Part of the casting is incomplete, always appearing in thin-walled parts, the farthest part from the runner or the upper part of the casting. The torn corners are smooth and shiny and not sticky.

Cause:

1. Low pouring temperature,  pouring speed is too slow or intermittent pouring ;

2. The cross-section area of the runner is small;

3. The content of carbon and silicon in the molten iron component is too low;

4. Excessive moisture and pulverized coal content in the molding sand, large gas volume, or high mud content, poor air permeability;

5. The height of the sand mold is insufficient, and the pressure of the molten iron is insufficient.

Solution:

1. Increase the pouring temperature, speed up the pouring speed, and prevent intermittent pouring;

2. Increase the cross-sectional area of the runner and the runner;

3. Adjust the batching after the furnace to appropriately increase the carbon and silicon content;

4. Strengthen the exhaust in the mold to reduce the amount of coal powder and organic matter in the molding sand;

5. Increase the height of the sandbox.