Reserarch On Both The Filling Process And The Cooling Analysis Of Nodular Iron Crankshaft With Iron Mould Coated Sand

Iron mould coated sand which is a new method to obtain high quality castings is developed rapidly in recent years, and has been listed by the state mechanical department as a key promotion in Eight-Five project. This casting method combines the advantages of the metal mould and the sand mould casting:a higher casting dimension precision, less flash burr, with sand amount only about1/25of the sand mold casting method commonly, high-yield, metal mold life is long, etc. At present, the technology has been more and more the favor of foundry enterprises, a large number of casting manufacturer are being in improvements or building a casting of iron mould coated sand production line. As the degree of automation and mechanization are increasing, and production batch is bigger, while it is possible for casting shrinkage, shrinkage, slag inclusion and other issues, the loss is becoming relatively larger than ever. Since iron mould coated sand casting cost too much on the tooling investment, and the testing process, and too many difficulties on modify, it make a sense to research on the numerical simulation of the optimization of casting process of iron mould coated sand, as far as possible to predict casting possible defects such as shrinkage, shrinkage, slag inclusion before the tooling manufacturing.Iron mould coated sand can provide a more ideal casting cooling environment by adjusting the thickness of the coating and iron type. It will become more difficult in parameter Settings before the numerical simulation progress. We can hardly obtain accurate simulation results using ordinary sand mold casting to make an approximation of iron mould coated sand casting. To make the simulation results more accurate, coating and iron type are defined respectively in this study to apply in the numerical simulation of filling and solidification cooling process.Proportional solidification theory is one of the focuses of attention in recent years. It has a very important guiding significance in runner system optimization design. The theory system elaborated the contraction of the casting expansion regularity in casting process, and different ways of feeding and the formation mechanism of shrinkage porosity defect for different alloy and casting type. By the theory of proportional solidification, filling solidification simulations of different gating system and predict shrinkage defects have been made by taking a flywheel of ductile iron casting for example in this study. Different gating systems on casting porosity shrinkage defects and the affections have been analyzed to explore the gating system design method of riserless casting technology of iron mould coated sand. The rationality of the design of gating system has been validated by experimental analysis.The significance of the research on cooling process is to make full use of waste heat to normalizing of ductile iron casting, to achieve high mechanical properties. As-cast ductile iron has remarkable energy saving effect, casting performance, saving equipment investment, shorten the production cycle, and low rejection rate, also can avoid the heat treatment of high temperature oxidation and deformation, etc. As-cast nodular cast iron becomes a new trend of development of ductile iron material.Cooling temperature of the nodular cast iron crankshaft in different open-time was measured in this study to make the cooling curve. Analysis found that out of the time at10-15min out as the best out of the time, while it often be measured more than20min in the process of production. By analyzing the cooling curves compared with the simulation results, the parameter Settings have been improved to provide a more accurate simulation for casting process simulation of iron mould coated sand.