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Zn是钢防腐常用的金属。进一步添加其他元素,如Ni,可以降低其腐蚀速率,保持其牺牲性保护作用。采用动电位、恒电位和恒电流技术研究Zn、Ni和不同Ni含量(0.5%~10%)的Zn-Ni合金在3.5%Na Cl溶液中的阳极溶解行为。利用EDX和SEM对Zn,Ni和Zn-Ni合金腐蚀层的成分和显微组织进行表征。恒电位曲线表明,所有研究电极的阳极行为都呈现活化/钝化转变,而且除99.5Zn-0.5Ni合金外,随着Ni含量的增加,合金的钝化趋势减弱。而动电位曲线表明,只有Zn表现出活化/钝化转变。表面分析表明,腐蚀产物主要为氧化物、氯化物和氢氧氯化物。与Zn相比,90Zn-10Ni合金中可观察到细微的裂纹。
Zn is a common metal corrosion of steel. The further addition of other elements, such as Ni, can reduce its corrosion rate and maintain its sacrificial protective effect. The anodic dissolution behavior of Zn, Ni and Zn-Ni alloys with different Ni contents (0.5% ~ 10%) in 3.5% NaCl solution was studied by potentiodynamic, potentiostatic and galvanostatic techniques. The composition and microstructure of the corrosion layer of Zn, Ni and Zn-Ni alloy were characterized by EDX and SEM. The potentiostatic curves show that the anodic behavior of all the investigated electrodes exhibits activation / passivation transition. With the addition of 99.5Zn-0.5Ni alloy, the passivation of the alloy decreases with the increase of Ni content. The kinetic curve shows that only Zn shows an activation / passivation transition. Surface analysis showed that the corrosion products were mainly oxides, chlorides and oxychlorides. Compared with Zn, 90Zn-10Ni alloy can be observed in the fine cracks.