Annealing: Annealing is to heat the casting to the appropriate temperature, according to the material and casting size of the use of different insulation time, and then slowly cooling it, the purpose is to make the metal internal structure to achieve or close to the balance state, get good process and performance, or for further quenching structure preparation in advance. Normalizing: Normalizing is to heat the casting to the appropriate temperature and then cool it in the air. The actual effect of normalizing is similar to annealing, but the structure is finer. It is often used to improve the cutting performance of the material, and occasionally used as a final heat treatment method for some parts with low demand. Quenching: Quenching is the rapid cooling of castings in quenched media such as water, oil or other inorganic salts and organic aqueous solution after heating and holding the castings. After quenching, the steel becomes hard but brittle at the same time. Tempering: in order to reduce the brittleness of steel parts, the quenched steel parts are kept warm for a long time at an appropriate temperature higher than normal temperature but less than 750℃, and then the petroleum casing manufacturers cool them down. This kind of processing technology is called tempering.
The current heat treatment method of steel grade petroleum casing is weak in hardenability during production and processing. The material mechanical properties of steel pipe are not very good, and the actual effect of protective bending is not good, and it is very easy to fracture. The heat treatment method of petroleum casing should be strictly carried out. The manufactured petroleum casing has good product quality and characteristics, and presents good value and characteristics in use. It insists on high strength and toughness, and carries out heat treatment method in different methods. At the same time, the low temperature quenching is lower than the conventional temperature, which reduces the quenching stress and then reduces the quenching deformation, so that the smooth operation of the production of oil casing heat treatment method, and provides a good raw material for the subsequent production and processing of wire