Strict control of pouring temperature and casting speed are prerequisites for obtaining qualified castings

In order to obtain a qualified casting, the casting temperature, casting speed must be controlled and the pouring operation rules must be strictly observed.

1. Pouring temperature: A reasonable pouring temperature range should be determined according to the type of alloy, the structure of the casting and the characteristics of the casting. When the molten metal is poured into the ladle from the furnace, the temperature is lowered. In order to reduce the temperature inside the bag, the repaired ladle must be fully dried, preheated before pouring; try to avoid the bagging, reduce the residence time of the metal in the bag and shorten the transportation distance; the wall of the ladle can be made of high-efficiency insulation material. After the molten metal is discharged from the furnace, the slag covering agent is added to the liquid surface of the bag; the temperature measurement is strengthened, and the temperature drop and the pouring temperature of the molten metal in the bag are strictly monitored.

2. Pouring points: Before pouring, the slag on the metal surface of the ladle should be removed; the pouring should be carried out according to the specified speed and time range; the splashing and interruption of the metal flow should be avoided during the pouring; the slow pouring should be started, and the pouring cannot be performed. Gate, so as not to destroy the sand type; fast pouring in the middle to fill the casting system; the gate cup should always maintain a certain amount of molten metal to prevent slag and gas from entering the mold; when filling quickly, it should be slowly poured to prevent overflow and reduce Lift the box force. For castings with risers, point casting and refilling should be carried out later in the casting. Care should be taken to ignite the gas discharged from the mold after pouring. After the casting is solidified, the pressure iron and the box card are removed in time to reduce the shrinkage resistance of the casting and avoid cracks.