2. The second is the change in the basic organizational structure. The first heat treatment procedure is mainly used to eliminate internal stress, which is caused by different cooling conditions and conditions during the Stainless Steel Casting process. The structure strength and other mechanical properties are not significantly changed due to heat treatment.

Regarding the second type of heat treatment, al-Qaeda has undergone significant changes and can be roughly divided into five categories:
1. Softening annealing: The main purpose is to decompose carbides, reduce their hardness, and improve workability. For ductile iron, the purpose is to obtain more ferrite structure.
2. Normalizing treatment: The main purpose is to obtain pearlite and sorbite to improve the mechanical properties of stainless Steel Casting.
3. Quenching treatment: mainly to obtain higher hardness or wear strength, and at the same time to achieve very high surface wear resistance.
4. Surface hardening treatment: The main purpose is to obtain a surface hardened layer and at the same time to obtain a very high surface wear resistance.
5. Precipitation hardening treatment: The main purpose is to obtain high strength without drastically changing the elongation.