不同港口海域铝合金腐蚀行为研究

目的获得1060铝合金和5083铝合金在不同港口海域的腐蚀规律。方法采用实海试验方法获得材料表面的腐蚀形貌及腐蚀速率,并利用腐蚀图像处理技术分析海生物覆盖状态。结果不同海域铝合金试样表面附着海生物种类不同,青岛海域试样表面主要附着牡蛎,舟山海域试样主要附着藤壶和海藻,三亚海域主要附着藤壶和牡蛎。1060铝合金和5083铝合金在不同海域海水中以点蚀和缝隙腐蚀为主,海生物附着对铝合金腐蚀有明显影响,较严重的腐蚀点出现在牡蛎或藤壶下面及边缘。三海域中两种铝合金在舟山海域的腐蚀速率最大,三亚海域次之,青岛海域最小。不同海域铝合金试样表面海生物覆盖面积不同,三亚海域试样表面海生物覆盖面积百分比最大,青岛海域次之,舟山海域最小。结论由于海水环境不同,青岛、舟山及三亚海域铝合金试样表面海生物种类以及海生物覆盖面积明显不同,海生物的附着在一定程度上减缓了铝合金的腐蚀,另外也使得铝合金更易产生缝隙腐蚀和点蚀。

Corrosion Behaviors of Aluminum Alloys in Different Harbors

Objective To obtain corrosion regularity of 1060 aluminum alloy and 5083 aluminum alloy in different harbors. Methods The real-sea test was carried out to obtain the corrosion morphology and corrosion rate of the material surface, and corrosion image processing techniques were used to analyze the marine organisms cover status. Results There are different kinds of marine organisms attached to the surface of aluminum alloy specimens in different harbors. The surfaces of the specimens at Qingdao harbor were mainly attached by oysters. The surfaces of the specimens at Zhoushan harbor were mainly attached by barnacles and seaweeds. The surfaces of the specimens at Sanya harbor were mainly attached by barnacles and oysters. The corrosion form of 1060 aluminum alloy and 5083 aluminum alloy were mainly pitting corrosion and crevice corrosion in different harbors. The adhesion of marine organisms had significant impacts on corrosion of aluminum alloys. The serious corrosion areas appeared under the oysters or barnacles, or near the edges of the sea creatures and material matrix. The sequence of the corrosion rates of the two aluminum alloys in the three harbors from the largest to the lowest was: Zhoushan Harbor, Sanya Harbor, and Qingdao Harbor. The sea creature coverage area of aluminum alloy specimens in different harbors was different. The sequence of the sea creature cover area of the two aluminum alloys in the three harbors from the largest to the lowest was: Sanya Harbor, Qingdao Harbor, and Zhoushan Harbor. Conclusion The species of marine organisms and the sea creature coverage area on the surface of aluminum alloy specimens of these three harbors are significantly different due to different seawater environments. To a certain extent, the adhesion of sea creatures slows down the corrosion of aluminum alloys. However, it also makes the aluminum alloys easier to produce crevice corrosion and pitting corrosion.