The strict requirements of the investment casting pouring process

2022-04-26

Pouring process is a very critical process for investment casting. To ensure the casting quality, the pouring operation procedures should be strictly implemented. Here below are some key points which we should pay much attention to during the pouring process.

1.Pouring temperature

Q:  What is the best pouring temperature in general?

A:  The pouring temperature has a particularly great influence on the quality of the casting. The appropriate pouring temperature should be determined according to the type of alloy to be poured, the construction of the casting and the characteristics of the mold. For stainless steel material, under normal circumstances, the pouring temperature should be between 1540-1580 °C.

2.Pouring speed

Q:  What is the best pouring speed in general?

A: The speed of pouring is related to the forming speed of casting. Therefore, under the condition of ensuring the smooth discharge of the gas in the cavity, different pouring speeds are adopted for castings of different standards. In general, we should adopt a faster pouring speed for standard simultaneous solidification stainless steel castings, while for stainless steel castings that achieve sequential solidification, we should adopt a slower pouring speed.

3. All tools in contact with molten iron must be heated in advance, otherwise they cannot be used.

4. When pouring large and medium-sized castings, it should be noted that the molten steel needs to stand for 2 minutes before pouring.

5. The molten iron should not exceed 80% of the volume of the molten iron ladle, and it should be stable when moving to avoid being scalded.

6. After the casting is poured successfully, it is necessary to remove the weight and box clamp immediately after the casting is solidified, otherwise the casting will form cracks.

7. The excess molten iron must be poured into the prepared sand pit or iron film to avoid explosion and injury. If it is splashed on the way during transportation, it must be cleaned immediately after drying.

8. Before use, all equipment should be checked to prevent potential safety hazards and cleaned immediately after use.

Finally, I would like to emphasize that sufficient preparations should be done before pouring to ensure that the subsequent pouring operations can be carried out smoothly. Preparations before pouring include: 

a. Clean up the pouring site to ensure the safe and smooth completion of the pouring process. 

b. Check the quality of the ladle, the drying and preheating, and the flexibility and reliability of the transport and tilting mechanisms.

c. Know the type of casting alloy, estimate the number of molds to be poured and the weight of molten metal required to prevent the phenomenon of insufficient molten metal and insufficient number of molds in pouring.

d. Work clothes and protective goggles.

At present, according to the proportion of castings of various materials, steel castings account for about 12% of the total output of castings, which has a great impact on the development of the entire casting industry. In the casting of steel castings, Stone industrial will try our best to do a good job in all aspects, improve the quality of steel castings, and promote the development of the entire casting industry.