With the rapid development of automobile industry, the production and sales of engine are also increasing year by year. As one of the main parts affecting engine performance, crankshaft has become the focus of attention. Crankshaft requires not only high comprehensive mechanical properties, but also high heat resistance and wear resistance, earthquake resistance and pressure reduction; Nodular cast iron crankshaft is generally produced by casting and can be designed; And the raw materials and production cost are low. Therefore, the application of nodular cast iron crankshaft is expanding day by day, and the research on the preparation technology of high-performance nodular cast iron crankshaft has also become one of the hotspots.
Iron mold sand coating process is a process with the advantages of both sand mold casting and metal mold casting, but the iron mold manufacturing is difficult and costly. Therefore, the numerical simulation analysis of iron mold sand coating process in the early stage can effectively predict the flow of molten iron during mold filling and the temperature field during solidification, and judge the location of possible casting defects, It can not only provide reliable reference suggestions for the improvement of casting process, but also shorten the trial production cycle of iron mold and reduce the cost and waste of resources.
Ultrasonic treatment of solution refers to the method of applying ultrasonic treatment to the solution before or during metal solidification to affect the solidification structure and properties of metal through acoustic cavitation, acoustic flow and thermal effect. Ultrasonic treatment is a kind of physical field treatment, which meets the requirements of environmental protection, and can effectively refine the grain, make the structure uniform, remove the pores, and improve the macro and micro segregation of castings. The water simulation method was used to explore the energy efficiency of power ultrasound, and the experiments of ultrasonic treatment of nodular cast iron melt were carried out in the laboratory and factory, in order to obtain the ideal microstructure of high-performance nodular cast iron.
(1) Numerical simulation calculation and process optimization of iron mold sand coating solidification process of nodular cast iron crankshaft;
(2) By analyzing the rising temperature of aqueous solution under the action of ultrasound and the breakdown effect of ultrasound on aluminum foil paper in water, the ultrasonic output energy efficiency of probes of various materials and sizes is compared;
(3) Ultrasonic treatment technology of ductile iron flame body can purify molten iron, refine microstructure, improve performance and yield.