According to the chemical composition of seamless steel pipe, different cooling methods can be used, such as national organization, product cross-section size, possible defects after cooling, rolling, cooling equipment, space and cooling conditions after hot rolling. Cool to room temperature.


1) Air cooling
This is a natural air cooling method, which is widely used. All air-cooled steels are not martensite or steel, but air-cooled after hot rolling, such as low carbon steels, low alloy ordinary strength steels, most carbon steels and alloy semi-martensite structural steels and austenitic stainless steels, and this cooling method is being used.


2) Rapid cooling
It is blowing, spraying, water is forced through the steel-making process of cooling method, its characteristic is to cool a certain period of drama to the natural temperature after cooling. For example, this cooling method is required to test the defects of cemented carbide steel mesh. Carbon steel wire can also be rapidly cooled after rolling to improve the overall mechanical properties of the wire.


3) Slow cooling
It has hot-rolled steel plates or stacked together to slow down cooling and prevent white spot defects. Specific methods according to production conditions, slow cooling pit can be used for special slow cooling pit, which can be moved in a special slow cooling box, to be stacked on the floor, with sand, slag and other asbestos insulation layer for slow cooling. It's cold.


However, the method is suitable for martensite, martensite and semi-ledeburite steels, such as high-speed tool steels, stainless steels, tool steels and high-alloy cross-section high-alloy structures, which are very sensitive to the stress generated during cooling.


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