Temperature Field And Thermal Deformation Simulation Research Of Vacuum Furnace

With the continuous development of vacuum heat treatment technology,vacuum heat treatment furnaces have been widely used.The furnace is the core component of the vacuum furnace,which has a great influence on the performance of the vacuum furnace.Vacuum furnaces with metal furnaces are mainly used to process precision parts and special alloy materials that require high cleanliness.The metal furnace is more expensive,has larger heat loss,and is complicated to manufacture.Therefore,it is of great practical significance to analyze and study the temperature field and thermal deformation of the vacuum furnace furnace,which can provide a reference for the development of new equipment and the improvement of equipment performance.According to the theory of heat transfer,the heat transfer mode of the metal furnace heat shield is mainly radiation heat transfer.Taking the metal furnace of the WZDGQ 40 vacuum furnace as a reference,the simulation software is used to simulate the temperature field in the furnace.Simulation and structural optimization of thermal deformation of furnace heating belt,charging table and heat shield.Concluded as follow:1)According to the furnace structure,the heat shield adopts three layers of molybdenum and four layers of stainless steel.At 1000 ℃,a simplified model of the furnace multi-layer heat shield was constructed to study the heat preservation effect of the heat shield.By changing the spacing,width and thickness of the heat shield,it is proved that increasing the thickness of the heat shield has little effect on improving the thermal insulation effect of the furnace.A simplified 1/4 symmetrical furnace model was constructed to simulate the uniformity of the temperature field in the effective heating area,and the spacing,width and number of heating strips were adjusted.Taking into account the temperature uniformity of the effective heating area and the thermal insulation effect of the heat insulation screen,the optimal heating belt distribution scheme of the furnace is determined: the six heating belts are evenly distributed with a spacing of 180 mm.2)On the basis of the maximum temperature of 1300 °C,thermal deformation simulation of the heating belt,material table components and heat shield of the furnace is carried out.According to the simulation results,the fixed circular hole of the heating belt is optimized to be an oblong hole of 6 mm,and a reinforcing plate is designed.It is verified that the deformation of the material table group is small under load and high temperature,which meets the requirements of use.According to the simulation study of heat shield deformation,it is determined that the optimal number of supports for each heat shield is 12.When the uniform spacing of the heating belts is 180 mm,the thicknesses of the optimized three-layer molybdenum heat shield from the inside to the outside are: 0.5,0.4,and 0.4 mm,respectively.3)According to the AMS2750 F standard,the existing equipment is used to test the temperature uniformity of the effective heating area in the furnace and the temperature of the outer wall of the furnace.The measured temperature uniformity of the effective heating area of the furnace is less than ±5 ℃,and the system accuracy calibration adopts the comparison SAT method,the temperature difference meets the standard requirements.The temperature of the outer wall of the furnace gradually decreases from the middle to the two sides.Finally,the actual deformation of the furnace metal heat shield and heating belt is introduced,and the deformation position is basically consistent with the simulation.