There are mainly five types of heat treatment processes:
1. Quenching: Heating the steel pipe above the critical temperature and then rapidly cooling it to form a hard and brittle martensitic structure, which can improve strength and hardness of steel pipes.
2. Tempering: Preheat the quenched steel pipe to an appropriate temperature, slowly cool it to eliminate internal stress, adjust hardness, and improve plasticity and toughness.
3. Normalization: Heat the steel pipe to the normalizing temperature to completely transform the internal structure into austenite, and then cool it, which can eliminate stress and improve hardness and cutting performance of steel pipes.
4. Annealing: Heat the steel pipe to the annealing temperature, hold it for a period of time, and then slowly cool it to reduce hardness, improve plasticity, facilitate subsequent processing, while eliminating stress and improving structure.
5. Solution treatment: Heat the steel pipe to the solution temperature to fully dissolve carbides and alloying elements in the austenite, then rapidly cool to obtain a single austenite structure, eliminate work hardening, and restore corrosion resistance.
