Corrosion Resistance and Protection Mechanism of Hot-dip Zn-Al-Mg Alloy Coated Steel Sheetunder Accelerated Corrosion Environment
Corrosion Resistance and Protection Mechanism of Hot-dip Zn-Al-Mg Alloy Coated Steel Sheetunder Accelerated Corrosion Environment
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加速腐蚀环境下热浸锌铝镁合金镀层钢板的耐蚀性及防护机制
DOI：
10.2355/tetsutohagane1955.86.8_534
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发表时间：
2000
影响因子：
0.3
通讯作者：
Toshiharu Kittaka
中科院分区：
文献类型：
--
作者：
A. Komatsu;H. Izutani;Takao Tsujimura;Atsushi Andoh;Toshiharu Kittaka
研究了热浸镀Zn-6%Al-0·3%Mg合金镀层钢板在循环腐蚀试验中的腐蚀行为。随着涂层中Mg含量的增加，涂层的耐腐蚀性提高，并且在3%Mg时观察到最高的耐腐蚀性。与Zn-0.2%Al和Zn-4.5%Al-0.1%Mg合金镀层钢板相比，Zn-6%Al-3%Mg合金镀层钢板中氢氧化碳酸锌和氧化锌的形成受到更长时间的抑制。结果表明，氯化锌氢氧化物稳定地存在于涂层表面。从CCT后在5%NaCl水溶液中的极化行为来看，Zn-6%Al-3%Mg合金镀层的腐蚀电流密度远小于Zn-0.2%Al和Zn-4.5%Al-0.1%Mg合金镀层的腐蚀电流密度。由于碳酸锌氢氧化物和氧化锌对涂层的粘附性差，并且具有多孔结构，因此认为这些腐蚀产物对涂层几乎没有保护作用。因此，可以得出结论，Mg抑制了这种非保护性腐蚀产物的形成，从而显著提高了耐腐蚀性。
Synopsis : Corrosion behavior of hot-dip Zn-6%Al-0•`3%Mg alloy coated steel sheets in cyclic corrosion test (CCT) has been investigated. The corrosion resistance was improved with increasing Mg content in the coating layer, and the highest corrosion resistance was observed at 3% Mg. In Zn-6%Al-3%Mg alloy coated steel sheet, the formations of zinc carbonate hydroxide and zinc oxide were suppressed for longer duration compared with Zn-0.2%Al and Zn-4.5%Al-0.1%Mg alloy coated steel sheets. As a result, zinc chloride hydroxide existed stable on the surface of the coating layer. From the polarization behaviors in 5% NaCl aqueous solution after CCT, it was found that the corrosion current density of Zn-6%Al-3%Mg alloy coated steel sheet was much smaller than those of Zn-0.2%Al and Zn-4.5%Al-0.1%Mg alloy coated steel sheets. As zinc carbonate hydroxide and zinc oxide had poor adhesion to the coating layer and had porous structures, these corrosion products were considered to have little protective action for the coating layer. Therefore, it was concluded that Mg suppressed the formation of such nonprotective corrosion products, resulting in the remarkable improvement of corrosion resistance.