Analysis Of Fusion Quality Of Composite Centrifugal Casting Rolls And Research On Stress Field Distribution

Composite centrifugal casting has been widely used in the production of double or multilayer composite castings.At present,this technology has been maturely applied in the production of composite steel pipe,composite roll and other products.However,in the composite casting process of double and multi-layer castings,due to the different composition of the middle layer and the outer metal material,there will be poor fusion quality defects between the two metal layers,resulting in the destruction and spalling of the castings,which brings great economic and material loss to the related production.So how to achieve good metallurgical combination between different materials is a problem worth studying.In this paper,the temperature field,flow field and stress field in the process of centrifugal composite casting were calculated,some important technological parameters in the process of centrifugal casting roll production were optimized,and the technological parameters to achieve a good combination between the outer layer and the middle layer of centrifugal composite casting roll were obtained.The main content of this paper is as follows:(1)According to the equipment size of the production site of the enterprise,the threedimensional modeling of the model used in the simulation of the casting process of the centrifugal composite casting roll is completed.The flow field,temperature field and optimized stress field of the outer layer and the middle layer in the composite casting process of the high chromium cast iron roll were simulated by the method of sectional simulation,and the gravity casting process of the roll core was simulated.(2)In the actual production site of the roll,the temperature measuring gun is used to measure the temperature of the outer layer and the middle layer in the actual casting process of the roll at an interval of 50 seconds after the casting stop,and the measured data is compared with the data calculated by the finite element software simulation to correct the heat transfer coefficient in the simulation.The maximum error between the calculated temperature and the measured temperature is 26℃,which verifies the accuracy of the model.(3)Through simulation calculation,when the lowest inner surface temperature of the outer castings is 1035℃ and the casting temperature of the intermediate layer is 1600℃,the casting time of the intermediate layer is 50-60 s.The intermediate layer and the outer layer castings achieve metallurgical fusion,and there is no mixed flow between the two layers of heterogeneous metals.Through the orthogonal experiment of three factors and four levels,the influence sequence of the inner surface temperature of the outer casting,the temperature of the molten metal in the middle layer and the molten metal in the middle layer is as follows: The middle layer liquid metal casting temperature > the inner surface temperature of the outer layer casting the lowest point temperature > the middle layer liquid metal casting time,and the stress simulation of the optimized process conditions was done.From the simulation results,it can be seen that there will be no stress damage in the process.