December 11, 2019 by gongda
Stainless steel castings are no stranger to us, but it is difficult to control the size in our production process. Any carelessness will result in inaccurate size. So what are the factors that make it inaccurate in size? The main factors are as follows.
1. Structure of the casting: the wall of the casting is thick, the shrinkage rate is large, the wall of the casting is thin, and the shrinkage rate is small. 2. Shell-making materials: zircon sand, zircon powder, Shangdian sand and Shangdian powder are used, because their expansion coefficient is small, it is only 4.6×10-6/℃.
3. Roasting of shell: due to the small expansion coefficient of stainless steel casting shell, when the shell temperature is 1150℃, it is only 0.053%.
4. Casting temperature: the higher the pouring temperature, the greater the shrinkage rate, the lower the pouring temperature, the shrinkage 5. Casting material: the higher the carbon content in the material, the smaller the linear shrinkage rate of stainless steel castings, the lower the carbon content, the greater the linear shrinkage rate of stainless steel castings.
6. Linear shrinkage rate of casting caused by molding: wax injection temperature, wax injection pressure and holding time have the most obvious influence on the size of the investment mold, followed by wax injection pressure. Holding time has little influence on the final size of the investment mold after the investment mold is formed. Linear shrinkage rate of wax material is about 0.9-1.1%.
All of the above will affect the dimensional accuracy of stainless steel castings, therefore, we should pay special attention in the future production process.
Shenyang Gongda Heavy Equipment Manufacturing Co., Ltd., A Prominent and Highly Recognized Manufacturers and Suppliers of High Quality Metal Castings. For more information on castings, please contact us: https://www.wearresistantcasting.com/