Research On Grinding Force And Surface Integrity Of 18CrNiMo7-6 Steel In Cylindrical Grinding

The development of the national manufacturing industry is inseparable from the breakthrough of manufacturing technology.In recent years,the anti-fatigue manufacturing technology with the construction of the surface metamorphic layer as the core is developing rapidly.Cylindrical grinding,as an economical and reliable processing method,is widely used in the machining of difficult-to-cut materials,and it is the content that must be studied to develop anti-fatigue manufacturing technology.Residual stress and roughness are important evaluation indicators of surface integrity,which have a great impact on fatigue life,grinding force is an important output parameter in the machining process,which can reflect the material's grinding performance.It is the main cause of grinding heat and grinding vibration during the grinding process.It will affect the grinding quality.Therefore,exploring the influence of grinding parameters on grinding force,residual stress and roughness is of great significance for achieving the balance of machining quality and efficiency.In order to solve the problem of cylindrical grinding force measurement,the9257B dynamometer was modified and calibrated,and the relationship between the measured grinding force and the actual grinding force was established.Through the cylindrical grinding test of 18CrNiMo7-6 steel,the cylindrical grinding force prediction model was established,the effects of grinding parameters on grinding force,main indicators of surface integrity(residual stress and roughness)were investigated.The results show:(1)The cylindrical three-stage grinding force model established by considering the process of sliding,plowing and chip formation has high accuracy and can provide a theoretical basis for the research of the influence of grinding parameters on the cylindrical grinding force,and can realize the calculation of sliding force,plowing force and chip formation force.Further analysis can be found that the sliding force accounts for the largest proportion of the cylindrical grinding force,reaching more than 60%.The tangential force in the plowing is 45.4%of the normal force on average,which is smaller than the sliding and chip formation.The difference in the growth rate of the normal force and the tangential force in the plowing is the largest.(2)The rotation speed of the workpiece has a small effect on the grinding force,residual stress and roughness,the grinding force increases with the increase of the radial feed speed of the grinding wheel and the grinding width,the residual compressive stress decreases with the increase of the grinding width,the residual compressive stress first decreases and then increases with the increase of the radial feed speed of the grinding wheel.S_q andS_z first increase and then decrease with the increase of the radial feed speed of the grinding wheel.(3)In the presence of grinding fluid,within a specific parameter range,the cylindrical grinding force plays a major role in the formation of residual stress,and the residual compressive stress is obtained,but the depth of the influence layer generally does not exceed 50?m.