钴含量对Ni-W-Co合金镀层耐蚀性的影响  

Effect of cobalt content on corrosion resistance of electroplated Ni-W-Co alloy coating

作　　者：李治[1] 朱魁[1] 陈天宇 唐波[1] 李勇 LI Zhi;ZHU Kui;CHEN Tianyu;TANG Bo;LI Yong(The Second Gas Production Plant of Petrochina Changqing Oilfield Company,Yulin 719000,China;Puyang City Shunkang Petroleum Engineering Technology Co.,Ltd.,Puyang 457001,China)

机构地区：[1]中国石油长庆油田分公司第二采气厂,陕西榆林719000 [2]濮阳市顺康石油工程技术有限公司,河南濮阳457001

出　　处：《电镀与涂饰》2024年第8期11-17,共7页Electroplating & Finishing

摘　　要：[目的]研究镀层Co含量对Ni-W-Co合金镀层耐蚀性的影响。[方法]通过调节镀液的钴盐(Co SO_(4)·7H_(2)O)用量,在N80钢表面直流电沉积得到不同Co含量的Ni-W-Co合金。通过镀层厚度测量、成分分析、形貌观察、全浸腐蚀试验、动电位极化曲线测试等方式研究了钴盐质量浓度对沉积速率及合金镀层成分、形貌和耐蚀性的影响。[结果]随着镀液中钴盐质量浓度的增大,沉积速率增大,镀层的Co质量分数增大,表面变得粗糙,耐蚀性先变好后变差。Co SO_(4)·7H_(2)O的质量浓度为2.0 g/L时获得的Ni-W-Co合金镀层在5%Na Cl溶液和土酸溶液(由10%盐酸与5%氢氟酸组成)中的腐蚀速率最低,耐蚀性最佳。[结论]通过调整镀液的钴盐用量可电沉积得到适用于油田环境的耐腐蚀Ni-W-Co合金镀层。[Introduction]The effect of cobalt content in Ni-W-Co alloy coating on its corrosion resistance needs to be studied.[Method]Ni-W-Co alloy coatings with different Co contents were electrodeposited on N80 steel at direct current by adjusting the mass concentrations of cobalt sulfate(CoSO_(4)·7H_(2)O)in the electrolyte.The effect of the dosage of cobalt sulfate on the deposition rate,and the composition,morphology,and corrosion resistance of Ni-W-Co alloy coating were studied by coating thickness measurement,composition analysis,morphology observation,immersion corrosion test,and potentiodynamic polarization measurement.[Result]With the increasing of cobalt sulfate concentration in the electrolyte,the deposition rate and the mass fraction of cobalt in Ni-W-Co alloy coating were increased,the coating surface became rough,and its corrosion resistance was initially improved and then deteriorated.The Ni-W-Co alloy coating electrodeposited with 2.0 g/L of CoSO_(4)·7H_(2)O in the electrolyte had the best corrosion resistance,as shown by its lowest corrosion rate in both 5wt%NaCl solution and mud acid solution comprising 10vol%hydrochloric acid and 5vol%hydrofluoric acid.[Conclusion]Corrosion-resistant Ni-W-Co alloy coatings suitable for oilfield environment can be electrodeposited by adjusting the amount of cobalt salt in plating solution.

关 键 词：镍-钨-钴合金 电沉积 油田环境 钴盐 耐蚀性 

分 类 号：TQ153.2[化学工程—电化学工业]