Shrinkage is a common brake disc defect. For brake disc safety parts, its performance and safety are greatly affected. So how do we prevent the brake disc from shrinking during use?
Firstly, the molten iron can be evenly introduced into the inner runner to reduce the local overheating of the disc and prevent the formation of artificial hot joints. According to the view of balanced solidification of the cast iron parts, the thinner the smaller the larger the shrinkage value, the more emphasis should be placed Shrink. The filling method can adopt the pouring system for filling, and the feeder can also be set for feeding.
When the filling system of the pouring system can also be used, the head of the sprue can be appropriately increased, such as increasing the height of the upper box, adding the gate ring, etc .; the cross-runner is the main unit for skimming and floating air. , Can be appropriately heightened to increase its cross-sectional size: the inner runner should be made into short, thin and wide shapes, the inner runner is short (the runner is close to the casting), affected by the heat of the casting and the runner, and the molten iron In order to fill the effect of shrinkage flow effect, the inner runner will not be solidified and closed in advance, and it will remain unblocked for a long time. The thinness can prevent the formation of contact heat joints at the introduction of the inner runner. The width is to ensure sufficient overflow area.
If the brake disc has serious shrinkage, a riser can be set to compensate. The riser should be located at the beginning of the inner runner as much as possible, or a riser can be installed at the middle core to the disc part on the side of the inner runner. Implement backfilling. For thin-walled small pieces, secondary inoculation measures can be adopted, that is, inoculants are added to the packet for instant inoculation, which improves the inoculation effect, promotes the growth of graphite nucleus, is added to the bottom of the package, and is poured into the molten iron.