稀土铝镁合金纱网耐海水腐蚀性能的研究

STUDY ON SEAWATER CORROSION RESISTING PROPERTIES OF Al-Mg-RARE EARTH ALLOY GAUZE

本文用经典重量法和电化学测量等实验手段,在天然海水及不同浓度的氯化钠溶液等介质中,对不同材料制成的纱网的耐腐蚀性能进行了研究和比较。实验结果表明,Al-Mg-RE合金纱网的耐腐蚀性能随合金中RE含量的增加而明显提高,且总是优于Al-Mg合金、铁丝及塑料等材料织成的纱网。从而,Al-Mg-RE合金是一种可用于海洋生物养殖、工业过滤及沿海建筑等海洋性潮湿环境中使用的优良的纱网材料。

It has been reported that both the manufacturability and corrosion resistance of the recently-invented Al-Mg-RE alloy gauze is superior to those made of Al-Mg alloy bearing no rare earth (RE) elements. In the present paper, the corrosion resistance of gauzes made of various materials, including Al-Mg-RE alloy bearing various RE contents, Al-Mg alloy, low-carbon steel and plastics, has been evaluated and compared.The experimental methods used include immersion method, salt spray test, weight loss test, electrode potential analysis, and metallographic method, etc.The main conclusions drawn from the experimental results are as follows: 1) the corrosion resistance of Al-Mg-RE alloy gauzes in mediums such as running water, natural seawater, NaCl solution with various concentrations, 0.05mol/L Na2SO4 solution, and 10% H2SO4 solution, etc, is superior to those of Al-Mg alloy gauzes made in either China or U. S. A., and much superior to those of gauzes made of low-carbon steel and plastics; 2) the electrode potentials of the Al-Mg-RE alloy in both the natural seawater and 0.05 mol/L Na2SO4 solution increase linearly with increasing RE content in the alloy; 3) in the Al-Mg-RE alloy, the mic-rostructure has been refined and the shape of compounds has been obviously changed compared with those in Al-Mg alloy bearing no RE elements. All these microstructural changes are favourable to the corrosion resistance of the alloy; 4) the Al-Mg-RE alloy gauze may be used as a substitute for those made of Al-Mg alloy, low-carbon steel and plastics in moisture marine or indistrial environment for better serviceability.