1, Annealing:

Annealing is to heat the product workpiece to the appropriate temperature. Different holding times can be adopted according to the size of the material and product workpiece, and then it is cooled slowly. The ultimate goal is to make the internal structure of the metal reach or close to the equilibrium state, and obtain better results. Process performance and application performance, or make preparations for deepening quenching.

2, normalizing:

Normalizing is to heat the product workpiece to a suitable temperature and then cool it in the air. The effect of normalizing is similar to annealing, except that the harvested structure is finer. It is often used to improve the cutting performance of the material, and sometimes it is used for some The less demanding parts are treated as final heat treatment.

3,quenching:

Quenching is the rapid cooling in quenching medium such as water, oil or other inorganic salt, organic aqueous solution after heating and holding the product workpiece. After quenching, the steel becomes hard, but at the same time it becomes brittle.

4, tempering:

Tempering is to reduce the brittle fracture of steel parts. The quenched steel parts are kept at an appropriate temperature above the room temperature and lower than 750 °C for a long time, and then they are cooled. The process is called tempering.

At present, the heat treatment process of some steel-grade petroleum casing pipes is poor in hardenability of heat-treated products during processing. The material mechanical properties of steel pipes are not very good, and the protection effect of bending is not good, and it is easy to break. The heat treatment of oil casing must be carried out carefully. The produced oil casing has better product quality problems and performance. It reflects better use value and performance during use, and maintains high strength and toughness. In different ways Heat it up.

At the same time, the low temperature quenching is lower than the conventional temperature, which reduces the quenching stress, so the quenching deformation is reduced, so that the smooth operation of the oil casing heat treatment production, and provides convenience for the later thread processing.