Research On Riser Design Method And Process CAD System For Ductile Iron Shape Castings

Ductile iron has been widely used because of its excellent mechanical property,good casting property and low cost production.The proportion of ductile iron castings in total castings has increased year by year.But because of the graphitization expansion during solidification of ductile iron castings,which exerts pressure on the mold,it is difficult to determine the size of the riser by considering many factors.Moreover,the shape of ductile iron castings is becoming more and more complex,and the position of the riser is difficult to determine,so the riser design for ductile iron castings is difficult.As a result,current casting process CAD systems for ductile iron castings are relatively few and their functions are not perfect.Therefore,the riser design method and casting process CAD system for ductile iron castings with complex shape were studied in this paper.The main work is shown below.Firstly,a riser design method for complex ductile iron castings was established.The riser design method includes getting the position and the size of the riser.A method of getting the position of the riser for complex ductile iron castings was established on the basis of calculating geometric hot spot with distance field.At the same time,based on the moduli calculation method,the factor of mold strength was introduced.The numerical simulation scheme was designed,and the numerical simulation was carried out based on the InteCAST platform.,then the method of calculating the size of the riser for ductile iron castings considering mold strength was established by analyzing and summarizing the data.Secondly,based on the riser design method of complex ductile iron castings,a casting process CAD system for ductile iron castings was developed.According to the casting process,the overall scheme of the system including the architecture,database and function was designed.The design theory and development process of each module(initialization module,process parameter module,riser system module,chiller system module and gating system module)were introduced in detail.Finally,the CAD system was applied to two typical ductile iron castings in an enterprise.The results of numerical simulation and experiments showed that there was fewer shrinkage defect in the castings,and the casting process design including riser design was reasonable.We can get the position and the size based on different mold strength of the riser for ductile iron castings with complex shape.