Copper alloy smelting operators should wear protective equipment, keep the working environment clean and tidy, no water and dirt allowed; (2) Before the furnace, check whether the commonly used machinery and equipment are intact. If there are unsafe elements, they should be removed immediately; (3) should be carefully and ensure that there is no inflammable, explosive and dangerous materials in the waste of the furnace, before heating: (4) smelting and pouring special tools, such as cooking rod, iron spoon, slag discharge special tools can not touch with aluminum alloy liquid; ⑤ The remaining aluminum alloy liquid should be poured into the heated ingot mold and then poured on the road or inverted smelting.
Smelting should pay attention to many problems 1. Smelting time should be manipulated from the beginning of the feeding melt to the end of the melting of exactly P) commonly used time is called melting time. The length of melting time will not only harm the production efficiency, but also significantly harm the casting quality. Melting time, will make aluminum alloy elemental ablation rate increase, the opportunity to improve respiration, therefore, should be Z less time for melting work. The heating temperatrure of the remelting waste should be increased as much as possible under allowable conditions.The practical operation should be compact and the posture should be fast.
The cooking rod used in smelting should be some elements in the carbon rod alloy copper, such as Fe.Pb, etc., are stored in the form of mechanical equipment compounds when melting. Some elements, because of the different relative densities, have the tendency to cause the development of proportional shrinkage and porosity layers. Practical experience shows that in the whole process of smelting and pouring, this element is very easy to cause composition failure, resulting in poor physical performance. To get rid of this kind of situation, it is necessary to rely on the effect of mixing, which is an essential stage of molten casting. But in the temperature measurement and temperature reduction period, generally do not mix. And the commonly used raw material composition of the mixture, generally should use high purity graphite. This is because, if the application of other mixing materials such as iron bar, iron bar melting in the whole process of mixing, so that the composition of aluminum alloy suffer harm. In addition, if the iron bar in the furnace heating temperature is higher or mixing time is longer, the metal oxide on the iron bar into the aluminum alloy liquid into the residue; If the temperature of iron bar heating is lower, aluminum alloy should be attached to the iron bar when mixing, which can be observed in the production and manufacturing.
For smelting copper alloy, the amount of covering agent used is generally: 0.8%-1.2% of the net weight of refurnace waste when using covering agent, because to maintain the thickness of soil layer is 10-15mm; When using wood carbon, the amount used is 0.5%-.0.7% of the net weight of the recycled waste. It is necessary to maintain the soil layer thickness of 25-35 mm to remove the covering agent, which is generally carried out before pouring. Premature development will improve the air oxidation and respiration of alloy copper. If you use wood carbon as a covering agent, and the actual effect of slag blocking is better, you can also not remove the covering agent, so that it has slag blocking effect in the whole process of pouring, the actual effect is more ideal.
It is not allowed to sample the surface layer of liquid copper to carry out the characteristic experiment. Copper is easy to breathe by air oxidation, and the composition of slag and gas in the liquid level is significantly higher than that in the next layer of liquid copper. In addition, some aluminum alloys such as aluminum bronze and lead brass are very easy to shrink and loosen, resulting in more aluminum components with relatively low density at the upper end of liquid copper, and more lead content at the lower end. Therefore, the characteristic experiment of liquid copper surface sampling is not accurate. Proper sampling The liquid metal material shall be scooped up from the bottom end of the clamp pot with a sampling spoon after sufficiently mixing the liquid copper. In addition, the actual effect of DFCT-4 cleaning agent is more remarkable.
