Running fire generally occurs in sand casting. Check 《investment castingManual, actually did not run the fire this defect. However, there are running defects in the two books "Handbook of Casting Defects and Countermeasures" and "Practical Investment Casting Technology" compiled by Jiang Bju, and both are under the details of investment casting defects. Todayprecision castingManufacturer Yufeng Metal will talk about what causes the fire.

Running fire, as the name implies, is the fire ran out. The fire here actually refers to high-temperature molten metal. Because the temperature of the molten metal is high, it is similar to fire in terms of color and temperature, so the word "running fire" came into being. Since it can run fire, it means that the shell has a channel for running fire, that is to say, the strength of the shell is not enough, which creates an opportunity for the metal liquid to escape. So, what are these channels and what are the causes?

1. to the fact that the product's hole or deep groove is dry and opaque or the shell-making operation is poor, the bridge is formed, resulting in insufficient high-temperature strength of the shell, and finally under the action of high-temperature metal, the shell or crack or rupture, which eventually leads to the fact that the shell is scrapped.

In the process of dewaxing, handling or roasting of 2. products, the shell is cracked due to bumping, which eventually leads to the shell running fire and the casting scrapped.

3. the casting shell thickness design is insufficient, the shell directly breaks in the process of pouring metal liquid, resulting in the formation of fire defects, resulting in casting scrap.

The thermal shock resistance of the 4. shell is poor, and it directly cracks when the metal is poured, forming the fire defect. This phenomenon is often encountered in quartz shells.

In addition, it should be noted that there is a defect similar to running fire, that is, high-temperature metal flow comes out of the mold shell during pouring. However, only a small amount, the shape of the casting is intact, and the casting can still be used after cleaning and polishing. We distinguish this defect from running fire and call it shell leakage. The difference between it and the fire is that the castings are not scrapped, but more cleaning and polishing efforts.

We can see from the above several situations that there are many reasons for the shell to run, such as the operational level, for example; The first case and the second case mentioned above; There are design aspects, such as: the third case; There are also the quality of raw materials and so on. These are the details that we need to pay attention to in our usual work, so we must do a good job in the details to ensure the quality of the shell, so as to reduce the production of running defects.

The fundamental way to improve the defect of running fire is to make the shell well and get rid of the bad operation habits, which will not be repeated here. Yufeng Metal, a Jiangmen precision casting manufacturer, was established in 2003. It is an outstanding supplier of precision casting, precision casting, all-silica sol investment precision casting and CNC numerical control machining. It provides joint development and one-stop customization services from mold manufacturing to precision casting production. It is committed to providing high-quality precision casting for China's high-end manufacturing industry. If you have any questions about precision casting and precision casting, please consult us!