How to solve the problem of Casting porosity?

1.1invasive stomata

(1) Reduce the amount of gas generated: Control the content of gas-generating substances in the molding sand orcore sand. The moisture content of the wet molding sand should not be too high, and the amount of release agent and water should not be excessive during modeling and mold repair. The sand core should be dried. The sand core after drying should not be stored for a long time. The sand core used the next day should be dried in the oven before use to prevent the sand core from absorbing moisture. Do not use damp and rusty cold iron and core. Hold up.
(2) Improve the air permeability of the sand, select the appropriate air tightness, reasonably arrange the position of the air outlet to facilitate exhaust, and ensure that the sand core ventilation channel is unobstructed.
(3) Properly increase the pouring temperature, open the exhaust holes and exhaust risers, etc., so as to facilitate the gas invading the metal liquid to float up and discharge.

1.2 precipitated stomata

(1) Adopt clean and dry charge materials, and limit the use of charge materials with large gas content.
(2) Make sure that the tapping trough, tapping port and bridge are completely dried.
(3) The ladle should be dried, and it is best to be ironed before use. There is iron in the bag. Be sure to put a covering agent on the surface of the iron.
(4) When various additives (spheroidizing agent, inoculant, covering agent) have high humidity, they can be used only after drying.

1.3 subcutaneous stomata

(1) Properly increase the pouring temperature, strictly control the amount of various additives, and shorten the pouring time as much as possible.
(2) Prevent the molten iron from oxidizing, add relay coke appropriately, and strictly control the air intake.
(3) On the premise of ensuring spheroidization, the amount of spheroidizing agent should be minimized.
(4) Cover the cryolite powder on the surface of the molten iron during pouring to prevent the molten iron from oxidizing
(5) Minimize the moisture in the sand.
(6) Increase pouring speed.