Temperature Field Simulation In Solidification Of Bimetal Composite Pipe With Centrifugal Casting

A transportation pipeline made from common steel materials, which is used in extreme conditions, such as transportation of coal, electric power, petroleum, and chemicals, is often broken before its deadline of serviceable life because of its low hardness, abrasion resistance and corrosion resistance. Actually, it causes pipeline to be wasted, increases cost of products and debases efficiency of pipeline production. It is indubitable that development of national economy needs to utilize cost-effective technology. The bimetal composite pipe with the common carbon steel as outer layer and special materials according to application requirement as inner layer has advantages than the others. The bimetal composite pipe, which extends serviceable life of pipes evidently, can be applied in all fields, and also it is marketable. Due to the advantages of centrifugal casting such as simple process, high efficiency, and casting with reinforced grain, less casting defect, good mechanical properties, and high metallurgical combine strength, it is necessary to investigate the bimetal centrifugal casting process to manufacture composite pipes.This thesis introduces the present research state of bimetal centrifugal casting and numerical simulation technology applied in centrifugal casting and finds out the problems and shortcomings in numerical simulation of centrifugal casting. Based on properties of the process that applied in this research, the 2D physical model of water cooled metal mold centrifugal casting process was built and detailed analysis of the boundary and initial condition are given. The program was written based on FVM numerical method, which can simulate the temperature variation of whole centrifugal casting process in composite pipe production. Therefore, it can provide assistance to centrifugal casting process design of different standard composite pipes. According to calculation results of typical example, the cooling rule of centrifugal casting was obtained. The effect of process parameters on the temperature field of casting was studied.Moreover, mathematical model of 2D inverse heat conduction problem was built and detailed deduced process and program flow chart are described. The instance application indicates that the program can obtain the unknown boundary heat flux based on the finite measured temperature values correctly. Besides, it is introduced to use in calculating the convective heat transfer coefficient between mold and casting. The principle chart of equipment to measure temperature of mold in centrifugal casting machine was designed. As a result, aforementioned mathematical method can make the simulation results more close to the reality.