased with the increase of rolling deformation. The microstructure observations indicated that the slow quench-induced precipitates and the widening of the precipitate-free zone on grain boundary caused the quench sensitivity relative to intergranular corrosion. Furthermore, the increased deformation, elongated and refined grains and increased recrystallization were responsible for the enhancement of the quench sensitivity relative to intergranular corrosion.