Forging Simulation & Interfacial Transfer On Diesel Engine's Crankshaft

Because of large torque transmission,stable working condition and high performance cost ratio,diesel engine is widely used in the traditional machinery industry,marine transport,energy,power industry and other equipment.Because crankshaft works in the high temperature and high pressure environment,and bears large torque transmission and alternating stress,so the requirement in the strength and rigidity is higher.Due to the complicated structure and high performance requirement,the control of crankshaft's forging process often has higher requirements.During the forging process,the initial and final forging temperatures must be strictly controlled to ensure the smooth formation of the crankshaft and effectively improve the crystal granularity.Therefore,the use of finite element numerical simulation to predict the temperature field is essential during forging process.In this paper,finite element numerical simulation and experimental method were used to take a model crankshaft as an example to study the temperature field during the whole forging process.That predicted the temperature,and analyzed the law of temperature,the metal flow and equivalent stress during the entire forging process.And it made experiment to check crankshaft's reliability and has instructive significance.The following was main research contents.(1)The 42 CrMo steel's material model in the finite element numerical simulation of crankshaft forging process was checked.The thermal conductivity,specific heat capacity,thermal diffusivity,young's modulus,shear modulus,poisson's ratio,linearity thermal expansion,average thermal expansion coefficient and other thermal properties parameters were measured.(2)Based on Deform-3D's Inverse Heat Transfer and experiment,the heat transfer coefficient between blank and air was calculated,and the heat transfer coefficient between the blank and the air was checked during phosphorus removal process,and the correctness of the heat transfer coefficient was verified.(3)For the purpose of predicting the temperature field,the finite element numerical simulation and experimental verification were completed during the whole process of crankshaft forging.The heat transfer coefficient between the blank and the mold was checked,and the law of temperature,the metal flow,equivalent stress and equivalent strain were analyzed,and the correctness of the heat transfer coefficient is verified.In order to prevent engine failure by the crankshaft's fatigue damage,so it made crankshaft's bending fatigue test.