不同厚度镀锡量板材中性盐雾耐蚀性研究

分析不同镀锡量板材间的耐蚀性差距,有助于镀锡工艺的改进并为下游用户的选材提供数据支撑。利用扫描电镜(SEM)、电子探针(EPMA)和光电子能谱仪(XPS)研究了镀锡量为2.8、5.6、8.4和11.2g/m²的等差镀锡量板材经中性盐雾试验后锈点的微观结构、组织特征及元素含量,探究板材间的耐蚀性差距。结果表明,随着镀锡量的增加,镀锡板表面锈点分布由大量弥散状向少量点状转变,锈点形态由树枝状向颗粒状过渡;表征腐蚀程度的O元素富集量显著降低。镀锡量由2.8g/m²增加到5.6g/m²时,镀锡板耐腐蚀性提高明显,5.6g/m²镀锡量板材的性价比优势最为明显。

Study on neutral salt spray corrosion resistance of tinning plates with different tin coating

The analysis of corrosion resistance of tinning plates with different tin coating can improve the tinning process and provide data support of material selection for downstream users. The tinning plates with equal difference of tin coating (2.8, 5.6, 8.4 and 11.2g/m²) were tested by neutral salt spray. Then the microstructure, structure characteristic and elemental content of rust spots was analyzed by scanning electron microscope (SEM), electronic probe microanalyzer (EPMA) and X-ray photoelectron spectrometer (XPS). The difference of corrosion resistance among plates was discussed. The results showed that with the increase of tin coating, the rust spot distribution on surface of tinning plate changed from much scattered-type to little point-type, the morphology transited from dendritic to granular, the enrichment of O element which represented the degree of corrosion decreased significantly. When the tinning coating increased from 2.8 to 5.6g/m², the corrosion resistance of tinning plates was improved greatly. The cost performance superiority of tinning plate with tinning coating of 5.6g/m² was most obvious.