The heat treatment of gray cast iron can only change its matrix structure and cannot change the shape of graphite. Therefore, the heat treatment cannot significantly change the mechanical properties of gray cast iron, and the low plasticity of gray cast iron makes it difficult to implement the rapid cooling heat treatment method, so the heat treatment of gray cast iron Big limitations. Its heat treatment is mainly used to eliminate stress and improve cutting performance.

1. Annealing stress relief (aging treatment)-low temperature annealing. Put the casting in a furnace of 100 ~ 200 ℃, slowly increase the temperature to 500 ~ 600 ℃, keep it cool for 4 ~ 8h.

2. Annealing to improve cutting performance-high temperature annealing, reduce hardness, heat the casting to 850 ~ 900 ℃, keep it warm for 2 ~ 5h, and slowly cool to 400 ~ 500 ℃ for air cooling.

3. Surface quenching-improve hardness and wear resistance