Multifunctional heat treatment system for steel pipe

Abstract

The invention discloses a multifunctional heat treatment system for a steel pipe. The heat treatment system comprises six groups of roller paths, a medium-frequency induction furnace device, a high-temperature resistance furnace device, an ultra fast cooling device, an outward sprinkling and inward spraying device and a low-temperature resistance furnace device, wherein the six groups of roller paths consist of a feeding roller path group, a medium-frequency induction heating roller path group, an air cooling roller path group, an ultra fast cooling roller path group, an outward sprinkling and inward spraying roller path group and a discharging roller path group which are arranged in sequence; the medium-frequency induction furnace device is arranged between two adjacent roller paths of the medium-frequency induction heating roller path group; the high-temperature resistance furnace device is arranged on one side of the air cooling roller path group; the ultra fast cooling roller path group is arranged in the ultra fast cooling device; the outward sprinkling and inward spraying device is arranged on one side of the outward sprinkling and inward spraying roller path group; and the low-temperature resistance furnace device is arranged on one side of the discharging roller path group. According to the system, the whole process line is compact in design, the operation is simple and convenient, needed equipment can be combined and selected according to process requirements, and various heat treatment process requirements of the steel pipe are met.

Description

technical field [0001] The invention belongs to the technical field of steel pipe heat treatment, in particular to a multifunctional heat treatment system for steel pipes. Background technique [0002] The traditional steel pipe heat treatment heating method is mainly gas heating and resistance heating, which consumes a lot of energy. During the heating process, due to the slow heating rate, the work efficiency is not high, and the heating time is long. Steel pipe surface quality. The heating time of the steel pipe is long, the microstructure of the steel pipe is difficult to be refined, and the performance improvement is limited. Considering the continuous and automatic heat treatment process and the good surface quality and high straightness of the steel pipe after heat treatment, it is the best choice to use medium frequency induction heating to heat treat the steel pipe. Induction heating has the advantages of fast heating speed, energy saving, environmental protection ...

AI Technical Summary

Problems solved by technology

[0002] Traditional steel pipe heat treatment heating methods are mainly gas heating and resistance heating, which consume a lot of energy. During the heating process, due to the slow heating rate, the work efficiency is not high, and the heating time is long. Steel pipe surface quality

The heating time of the steel pipe is long, the microstructure of the steel pipe is difficult to be refined, and the performance improvement is limited

Considering the continuous and automatic heat treatment process and the good surface quality and high straightness of the steel pipe after heat treatment, it is the best choice to use medium frequency induction heating to heat treat the steel pipe. Induction heating has the advantages of fast heating speed, energy saving, environmental protection and automation. The heating degree is high, the heating process is easy to control, and the manufacturing cost is high. However, this heating method also has the problems of limited holding time and poor temperature uniformity of the steel pipe as a whole.

[0003] In the production process of small and medium-diameter steel pipes, it is generally only necessary to hot-roll or weld large-diameter steel pipes of several specifications, and to produce various specifications of small- and medium-diameter steel pipes through the tension reduction process after reheating to expand the product specification range , improve production efficiency; but after the intermediate reheating process, the austenite phase transformation will re-occur in the pipe structure, and the temperature after tension reducing rolling is greater than Ar 3 (Generally around 850°C), if the subsequent phase transformation is not controlled, it will easily cause the internal structure of the steel pipe to be coarse and the performance will be reduced. It is necessary to use appropriate controlled cooling technology to control the phase transformation after reheating and rolling to improve Microstructure of steel pipe after hot-stretching

At present, the steel pipes after reducing are mostly air-cooled on the cooling bed, the cooling capacity is limited, and the degree of improvement to the structure and performance is limited.

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