Temperature Field Simulation Of Hollow Ingot Solidification Process

In recent years our country vigorously promote energy conservation,sustainable development strategy,hollow ingot application has been all-round attention.Compared to solid steel ingot,the hollow ingot eliminating upsetting,punching and other mechanical processing sectors, material utilization has been significantly improved. Under laboratory conditions to carry out simulations hollow ingot solidification temperature field,explore the impact of factors coagulation process,provide an important theoretical basis for the production of high quality hollow ingot.In this paper sized hollow ingot solidification process for the study. Using ANSYS software simulation of the hollow ingot solidification temperature field, determine suitable cooling medium and the heat transfer coefficient.To simulate the solidification temperature field as the initial target, it was designed simulation apparatus, and through the hollow ingot mold filling simulation process validated, get the following conclusions:(1)The mold design consists of the outer mold,the mold,sand mold and core four parts according to the process parameters hollow ingot.The size of ingot within mold thickness 20 mm,an outer diameter of the outer mold ingot 1580 mm,the top outer mold inner diameter 1270 mm, the bottom of the outer mold inner diameter 1160 mm,300mm thick sand mold.The mold core is mainly composed of the core,strut and pads of three parts,the inner mold welding strut integrally for med annulus.(2)By volume fraction diagrams and flow field pattern of filling process can be seen,Set the calculated internal diameter of the sprue 100 mm,inner diameter of the runner 100 mm,inner diameter of the inner runner 100 mm, the casting speed is 22.3mm/s and other parameters.Increased speed steel liquid interface is relatively stable and does not appear splash defects,even in the initial stage of the filling it is very stable,consistent with theoretical needs.(3)With the increase of heat transfer coefficient, the trend hollow ingot solidification gradually moving to the inner and outer symmetrical,final solidification position tends to the upper.When the heat transfer coefficient is 170 W /(m2.k) at best.(4)The annulus width and volume flow combined effect of heat transfer coefficient of the cooling medium,so these two factors were studied.When the annular gap width is constant,the heat transfer coefficient with increasing volume flow increases;When the volume flow rate is constant, the smaller the width of the annulus greater heat transfer coefficient.Comprehensive analysis when the ring gap width is 30 mm,the volume of air flow 8900 m3/h can be achieved the optimal heat transfer coefficient 170W/(m2.k).