Numerical Simulation And Process Improeent Of Oil Supply Shell Casting

Oil supply shell casing is one of the important parts on the ship,the product is in use will absorb a certain amount of load and friction,so there is a high machining precision demand inside the hole surface,it requires a good sealing after the assembly,and there shall be no casting defects.During the initial development of the product,it was found that the defects such as inclusion,shrinkage and shrinkage of the castings seriously affected the product quality.Because the requested delivery cycle is short,this paper adopts the methods of numerical simulation experiment and field test of combining the technical route,and it simulates the liquid filling and cooling solidification process to predict and analyze the tendency of the casting defects,location,and the reasons for the appearance of casting flow.On the basis of the numerical simulation experiment,the process improvement and physical test mode are adopted to make a reasonable casting process to meet the needs of customers,so as to ensure the smooth completion of production tasks.The results show that:(1)For the casting materials QT450-10(C3.5~3.8,Si2.6~2.8,Mn≤0.3,P≤0.06,S≤0.03),this paper chooses Fe Si Mg8 RE as nodulizer,BS-1A as inoculants to nucleate and nodulize,during which pour.over nodulrizing treating process is adopted when nodulized.(2)This paper raises the pouring temperature to 1380℃.Cold spruing can help increase the filling quality of cast dressing.(3)Cold orifice setting in casting iron can make the riser neck liquid solidified faster,and then closing the feeding channel of the riser faster promptes an isolated liquid phase region(thermal center)and increases the porosity shrinkage tendency.(4)Although the steps of the direct molding casting hole can decrease the difficulty of mold assembly,reduce subsequent machining process and improve the utilization rate of material,step hole structure is not conducive to impurities floating on the casting surface,impurity easily collected in steps,so larger machining allowance should be taken into consideration for the step hole.(5)The second design for process improvement(the pouring temperature raised to 1380℃,cold spruing,non step hole,chiller)works well when mass producing qualified Oil supply shell casting.