Study On Surface Modification Of Electroless Nickel Planting On Inner Wall Of Mud Pump Cylinder Liner

As the key equipment in oil and gas engineering,the mud pump is in a core position in drilling fluid circulation system.In the process of mud pump operation,a key component of the mud circulation is the friction pair of the piston cylinder.Because of the complex composition of the circulating liquid,the working condition of the piston liner is bad and the wear is serious.In order to meet the actual requirements of the drilling production,modern power and emissions are increasing,pressure and pressure also increases,so it is becoming more and more serious under the high speed mechanical wear and PH corrosion,the research on how to improve the performance to resist high load-carrying capacity,wear,corrosion,alkali that is important.The surface coating material is commonly used in surface modification technology,due to electroless plating process with no external power supply,the advantages of the coating distribution obtained uniform and dense microstructure of good and beauty,it has gradually become an important surface treatment technology.The electroless nickel plating coating has good adhesion,good corrosion resistance,high adhesion and wear resistance,which greatly improve the service life of the piston liner of mud pump.This paper discussed the technical characteristics of electroless nickel plating,The preparation technology of matrix material is studied.The composition and function of the bath were analyzed,and the 42 CrMo coating samples with different thickness and different heat treatment conditions were obtained.The coating sample were obtained from experiment,Determination of corrosion resistance of coating samples by weight loss method and electrochemical method.The research pointed out that the nickel coating can improve the surface corrosion resistance,it plays an important role in corrosion resistance to improve the workpiece;coating thickness has an important influence on the corrosion resistance of the plating,weight loss method research pointed out that thick coatings can not improving corrosion resistance,but performance may deteriorate parts;heat treatment coating directiy impact the organizational structure of nickel pHospHorus coating structure,unreasonable heat treatment temperature and holding time will deteriorate and organization of crystal defects,thereby reducing the corrosion resistance.Finally,the fatigue experiment of chemical nickel plating of the samples points out that the research on fatigue performance of coating that is treated,after 42 CrMo materials by chemical plating,fatigue strength greatly reduced the sample,sample after heat treatment and the fatigue strength is lower.Therefore,the use of electroless nickel plating process to deal with the inner wall of the cylinder liner of mud pump can improve the corrosion fatigue performance of the cylinder liner and prolong the servicelife of the liner.