1. Ingredients selection: In general, pump body sand Castings with small wall thickness are not easy to form ferrite, which is easy to produce white mouth. Increasing the silicon to carbon ratio can effectively prevent the formation of a port at the thin wall, which is beneficial to improve the uniformity, strength and hardness of the casting structure and reduce the residual stress.
2. Charge requirements: In the production, 3t/h two-row large-pitch cupola is used for smelting. Locally produced coke and pig iron can be added, and 5%~15% scrap can be added. The thickness of scrap steel is ≥3mm, and the blockiness is greater than 1/5 of the diameter of the furnace. It is required to be rust-removed. The rest of the furnace block is not more than 1/3 of the diameter of the furnace. In order to reduce the burning loss of silicon, iron alloy with lower silicon content is selected as much as possible. In order to ensure the melting temperature, coke with a higher fixed carbon should be used, and the blockiness should be between 90 and 130 mm.
3. Melting operation: An important indicator for obtaining high-quality molten iron is the boiling temperature of molten iron. Especially for high-silicon-carbon than cast iron, the melting temperature is high, which is beneficial to reduce the burning of silicon, but it will increase the tendency of carbon increasing. Therefore, it should be considered that during the smelting, the bottom height is appropriately increased, the air volume is increased to increase the melting rate, and the tendency of the iron to increase carbon is controlled. While obtaining high temperature molten iron, the carbon content is controlled within an ideal range.https://www.pump-casting.com/