The Evaluation Of Preparation, Corrosion And Wear Resistance Of The Ni-Sn-P Multicomponent Alloy Coating

The demand for electroless coating in high sulfur environment is gaining momentum.It is found that,benefiting from the thermodynamic stability of Sn element,Sn based coating hold a great potential as alternative for boosting sulfur resistance function.In this present paper,the Ni-Sn-P coating was aimed to prepared on P110 tubing steel by electroless method.Firstly,the optimal plating bath were investigated by orthogonal test.Then,The electrochemical method and high temperature and high pressure corrosion test were used to characterize the evolution of corrosion performance and corrosion mechanism of the optimal plating coating with the change of sulfur content、CO₂,H₂S and salinity.At last,Effects of microstructure and wear resistance properties by different post heat treatment temperature were investigated.The results demonstrate that coating based on the optimal plating bath was determined by holding the promise to compromise between the corrosion prevention and the associated costs in this study with NiCl₂.6H₂O of 30g/L,C₆H₅Na₃O₇.2H₂O agent of 45g/L,NaH₂PO₂.H₂O agent of 24g/L and C₃H₆O₃ agent of 12mL/L,KNaC?H?O?·4H?O,4g/L,Na₂SnO₃ 12.5 g/L which has a uniform and high nucleation rate.Furthermore,the corrosion potential and self-corrosion current density of Ni-Sn-P alloy coating change in the form of a parabola with the S^2-content increases,while the corrosion in different simulated high temperature and high pressure environment of oil field is extremely slight by forming thermodynamic stability and protective Ni（OH）₂/NiO and SnO₂ film.However,the Electrochemical impedance spectroscopy of Ni-Sn-P coating indicated after immersed in different S^2-contents,the corrosion products Ni₃S₂ in Ni-Sn-P coating can induced porosity and thus caused decreased corrosion performance.In addition,the structure of the coating gradually crystallized when the heat treatment temperature increased,and the Ni₃P hard phase precipitated at 450℃by post heat treatment.The result revealed that the wear resistance of Ni-Sn-P coating increase by crystallized degree,while hardness is the opposite.