부산대학교 도서관

Throughout the present study, guaranteed soundness of heavy section spheroidal graphite cast iron has been pursued bymeans of a reliable C and Si ranges design. For this purpose, the three main parameters of superheating temperature, mushyzone and total volume change during solidification are chosen to calculate the optimized range for casting soundness usingthe conventional thermodynamic software. As a result, a triangle region of C and Si allowable range, where C content isover 3.7 wt%, Si content is over 1.3 wt% and carbon equivalent value is below 4.5 wt%, was obtained by superimposingthe individual C and Si range of each thermodynamic parameter for the prevention of casting defects. In order to verifythe calculation results, a comparative study was performed with a previous study, and test castings were performed both atlaboratory scale and mass production sites. Regarding the laboratory casting, various casting defects were observed off thecalculated allowable ranges. Within the calculated allowable ranges for the guarantee of the sound casting, both laboratoryand mass production castings revealed an absence of defect.