Investigation Of Zinc And Manganese Phosphation Effect On The Fatigue Life Of Rolling Elements

As the most commonly used core parts in the rotating machinery,the technical level and quality of the rolling bearing have a great impact on the performance and service life of the main working machine.With the rapid development of the industrial technology,the performance requirements of the rolling bearings are getting higher and higher.According to the data,30% of the faults in the rotating machinery are caused by bearings.For some large low speed heavy load bearings,such as rolling mills,wind power large bearings,It is very easy for moisture to enter the lubricating oil,and due to fluctuations in load,speed and changes in lubricant performance,scratches are particularly prone to occur,at this time,the fatigue life of the bearing will be significantly reduced.At present,the surface phosphating treatment is used to prevent the smearing of the bearing,but there are few studies on the influence of phosphating treatment on the fatigue life of bearings.Some studies have proposed that the manganese phosphating or zinc phosphating on the surface of steel and iron can effectively reduce the friction coefficient of the friction pair surface,prevent the bite or scratch in the wear process,reduce the movement resistance and noise.This project is supported by the project fund of SKF Netherlands R & D Center.The fatigue life of the phosphating rollers is tested on roller-on-ball rolling contact fatigue(RCF)testing machine.The influence mechanism of manganese phosphating and zinc phosphating on the contact fatigue life of rollers is analyzed and compared.The effect of manganese phosphating on the fatigue life of rollers under the condition of water contamination lubrication is investigated.This paper mainly completes the following work:1)The research results and theories regarding bearing smearing,rolling contact fatigue life,application of phosphating treatment in bearing production,and the influence of water on contact fatigue life are reviewed and summarized,and make a preliminary summary of the existing research results.2)The classification of phosphating,the properties of phosphating film and the mechanism of phosphating reaction are introduced,and the influencing factors of phosphating film were analyzed.Based on the research purpose of this topic,manganese phosphating and zinc phosphating are selected as the surface treatment methods of the rollers in this paper,and the phosphating film is briefly evaluated and analyzed.3)The self-developed roller-on-ball rolling contact fatigue(RCF)testing machine is introduced,the lubrication system is optimized and the measurement and control system of the testing machine is improved.During the test process,real-time data collection,record and preservation,as well as the extent of damage to the roller display are realized.At the same time,the stopping mechanism is optimized to eliminate the interference of abnormal conditions and realize the intelligent stopping function.4)The fatigue life test of the phosphating rollers under the condition of pure oil lubrication is completed on roller-on-ball contact fatigue testing machine.And the fatigue life test of manganese phosphating roller under the condition of water contamination lubrication.The optical microscope and scanning electron microscope(SEM)are used to analyze the surface of the rollers,the surface components of the rollers wear scar are analyzed by Energy Disperse Spectroscopy(EDS).The influence mechanism of manganese phosphating and zinc phosphating on the fatigue life of rollers are analyzed.5)The existing research works and conclusion are summarized,and the further research in the future is prospected.