Finite Element Analysis Of Residual Stress Of Wear Resistant Iron-based Coatings By Plasma Spraying

With the rapid development of China industry,the requirements of various machinery on the performance of parts are getting higher and higher.Plasma spraying is a surface strengthening technology,which has the advantages of wide range of process parameters and good bonding strength.Fe Si B coating has high hardness,wear resistance,corrosion resistance and high temperature resistance.The size and distribution of residual stress have a great influence on the bonding strength,thermal cycle fatigue life and thermal shock resistance of Fe Si B coating.Therefore,it is of great significance to study the influencing factors of residual stress of Fe Si B coating.Because the plasma spraying process cannot be monitored in real time,numerical simulation is used to study the change rule of stress in the coating preparation process.In this paper,the process of preparing Fe Si B coating and Al₂O₃/Fe Si B composite coating on304L substrate by plasma spraying was simulated by finite element method.The effects of plasma spraying power,scanning speed and coating thickness on the temperature field and stress field of Fe Si B coating and Al₂O₃/Fe Si B composite coating were analyzed.Through the research and analysis of the temperature field,the temperature distribution between the coating and the substrate is not uniform.By comparing the temperature field of the Al₂O₃/Fe Si B composite coating with the Fe Si B coating,it can be seen that the highest temperature of the temperature field of the Al₂O₃/Fe Si B composite coating is higher than the highest temperature of the Fe Si B coating,and along the thickness direction,the temperature of the Al₂O₃/Fe Si B composite coating changes more dramatically.Through the research and analysis of the stress field,stress concentration occurs at the edge of the coating and the interface between the coating and the substrate.The coating stress is proportional to the spraying power and inversely proportional to the scanning speed.By comparing the stress field of Al₂O₃/Fe Si B composite coating and Fe Si B coating,it can be seen that under the same process parameters,the maximum residual tensile stress in the X-axis direction of Al₂O₃/Fe Si B composite coating is less than the Fe Si B coating.Adding Al₂O₃to Fe Si B will reduce the maximum residual tensile stress of coating and substrate and improve the service life of coating.