Causes of slag inclusion and segregation in copper casting and its prevention
The slag inclusion of copper casting is caused by the serious contamination of the furnace charge, or the improper charging sequence, which will lead to slag inclusion if the slag amount is large; moreover, the slag inclusion of copper casting is caused by the low refining quality, the low slag removal capacity of the casting system, or the secondary oxidation and pouring temperature Too low degree and slag floating will also lead to slag inclusion in copper casting.
For the slag inclusion of the copper casting to be prevented by the above methods, first of all, it should be noted that the smelting process should be strictly carried out, and then the amount of returning material should be limited; after that, it should be noted to adjust the feeding sequence; after that, it is necessary to select the appropriate refining agent for refining; improve the pouring In the design of the system, the filter screen and the slag collecting bag are used; finally, attention should be paid to prevent the secondary oxidation.
The main reasons for the segregation of copper castings are uneven mixing, low pouring temperature, and low cooling rate. As for the segregation of copper casting caused by these reasons, it is necessary to fully mix before pouring, and then reduce the pouring temperature.
In order to prevent the segregation of copper castings, it is necessary to pay attention to improve the cooling speed of the mold. It is common to use graphite mold or metal mold and water-cooled mold. Then, in terms of its prevention method, it is necessary to pay attention to the technology of stir casting, vibration casting and pressure casting.
Shrinkage cavity and porosity of copper casting are caused by too high or too low pouring temperature, too fast or too slow pouring speed, or improper design of pouring system, insufficient feeding effect of riser, etc.; for the prevention of shrinkage cavity and porosity of copper casting caused by this time, attention should be paid to adjust the pouring temperature and pouring speed.