Spray cooling device for long steel rail online quenching unit

Abstract

The invention discloses a spray cooling device for long steel rail online quenching unit. The spray cooling device for long steel rail online quenching unit comprises a strong cooling region and a weak cooling region which are arranged in a quenching unit with the length of 75-125m from front to back, wherein the front part of the quenching unit accounting for one third to one second for the quenching unit is the strong cooling region, an water mist atomizing mode is adopted in the strong cooling region; the back part of the quenching unit accounting for one second to two thirds for the quenching unit is the weak cooling region, an air jetting mode or a mode of blowing compressed air which is humidified in a header pipe or a branch pipe of a ventilation pipeline is adopted in the weak cooling region, and each cooling segment has the length of 1.2-4.5m, is adapted to a distance between two straightened guide rollers and is formed by four cooling units. With the adoption of the spray cooling device, cooling quenching is carried out on the end surface and the two side surfaces of a rail head of a steel rail A and also on the rail bottom below the steel rail A correspondingly, aiming to balance the deformation of the steel rail caused by shrinkage and phase transition during rail head quenching; the steel rail keeps a straight state as much as possible in the quenching process, and the residual stress is weakened. The spray cooling device can be used for effectively controlling the organization and performance of the steel rail within a larger range so as to reach the best heat treatment effect.

Description

technical field [0001] The invention belongs to the technical field of metallurgical equipment, and is aimed at on-line waste heat quenching treatment of steel rails, in particular to a cooling device of a 75-125m long steel rail on-line quenching unit. Background technique [0002] The use of heat-treated rails in railway transportation has a service life of 2 to 3 times that of ordinary hot-rolled rails, which has great economic and social significance. With the development of high-speed and heavy-duty railways, the requirements for rail performance and quality are getting higher and higher. On-line quenching of long-length rails will become the main heat treatment method for rail production in the future. [0003] According to the cooling medium and method used in the on-line quenching of rails, it can be divided into three heat treatment methods: "intermittent water spray", "spray" and "air spray". The advantages of the "intermittent water spray" and "spray" methods are...

AI Technical Summary

Problems solved by technology

The advantages of the "intermittent water spray" and "spray" methods are that the cooling speed is 5~15°C/sec, and the operating cost is low; the disadvantage is that the stability of the working process is poor, and the nozzles will inevitably be blocked, resulting in uneven cooling, and the cooling process cannot be precisely controlled. , the rail head sometimes has abnormal structures such as martensite, causing the rail to be scrapped

"Air jet" is the current mainstrea...

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