Numerical Simulation And Optimization Of Casting Process For QT450-10Axle Housing

As the basal part for installating differential, speed reducer and wheel hub,axle housing bears a larger impact and friction in the process of work, so it musthave good comprehensive mechanical properties. In this paper, the casting processof nodular iron axle housing of forklift is studied. The mould filling process andsolidification process were simulated by numerical simulation softwareInteCAST.The main reasons of casting defects in the designed casting process wereanalyzed in order to optimizing the casting process. Finally, the casting defects areeliminated and the high-quality axle housings can be acquired by the optimizingcasting process.Firstly, the preliminary process scheme was put forward according to thematerial requirements and the structure characteristics of the QT450-10axlehousing casting. Then, the filling and solidifing process under the preliminarycasting process was simulated by using InteCAST software. The changing rule ofthe flow field and temperature field of the casting were analysed. The simulationresults show that much shrinkage porosity is found at the feeding area and halfshaft parts in the axle housing casting. All of shrinkage volume in the casting is79.33cc. The total shrinkage cavity volume of0.07cm3is found on the bottom endcover parts and top convex platform parts.The initial process scheme is adjusted by changing the height and diameter ofthe riser. And the solidification process under the improved process was simulated.The simulation results suggested that increasing the height and diameter of the riserwas not effective to improve the feeding effect of the riser, and the shrinkage cavityand porosity in the casting can not be eliminated completely. The casting process isfurther adjusted by changing the size of the riser neck length and the riser necksection. The simulation results showed that the riser neck solidification time wasdelayed and the feeding channel was expanded by reducing the riser neck lengthand increasing the cross section of size riser neck. As a result, the feeding effect ofthe riser is improved, and the shrinkage porosity of the feeding area was reduced to 45.00cc.The rest of the shrinkage porosity was found in the half shaft parts. Byincreasing casting subsidies on the half shaft parts, a gradually increasingtemperature gradient from the half shaft to the riser is formed. The effective riserfeeding distance is increased and the shrinkage volume in the half shaft parts waseliminated to10.43cc.The shrinkage cavity and porosity in the casting was eliminated successfullyby setting the cold iron and air outlet. By placing a cold iron near the bottom endcover parts of the casting in the mold, the solidification velocity was accelerated inthe thick wall place, and the isolated liquid zone in the thick wall was avoided.Then the shrinkage cavity on the bottom cover parts was eliminated. For theproblem of producing Shrinkage cavity and porosity on the top parts of the casting,by placing air outlet and vent piece there, the shrinkage cavity and porosity on thetop parts can be eliminated effectively.In this paper, an optimized casting process scheme with shrinkage cavityeliminated completely was receieved by simulation analysis. The volume ofshrinkage porosity has been reduced to6.74cc by the improvement of process.