脉冲电沉积制备NiW-Si_(3)N_(4)/MWCNTs复合镀层及其性能研究

Study on Preparation of NiW-Si_(3)N_(4)/MWCNTs Composite Coating by Pulse Electrodeposition and Its Performance

长期暴露在复杂工况下的油管、套管钢材表面极易发生腐蚀,导致材料使用寿命降低,影响油井正常生产。通过脉冲电沉积技术在C45钢基材表面制备了NiW-Si_(3)N_(4)/MCNTs复合镀层,并探究了纳米颗粒Si_(3)N_(4)与MWCNTs用量对复合镀层表面微观形貌、硬度和耐蚀性等性能的影响。研究表明:纳米颗粒的加入在抑制Ni-W镀层的(220)与(200)晶面生长的同时,还能促进Ni-W镀层晶粒的细化,大幅度提升NiW-Si_(3)N_(4)/MCNTs复合镀层的显微硬度,最高可达1243.7 HV;与Ni-W镀层相比,NiW-Si_(3)N_(4)/MCNTs复合镀层的阻抗更大,腐蚀速率更低,抗腐蚀性能更好。该项研究为进一步提高Ni-W镀层物理化学性能奠定了理论基础,缓解了油管的腐蚀问题。

It is prone to corrosion for the steel surface of tubing and casing exposed to complex working conditions for a long time,leading to a reduction in the service life of the material and impact on the production of oil wells.NiW-Si_(3)N_(4)/MCNTs composite coating was prepared on the surface of C45 steel substrate by pulse electrodeposition technology,and the influence of the amount of nano-particles Si_(3)N_(4) and MWCNTs used on the surface micromorphology,hardness and corrosion resistance of the composite coating was explored.It was found in the study that nano-particles added could inhibit the growth of the(220)and(200)crystal planes of the Ni-W coating,and promoted the crystal particle refinement of the Ni-W coating,greatly enhancing the microhardness(up to 1243.7 HV)of NiW-Si_(3)N_(4)/MCNTs composite coating;compared with Ni-W coating,NiW-Si_(3)N_(4)/MCNTs composite coating was higher in resistance,lower in corrosion rate and better in corrosion resistance.The study laid a theoretical foundation for further enhancement of physico-chemical properties of Ni-W plating and reduction of tubing corrosion.