5 common defects and solutions such as casting shrinkage holes, surface roughness and lack of finish
2024-08-03
Porosity phenomenon (including bubbles, choke holes, air pockets) Causes: 1, mold preheating temperature is too low, liquid metal through the pouring system cools too quickly. 2、Bad mold exhaust design, poor gas discharge. 3, bad paint, poor exhaust, or even volatile or decomposition gas. 4, There are holes and pits on the surface of the mold cavity. After the liquid metal is injected, the gas expands rapidly and compresses the liquid metal, forming choking holes. 5、The surface of the mold cavity is rusted and not cleaned up. 6、Improper storage of raw materials (sand core), not preheated before use. 7、Bad deoxidizer, or insufficient dosage or improper operation. The following are short methods to prevent gas holes (bubbles, choke holes, air pockets): 1, within the appropriate range to control the pouring temperature, to avoid gas expansion is too high. 2、Mold preheating sufficiently, using good permeability, appropriate particle size...
