Numerical Simulation And Experimental Study On Differential Temperature Thermal Treatment Of High Chromium Cast Iron Rolls

With the development of China’s iron and steel industry,as well as the continuous progress and competition of roll production technology at home and abroad,the quality and performance of various types of rolls have higher requirements.The roller body of high chromium cast iron with composite centrifugal casting has high hardness and wear resistance,while the core has good toughness.But the rollers with excellent performance cannot be obtained without scientific casting and heat treatment.In the process of differential heating in traditional differential heating furnace,high chromium cast iron rolls will have uneven temperature distribution and uneven temperature rise on the surface of the rolls,resulting in uneven hardness of the rolls produced.Therefore,it is necessary to study the process of roll in differential heat treatment furnace,so as to provide basic data for optimizing and improving differential heat treatment furnace and improving roll quality.The main research contents of this paper are as follows:Firstly,according to the differential heating characteristics of the roll differential heating furnace,the non-premixed combustion model is selected by FLUENT software in ANSYS and combined with the characteristics of the high-speed tangential combustion nozzle of the differential heating furnace,and the Realiable k-ε turbulence model,DO radiation model and slip grid model are adopted.Finally,a three-dimensional fluid-solid coupling heat transfer model is established,and the differential heating process of the roll in the differential heat treatment furnace is simulated by this model,and the flow field in the differential heat treatment furnace and the temperature field of the roll are analyzed.Secondly,design the experimental scheme of roll differential heating treatment,and actually measure the temperature in the furnace and the temperature of the roll body during the process of differential heating in the differential heating treatment furnace,and compare with the numerical analysis data to verify the accuracy of the simulation.Thirdly,in view of the problems found in the actual production and simulation,the inlet law of the differential thermal treatment furnace was adjusted and the structure was reformed,and the simulation scheme was designed.The FLUENT software was used for numerical simulation for several times,and the roll body temperature data obtained by simulation under each scheme was compared,and the scheme with the best uniformity of roll body temperature distribution was obtained.