Al-0.7Mg-0.6Si-xFe合金在富氧环境下的腐蚀行为

The Corrosion Behavior of Al-0.7Mg-0.6Si-xFe alloys in Oxygen-Enriched Environment

摘要: 本文以添加0.1~0.3 wt.% Fe含量的Al-0.7Mg-0.6Si合金为对象，研究了不同Fe含量Al-0.7Mg-0.6Si合金在富氧溶液(57g NaCl + 10ml H₂O₂/L的腐蚀溶液)中的腐蚀行为，通过扫描电镜表征了浸泡腐蚀后样品表面的腐蚀形貌和腐蚀产物，在金相显微镜下表征了晶间腐蚀的截面深度，并与恒应力腐蚀后材料屈服强度的损失情况对比。结果表明，添加不同Fe含量的Al-0.7Mg-0.6Si合金材料的应力腐蚀性能存在差异。在富氧腐蚀环境中，Fe含量0.1 wt.%、0.2 wt.%、0.4 wt.%合金的腐蚀速率分别为：3.11 × 10⁻⁴ mm∙A⁻¹、3.68 × 10⁻⁴ mm∙A⁻¹、4.24 × 10⁻⁴ mm∙A⁻¹；在富氧腐蚀环境中进行应力腐蚀实验，Al-0.7Mg-0.6Si合金强度与断后伸长率的损失随着合金内Fe元素含量的提高而提高，应力腐蚀性能变差。随着微量元素Fe含量的提高，Al-0.7Mg-0.6Si合金内的AlFeSi相数量逐渐增多，并会使得合金材料的应力腐蚀性能变差。

Abstract: In this paper, Al-0.7Mg-0.6Si alloy with 0.1~0.3wt.% Fe was used as the research object. The Al-0.7Mg-0.6Si alloy with different Fe content was studied in oxygen enriched solution (57 g NaCl + 10 ml H₂O₂/L). The corrosion morphology and corrosion products of the sample surface after im-mersion corrosion were characterized by scanning electron microscopy (SEM), and the cross-section depth of intergranular corrosion was characterized by metallographic microscope, and the yield strength loss of materials after constant stress corrosion was compared. The results show that the stress corrosion resistance of Al-0.7Mg-0.6Si alloy with different Fe content is different. The results show that the corrosion rates of 0.1 wt.%, 0.2 wt.%, 0.4 wt.%, are 3.11 × 10⁻⁴ mm∙A⁻¹、3.68 × 10⁻⁴ mm∙A⁻¹、4.24 × 10⁻⁴ mm∙A⁻¹, respectively. The stress corrosion tests in oxygen enriched environment show that the loss of strength and elongation after fracture of Al-0.7Mg-0.6Si alloy increase with the increase of Fe content in the alloy, and the stress corrosion resistance becomes worse. With the increase of trace element Fe content, the amount of AlFeSi phase in Al-0.7Mg-0.6Si alloy increases gradually, and the stress corrosion resistance of the alloy becomes worse.