论文部分内容阅读
采用失重、动电位极化和裂纹扩展速率测试方法,对不同时效态7050铝合金板材的腐蚀速率进行测定,并利用金相显微镜对浸蚀表面和纵截面的腐蚀形貌进行观察。结果表明:随着时效程度的增加,合金腐蚀类型由局部腐蚀逐渐向均匀腐蚀转变,腐蚀速率逐渐增加;而腐蚀裂纹扩展方式由沿晶腐蚀逐渐向穿晶腐蚀转变,导致腐蚀裂纹扩展速率不断减小;峰值时效态合金的腐蚀电流密度最大,欠时效态的次之,过时效态的最小。
The corrosion rate of 7050 aluminum alloy sheet with different aging conditions was measured by weight loss, potentiodynamic polarization and crack propagation rate test method. The corrosion morphology of the erosion surface and longitudinal section was observed by optical microscope. The results show that the corrosion type gradually changes from localized corrosion to uniform corrosion and the corrosion rate gradually increases with the increase of aging degree. However, the corrosion crack growth mode gradually changes from intergranular corrosion to transgranular corrosion, which leads to the decreasing of corrosion crack growth rate The corrosion current density of the peak-aged alloy is the largest, the second one owes the second one, and the second one is the least.