Numerical Simulation Of Temperature Field Stress Field Of Piston Rod Surfacing In Hydraulic Support Column

In coal mining production,hydraulic support is the core equipment of fully mechanized mining face.Due to the poor working environment,the piston rod on the hydraulic support is easily damaged and corroded,which leads to the decrease of coal mining production efficiency and even causes great losses when coal mining cannot be carried out.Considering the above problems,it is necessary to study and analyze the repairing technology of piston rod,and surfacing welding is an applicable repairing method.Therefore,this thesis with the piston rod welding as the research object,based on ANSYS software platform,established the finite element model of the piston rod,using APDL programming and element birth and death to simulate the piston rod welding temperature field and stress field,analyses the preheating,cooling conditions and welding speed on the influence of the temperature field,microstructure transformation,result of stress and deformation of welding condition.The results show that the preheating can increase the temperature of the molten pool,narrow heat source center and the temperature difference of heat affected zone,reduce the temperature gradient,and the cooling time will be extended accordingly,preheat temperature should be controlled at 150 ?.High speed welding will shorten the residence time of high temperature,resulting in insufficient heat transfer and incomplete fusion pool.Low speed welding will produce overheating phenomenon,resulting in uneven welding layer;Medium speed welding can ensure the quality of the welding layer and obtain good microstructure,so the welding speed can be set as0.007m/s.When the convection coefficient is set as 100,the cooling speed is relatively high,which facilitates the transformation from supercooled austenite to martensite directly,and is conducive to improving the hardness of the welding layer and the wear resistance,so as to extend the service life of the piston rod.In addition,in areas where the stress changes greatly,the amount of deformation is also large.