What are the common cooling methods for forging?

What are the common cooling methods for forging?

1. Air cooling: put forged forgings in air to cool (but place forgings should not have strong airflow and should be kept dry). This method is suitable for small forgings of low and medium carbon steel and alloy structure steel.

2. Pit cooling: the forged forgings are buried and filled with sand, slag, lime or asbestos pit cooling, this cooling method is slow, suitable for medium carbon steel, alloy tool steel and most of the low alloy steel medium forgings, and carbon tool steel forgings need air cooling to 700℃ ~ 650℃, and then pit cooling.

3. Furnace cooling: put the forged parts into the heating furnace at 500℃ ~ 700℃ immediately, and cool with the furnace. This is the slowest cooling method, suitable for medium carbon steel and low alloy steel large forgings and important parts of high alloy steel. In general, the higher the carbon content and alloying element content of steel, the larger the volume, the more complex the shape, the slower the cooling rate should be.