Methods To Improve The Qualification Rate Of Ductile Iron Pipe Fittings
Apr 17, 2022
1. Tube mold
Avoid the thinning of the inner wall of the tube mold, and reduce the speed of the tube mold to make the pockmarked dense and uniform; avoid the inner wall of the tube mold to be too shallow, increase the wind pressure, and grind the nodding, which can make the pockmarks suitable.
For pipe molds with grease and debris on the inner surface, especially for newly used pipe molds, grease and debris on the surface of the pipe mold before use. For pipe molds with tortoise cracks, if it is mild, increase the amount of mold powder added when using it; if the tortoise cracks are serious, change the pipe mold in time.
2. Adjust the position of the chute
For the defect that the tap hole of the chute is improperly shaped or the tap hole of the chute is far away from the socket, it is easy to form a heavy skin on the socket part of the pipe. It is required to check the equipment during production and change the tap hole of the chute. head, and adjust the limit of the centrifuge host when it is in the lower position to shorten the distance between the tap hole of the chute and the socket.
3. Control the temperature of molten iron
It is easy for the temperature of molten iron to be too low, and the temperature of the inner wall of the tube mold is low, which will cause heavy skin defects. The intermediate frequency furnace process should provide molten iron with suitable temperature in strict accordance with the process regulations, and the centrifuge should reasonably control the temperature and cooling speed of the water inlet and outlet during production.
4. Control the speed of the main machine, the amount of turning over the bag, and the speed of the tube mold.
During casting, most of the molten iron flowing out of the chute flows forward, but a small amount of molten iron still flows backwards, and a "flow" appears behind the point where the molten iron falls.
For the quality defects caused by the slow speed of the centrifuge host (slower than the "flow" speed), it is required to shorten the casting time by increasing the speed of the centrifuge host during production.