How To Control The Pouring Temperature Of Valve Castings?
How to control the pouring temperature of valve castings?
Every year in the production of valve castings, often due to casting temperature scrap castings accounted for about 20%, casting temperature is closely related to casting quality, therefore, to improve the yield of the valve castings, you need to control the pouring temperature.
1, the highest pouring temperature value. High pouring temperature will cause sand-type rise, especially with complex sand core castings, when pouring temperature 1420 when the scrap is increased, pouring temperature of 1460 Shan waste up to 50%. Therefore, the highest casting temperature should be controlled under 1420 Shan.
2. Lowest pouring temperature. When the pouring temperature is below 1380 Shan, the small pores of each monomer will be found under the surface of the machined cast iron, and the diameter of the hole is generally 1. In individual cases there are only 1-2 small holes, and these holes will also appear with a small amount of liquid slag. The results show that this defect is related to pouring temperature, and when the pouring temperature is higher than 1380 Shan, the defect will not be produced in the valve castings.
To sum up, it can be seen that casting temperature should be controlled in 1380. In addition, the most common cause of low pouring temperature is that before pouring, the molten iron is transported and stayed in the open ladle for a long time. The heat loss can be significantly reduced by pouring the cover with an adiabatic material.