If there is a thin layer of skin on the surface of the casting after shot blasting, which can be easily picked off by hand, and the size, area and position are not fixed, this phenomenon is called peeling after shot blasting in die casting.
Why is the casting peeling after shot blasting? After years of experience in shot blasting, the following six situations are summarized:
1. The casting is not compacted, and there are casting defects such as cold shut, delamination, bubbles and poor fusion of alloy flow on the surface.
2. The steel shot ejection speed is too high.
3. The shot peening time is too long.
4. The hanging parts are unreasonable, unstable and collided with each other.
5. The shape and quality of steel shot are poor and not smooth.
6. The steel shot contains sharp impurities.
In the face of these situations, we should deal with them as follows:
1. The casting surface is dark. Inform the die casting process or the Engineer in charge to adjust the die casting process parameters or equipment parameters;
2. Appropriately reduce the steel shot ejection speed of the shot blasting machine;
3. Reduce shot peening time appropriately;
4. Reasonable hangers shall be used to ensure that the casting is fixed during shot peening, and special fixtures can be used when necessary;
5. Purchase steel shot with regular shape;
6. Screen the steel shot or replace the steel shot.
7. Lead shot can be replaced if conditions permit.
Steel shot is widely used for descaling and rust removal treatment
How are steel shot and grit used to treat steel surfaces?
Steel shot is widely used for descaling and rust removal treatment
What are the unique characteristics of steel shot?
