Give you a detailed introduction to the bottom pipe finishing rolling pipe need not heat, the purpose is what, in the square pipe processing process, each stage is indispensable, this process is all the work experience summarized by the ancestors, people must master, below the people will discuss the actual problems at this stage.

The purpose of heating in the heat treatment furnace is:

1) Improve the plastic deformation of steel and reduce the deformation resistance. In general, the plastic deformation of steel is weak at ultra-low temperature, and its deformation resistance is great, while the plastic deformation of steel is good at high temperature, and the deformation resistance is small. The mechanism of carbon square tube blank at normal temperature is metallographic structure + cementite. When the finishing rolled pipe is heated, it will change with the increase of temperature. When the steel temperature exceeds the zero boundary point, the internal mechanism of the finishing rolled pipe will change from two-phase mechanism at normal temperature to single-phase electric mechanism ferrite. At this time, the plastic deformation of steel is good, and its deformation resistance is greatly reduced, which is easy to carry out working pressure production and processing.

2) Improve the mechanism characteristics of steel and make its mechanism symmetrical. During the process of ferritization at high temperature, in addition to the change of the metallographic structure of the body-centered cubic meter lattice laser into the ferrite of the body-centered lattice laser, the destruction of the cementite lattice laser is also accompanied by the melting into the ferrite, and the external diffusion of carbon atoms in the ferrite, so that the composition and mechanism of the ferrite are further symmetrical. Within a certain temperature range, the ferrite can be symmetrical and grow, so that the size of the ferrite grain tends to be symmetrical and consistent. In that way, it is not only beneficial to the symmetrical deformation of heat treatment, but also improves the internal organization structure of steel to a certain level. In addition, the prerequisite for the controlled cold rolling of some alloy structural steels is created.

3) It is conducive to cleaning up harmful substances and impurities in steel. When the finishing rolled pipe is heated, the atmosphere in the furnace can be properly controlled, so that the harmful substances in the steel can be cleaned by the diffusion effect of high temperature. Some mixed or strip mechanisms are melted or diffused according to high temperature diffusion, which is convenient for symmetrical dissolution after rolling.

Because of the characteristics of the ground stress conditions of the cross rolled holes, there is a rupture temperature range for a certain alloy structural steel to ensure the quality of the capillary. Therefore, the heating temperature of the finishing rolled tube of alloy structural steel is determined by the hole breaking temperature.