模拟海洋大气环境下Cl^-质量分数对3003铝合金腐蚀行为的影响

Effect of Chloride Ion Concentration on Corrosion Behavior of 3003 Aluminum Alloy in Simulated Marine Atmospheric Environment

目的研究Cl-质量分数对3003铝合金腐蚀性能的影响,为风电散热器的腐蚀检测和使用寿命评价提供依据。方法采用连续盐雾腐蚀实验模拟海洋大气环境,分析3003铝合金腐蚀产物的微观形貌、元素分布、腐蚀质量损失、点蚀深度,利用极化曲线和阻抗技术分析腐蚀样品的电化学行为。结果当Cl-质量分数低于9%时,样品质量损失随Cl-质量分数的升高而增加,9%时达到最大为7.9937 g/m2;样品腐蚀深度随着Cl-质量分数升高不断加深,9%时达到峰值为44.15μm;腐蚀电流密度随Cl-质量分数的增加而增大,容抗弧半径随Cl-质量分数的增加而减小;Cl-质量分数大于9%时,随着Cl-质量分数增加,腐蚀质量损失和腐蚀深度不断减小,容抗弧半径不断增大,腐蚀电流密度逐渐减小。结论当Cl-质量分数在1%~9%之间时,Cl-质量分数的增加对3003铝合金的腐蚀速率具有明显的加速作用;当Cl-质量分数大于9%时,腐蚀速率呈现逐渐降低的趋势。

ABSTRACT:Objective To study the effect of Cl-concentration on the corrosion behavior of 3003 aluminum alloy, and to provide reference for the corrosion test and service life assessment of the radiator. Methods The accelerated corrosion of 3003 aluminum al-loy in simulated marine atmospheric environment with continuous salt spray corrosion was studied, and the microstructure, element distribution, corrosion mass loss and pitting depth of corrosion products were analyzed. The electrochemical behavior of corrosion samples was studied by polarization curve and impedance technique. Results When the Cl- concentration was lower than 9%, the mass loss of the sample increased with the increase of Cl-concentration and a maximum of 7. 9937 g/m2 was achieved at a Cl-con- <br> centration of 9%;the corrosion depth increased with increasing concentration of Cl-and a peak value of 44. 15 μm was reached at a Cl- concentration of 9%;the corrosion current density increased with the increasing concentration of Cl-, while the capacitive re-actance arc radius decreased with the increase of the concentration of Cl-. When the Cl- concentration was higher than 9%, the corrosion mass loss and corrosion depth continuously decreased with the increasing Cl- concentration, the current density showed a decreasing trend, and the capacitive reactance arc radius showed an increasing trend. Conclusion When Cl- concentration was in the range of 1% ~9%, the increasing Cl-concentration could obviously accelerate the corrosion of 3003 aluminum alloy. When the Cl- concentration was higher than 9%, the corrosion rate decreased with the increasing Cl- concentration.