沉积电流密度对不锈钢表面Pd-Co合金镀层耐沸腾含Br^-甲乙混合酸腐蚀性能的影响  

Effect of Electrodeposition Current Density on Microstructure and Corrosion Resistance of Electrodeposited Pd-Co Alloy Coating on 316L Stainless Steel

作　　者：李思锐[1] 左禹[1] 唐聿明[1] 赵旭辉[1] 

机构地区：[1]北京化工大学材料电化学过程与技术北京市重点试验室,北京100029

出　　处：《材料保护》2015年第2期40-43,8,共4页Materials Protection

基　　金：国家科技支撑计划(2012BAE04B01)资助

摘　　要：目前,鲜见Pd-Co合金镀层耐高温非氧化性腐蚀的研究报道。在不锈钢表面电镀了Pd-Co合金层;利用扫描电镜(SEM)、X射线衍射分析(XRD)、硬度测试、腐蚀失重及极化曲线等手段研究了电流密度对Pd-Co合金镀层耐沸腾含0.005 mol/L Br-甲乙混合酸腐蚀性能的影响。结果表明:随着沉积电流密度的增大,Pd-Co合金镀层中Co含量逐渐增多,膜层晶粒大小逐渐降低,硬度先增大后减小;当电流密度较低时,Pd-Co合金镀层具有较低的孔隙率,在沸腾含Br-甲乙混合酸溶液中具有良好的耐蚀性;当电流密度过高时,Pd-Co合金镀层变得疏松,粗糙度增大,孔隙率增多,耐蚀性显著降低;Pd-Co合金层与Pd镀层相比在搅拌条件下的耐腐蚀性能更好。Pd-Co alloy coatings were prepared on 316 L stainless steel by electroplating.The microstructure and phase composition of the as-plated Pd-Co alloy coating were analyzed by scanning electron microscopy and X-ray diffraction,and its hardness was also measured.Furthermore,the effect of electrodeposition current density on the corrosion resistance of Pd-Co alloy coating in the boiling mixed solution of Br- containing formic acid and acetic acid was studied with corrosion mass loss method as well as polarization curve measurement.Results showed that Co content in Pd-Co films increased and the crystalline size decreased when the current density increased,while the hardness of the alloy coating rose initially but declined later therewith.As the current density was low,as-plated Pd-Co alloy coating had a small porosity and exhibited good corrosion resistance in the boiling mixed solution of Br-containing formic acid and acetic acid.As the current density was too high,the Pd-Co alloy coating became coarse and exhibited increased surface roughness and porosity,and its corrosion resistance was significantly reduced.

关 键 词：Pd—Co合金镀层 电沉积 电流密度 微观结构 硬度 耐腐蚀性 沸腾含Br^-甲乙混合酸 

分 类 号：TG174.4[金属学及工艺—金属表面处理]