碳钢表面Co电镀层制备模拟样及扩散行为研究

Preparation of Co Coating on Carbon Steel Surface Using Electroplating Process and Research on Its Element Diffusion Behavior

为了加快核素污染金属表面速度,更快地制造模拟样品,采用电镀工艺在碳钢试片表面制备Co层。镀液配方:硫酸钴20 g/L、硼酸15 g/L、蒸馏水1 L、氯化钠10 g/L、络合剂环己酮肟(CHO)1 g/L;电镀工艺参数:镀液PH值为4.5、电流密度为1 A/dm^(2)、温度为50℃、电镀时间为2 h。对电镀完成的样品高温处理,加快Co在碳钢表面上的扩散,极大减少了模拟样的制作周期和制作成本。在电镀过程中通过正交试验获得电镀钴层的最佳电镀工艺。SEM测试表明优化工艺前后形貌变化明显,优化后镀层相对更加均匀、平整。EDS测试表明碳钢表面成功镀上钴金属层且镀层分布致密。通过GD-OES对元素深度剖析,对钴元素在样品内侧扩散行为进行研究,结果表明镀层与基材主元素之间发生相互渗透扩散,Co在铁相中是沿着晶界扩散且在铁相中分布是连续的。

In order to speed up the rate of nuclide contamination of metal surface and make simulated samples faster,the silver-white Co layer was prepared on the surface of carbon steel by electroplating process.The electroplating process was:cobalt sulfate 20 g/L,boric acid 15 g/L distilled water 1 L,Sodium chloride 10 g/L,Cyclohexanone oxime(CHO)1000 ppm,current density of 1 A/dm^(2),temperature was 50℃,PH value was 4.5,electrodeposition time was 2 h.The high temperature treatment of electroplated samples accelerated the diffusion of Co on the surface of carbon steel and greatly reduced the production cycle and production cost of simulated samples.The best electroplating technology of cobalt layer was obtained by orthogonal test during electroplating.SEM test showed that the morphology changes obviously before and after the optimization process,and the optimized coating was more uniform and smooth.EDS test showed that cobalt was successfully coated on the surface of carbon steel and the coating distribution was dense.GD-OES analyzed the element depth and studied the diffusion behavior of cobalt in the inner side of the sample.The results showed that the main elements of the coating and the substrate had mutual diffusion,and that the cobalt diffused along the grain boundary in the iron phase and distributed continuously in the iron phase.