(1．北京工业大学 材料科学与工程学院，北京 100124；
2．东风商用车技术中心 工艺研究所，武汉 430056)
摘 要: 采用晶间腐蚀性能测试及透射电镜研究冷变形及退火对5E06铝板晶间腐蚀性能的影响规律。结果发现：5E06铝板的晶间腐蚀性能与β相的分布、形貌和析出量密切相关。当冷变形量低于40%时，β相较易在晶界析出达到连续而使合金晶间腐蚀性能恶化；当变形量增加到55%以上时，经稳定化退火后β相在晶界不容易连续，5E06铝板晶间腐蚀性能良好。进一步的敏化试验表明，经55%~80%冷变形的5E06铝板在120 ℃稳定化退火的效果并不理想，而220℃的稳定化退火由于获得了比较均匀的亚晶组织且β相在晶界/亚晶界断续分布并一定程度上降低基体中镁原子的过饱和度，可使稳定化退火态5E06铝板在长期使用过程中晶间腐蚀性能不发生明显退化。
关键字: 冷变形；稳定化退火；5E06铝合金；晶间腐蚀；敏化；β相
（1. School of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China；
2. Materials and Technology Research Institute, Dongfeng Commercial Vehicle Technical Center, Wuhan 430056, China）
Abstract:The effects of cold deformation and annealing on the intergranular corrosion property of 5E06 aluminium alloy plates were investigated by intergranular corrosion property tests and transmission electron microscope (TEM). The results show that the intergranular corrosion property of 5E06 aluminium alloy plates has close relationship with the distribution, morphology and quantity of β phase. When the cold deformation is under 40%, β phase is easy to precipitate continuously at grain boundaries which will worsen the intergranular corrosion property. When the cold deformation exceeds 55%, β phase is not easy to achieve succession after stabilizing annealing and the 5E06 aluminum alloy plates have favorable intergranular corrosion property. Sensitization tests indicate that the effect of stabilizing at 120 ℃ is not desirable for 5E06 aluminum alloy plates at cold deformation of 55%-80%, whereas the aluminum alloy plates annealed at 220 ℃ can obtain homogeneous subgrains and β phase distributes discretely at grain boundaries and subgrain boundaries which can reduce the degree of supersaturation to some extent. Therefore, the intergranular corrosion property of 5E06 aluminum alloy plates at stabilizing annealing states won’t degenerate obviously in the long-term using process.
Key words: cold deformation; stabilizing annealing; 5E06 aluminium alloy; intergranular corrosion; sensitization; β phase
