Simulation Study Of Secondary Oxidizing Slag And Casting Process Optimization For Hub

Hub castings,as an important component of wind turbines,are subjected to large working loads and operate in harsh environments.Therefore,higher demands are placed on their organization and mechanical properties.It is necessary to design a reasonable casting process scheme and cooperate accordingly.Production conditions can guarantee the quality of its casting.This thesis analyzes the structural characteristics and technical requirements of the hub,based on the basic principles of the casting process design,and uses the three-dimensional software to complete the casting process of the hub casting.The Flow 3D simulation software was used to simulate the temperature field,velocity field and pressure field of the filling process of wheel hub castings.According to the velocity field and the velocity of the in-gate water inlet,it was analyzed whether serious metal splashing occurred during the early filling stage.The turbulence phenomenon,based on the pressure field to determine whether the erosion phenomenon,combined with the comprehensive analysis of the speed criteria and pressure criteria,to complete the preferred casting production process program suitable for wheel casting production.The smelting process and pre-furnace treatment are the roots of casting primary slag.The slag treatment can completely remove the primary slag,and the pouring process is the key stage of secondary slag formation.Based on the RNG dual equation turbulence model,this paper compares and analyzes the physical parameters such as the average mass turbulent kinetic energy,average mass turbulence dissipation rate and turbulent shear generation term in the three casting process schemes.Using the Flow 3D surface defect tracking model,the secondary oxidizing slag concentration changes during the filling process of the three schemes are compared and analyzed.According to the secondary slag concentration criterion,it can be seen that the top surface of the hub casting and the corners of the blade holes are The possibility of secondary oxidized slag on the bottom of the cavity is high.When the inner sprue is directly facing the convex surface of the hub,the secondary oxidizing slag concentration at the corner of the blade hole can be effectively reduced,and the secondary oxidizing slag concentration at the bottom of the cavity can be reduced by appropriately increasing the filling rate.When the runner is in the unfilled state,the direction of the speed is disorderly and the secondary oxidizing slag concentration of the inner runner is high;when the runner is in the full-fill state,the direction of the speed tends to be the same,and the secondary slag of the inner runner is then The concentration has a minimum value and gradually stabilizes.This paper adopts the Flow 3D simulation calculation method,combines the actual production of the factory with the turbulence speed criterion and the criteria of secondary slag slag defects.The optimized casting process scheme can effectively reduce the occurrence of secondary slag defects and non-destructive testing of wheel castings.The standard has provided reliable theoretical guidance for the practice of casting production,shortened the trial production period of the castings and improved the production rate of the wheel castings.