Seamless billet cooling method

According to the chemical composition of the seamless steel pipe, the state of the organization, the size of the product section, the defects that may occur after cooling, and rolling, cooling equipment, space and cooling conditions, can be used to cool to room temperature using different cooling methods.


1) Air cooling
This is a natural air-cooling method that is widely used. After all, the air is cooled. It is not a martensitic structure or steel. It uses air cooling after hot rolling, such as mild steel, low-alloy ordinary strength steel, most carbon steel and alloy semi-martensite structural steel, and Austrian Stainless steel, and are all using this cooling method.


2) Fast cooling
It is the process of blowing, spraying and water that is forced by the cooling method. It is characterized by cooling to the natural temperature in a certain period of time. For example, it is required to use this cooling method to test carbide stencil defects. The carbon steel wire is also cooled rapidly after rolling to improve the overall mechanical properties of the wire.


3) Slow cooling
It is characterized by hot-rolled steel sheets or stacked together so that it cools slowly to prevent white point defects. The specific method is to slowly cool according to the production conditions, and special slow cooling pit can be used. It can be moved in a special slow cooling box, stacked on the floor, covered with asbestos insulation material such as sand, slag, etc., and slowly cooled. . This is cold


However, the method is applicable to half of the martensite, martensite, and the glauberite steels, such as high-speed tool steels, stainless steels, tool steels, and high-alloy high-profile alloys, and their generated stresses are very sensitive to cold.


4) Heat treatment
The commonly used methods after heat treatment are hot rolling annealing, tempering and normalizing.