| 引用本文: | 曹礼敏,黎德育,李宁.间歇电沉积粒状铬镀层的过程及其性能[J].哈尔滨工业大学学报,2018,50(8):174.DOI:10.11918/j.issn.0367-6234.201703075 |
| CAO Limin,LI Deyu,LI Ning.Research on the process and performance of the chromium coatings prepared by intermittent electrodeposit[J].Journal of Harbin Institute of Technology,2018,50(8):174.DOI:10.11918/j.issn.0367-6234.201703075 |
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| 摘要: |
| 为改善镀铬板的可焊性，用间歇电沉积法在钢板表面获得了呈粒状分布的铬镀层.采用扫描电子显微镜、能谱仪和X射线衍射研究了电流中断时间对粒状铬形貌和结晶取向的影响；然后利用库伦电解法测量了镀层的铬含量；最后通过测量接触电阻和观察焊接面评价了其可焊性.实验结果表明：粒状铬镀层呈现为分散粒状铬均匀分布在连续层状铬上，随电流中断时间的延长，粒状铬密度逐渐增加，焊接电阻逐渐变小.相比于连续电沉积，间歇电沉积所得铬镀层出现了铬(211)晶面的择优取向.相同电荷量下，间歇电沉积所得铬镀层的镀铬量比连续电沉积的要高.电流中断时，生成不连续的氧化膜使得层状铬局部钝化，而活性点优先放电形成分散的粒状铬.同一压力下，间歇电沉积所得镀铬板的接触电阻远小于连续电沉积的; 一定焊接电流下，前者可以焊接，而后者不能.电流中断期间，局部钝化的出现有助于粒状铬的生成，使得镀铬板的可焊性提高.
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| 关键词: 间歇电沉积 粒状铬 电流中断时间 局部钝化 可焊性 |
| DOI：10.11918/j.issn.0367-6234.201703075 |
| 分类号:TQ153.1 |
| 文献标识码:A |
| 基金项目: |
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| Research on the process and performance of the chromium coatings prepared by intermittent electrodeposit |
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CAO Limin,LI Deyu,LI Ning
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（School of Chemistry ang Chemical Engineering,Harbin Institute of Technology, Harbin 150001, China）
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| Abstract: |
| To improve the weldability of the Tin Free Steel, the granular chromium coatings were obtained on the steel by intermittent electrodeposit. The morphology and structure of the granular chromium were investigated and analyzed with scanning electron microscopy (SEM), X-ray diffraction (XRD), and the chromium content of the coatings were measured by the coulomb electrolysis method. The weldability of TFS was evaluated by measuring the contact resistance and observing the welding surface. Experimental results showed that the granular chromium distribute on the platelike chromium evenly. As the current interruption time extends, the density of the granular chromium gradually increases, while the welding resistance decreases. Compared with continuous electrodeposit, the preferred orientation of Cr (211) plane appears on the granular chromium prepared by intermittent electrodeposit. The chromium content of coating prepared by intermittent electroplating was higher than that of the continuous plating under the same charge amount. When the current is interrupted, the discontinuous oxide film is formed to make the layered chromium partially passivated, and the active point preferentially discharges to form dispersed granular chromium. When the pressure keeps constant, the contact resistance of the granular chromium coating is much smaller than that of the conventional chromium coating, and under same welding current, the former can be welded while the latter can't. During the current interruption, the presence of partial passivation contributes to the formation of granular chromium, which improves the weldability of TFS.
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| Key words: intermittent electrodeposit granular chromium current break partial passivation weldability |
