1. Firstly, raise the temperature in the furnace to 1650-1680 ℃ to ensure the carbon silicon.

2. Weigh the alloy  put it into the casting bag,  then add the silicon iron content coating at 30 / 40mm.

3. Pour 1 / 3 of the original molten iron first,  then add 2 / 3 of the molten iron after the reaction.

4. Adding the corresponding amount of ferrosilicon at the same time of introducing the pouring ladle for secondary inoculation.

5. The slagging time  driving time shall be shortened as much as possible to make the molten iron rush into the box quickly.

6. The negative pressure shall be kept at a constant temperature. After pouring, the pressure shall be maintained according to the casting conditions,  then it shall be discharged  the box.

It should be noted that the temperature required for different castings is different,  the holding time  out of box time are also different. A reasonable configuration based on the castings can achieve good results.