Study On The Process Of Plasma Arc Surface Strengthening

Plasma arc surface quenching is a common surface heat treatment technology.And plasma arc surface quenching equipment is often combined with the lathe,or manual quenching.The former cannot be quenched for giant workpieces,and the latter cannot accurately process complex surface workpieces.In this paper,the four joint plasma arc surface hardening robot can quench large parts with complex surface.Establish its structure model based on the SimMechanics toolbox in the MATLAB Simulink Library.Calculate of end effector velocity and acceleration data for position coordinates,and draw the working space and the speed of image acceleration.Finally,the typical steel parts are quenched experimentally.Plasma surface quenching process have very quick speed of heat up and cooling,so it is difficult to directly measure the real-time temperature change of the workpiece through such devices as thermal imagers.The differential equation of heat conduction treated by quenching is used as the theoretical basis.Simulation of surface quenching process of plasma arc by finite element ANSYS Workbench software.And with a small amount of tests to verify the accuracy and reliability of numerical simulation results.Comparing the simulated data with the experimental data to verify the reliability of the simulation process.This article focuses on the law of the depth and width of the hardened layer changing with different process parameters.Change the process parameters.The prediction of the depth and width of the corresponding hardened layer on the basis of the simulation results of the quenching temperature field.Drawing the predicted value into the influence of different factors on the hardened layer,and fitted the function relation.It provides a mathematical reference for the optimization of the actual plasma arc surface quenching process parameters.The simulation results are of high accuracy compared with the experimental results.The depth and width of the hardened layer increase with the increase of the arc power,and decrease with the increase of the plasma arc moving speed.Selecting the excessive arc power and scanning speed can improve the machining efficiency,but too fast scanning speed makes the workpiece quenched incomplete and uneven.The small arc power and scanning speed are selected to make the workpiece surface melt.Precision of surface quenching process of plasma arc.The influence of thermal physical parameters variation and latent heat of phase change on the simulation precision of temperature field is emphatically analyzed.The selection of constant thermal physical parameters makes a large error in simulation calculation.Considering the effect of latent heat of phase change,the depth of the hardened layer is reduced.While the thermal physical parameters vary with the temperature and the latent heat of the phase change is considered,the results of the hardened layer obtained by the simulation are basically in agreement with the practice.