SU1581757A1 - Method of hardening ends of rails using rolling heat - Google Patents

Abstract

This invention relates to ferrous metallurgy, in particular to the heat treatment of railway rails. The aim of the invention is to increase the productivity of the process. At the exit from the mill, the peal stops before specially installed cutting devices and water jet quenching devices, which are installed so that the sections corresponding to the ends of the rails after cutting to length are subjected to quenching, and the areas not subjected to quenching, equal to cutting width and tolerance for subsequent machining of the ends. Then, the cutting of the roll into measured lengths and the quenching cooling of local sections along the length of the roll are simultaneously performed.

Description

This invention relates to ferrous metallurgy, in particular to the heat treatment of railway rails.

The purpose of the invention is to increase the productivity of the process.

Example. The implementation of the method in the production of rails P50 in the conditions of the rail-beam shop of the metallurgical plant. According to the conditions of production, four rails with a length of 12.5 m are obtained from a single roll. To cut the roll into dimension, three hot saw blades are used. For quenching, jet-type quenching apparatus is used with a quenching zone limited.

At the end of the rolling, the roll coming out of the mill is fed to the hot cutting saws, the technologically necessary cutting of the front end is made,

after moving the roll until it stops, it is fixed in this position. The distance from the stop to the saw and the distance between the saws are the same with the calculation of the production after cooling and completion of all finishing operations of the rails with the required length standard (12,500 + 6 mm). The roll on the live roll is located in the position on the side of the head to the saws. Next to the saws (on both sides of each saw), as well as at the front and rear ends of the roll, there are eight quenching machines that can be moved in a direction perpendicular to the longitudinal axis of the roll. Quenching machines near the saws are installed in such a way that between adjacent hardened areas there remains a zone that is not quenched, the length of AO mm

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the axes of symmetry of which are cut by a saw. Quenching machines near the stop and the first along the rail movement are exposed with respect to the roll so that the contact point (quenching spot) on the rails is located 15 mm from the end. The choice of the parameters of the length of the non-hardened zone and the distance of the quenching point to the end face is determined by the conditions of the subsequent milling of the ends (removal of metal on average 15 mm) and the width of the cut (10 mm). After fixing the roll, before the saws, all quenching machines are supplied to the sections corresponding to the ends of the rails after cutting. At the moment of contact of the quenching apparatus with the roll, water is automatically switched to all the machines and cooled. At the same time with. start of motion of quenching apparatus

The saw was supplied to the peal and the beginning of cutting was combined with the beginning of cooling. After the end of the cutting, the length of the saw is returned to its original position, while the cooling process continues (cutting time 30 s, quenching time 55 s). When the cooling is completed, the water supply is stopped and the quenching devices also return to their original position. Cut three

the rail is removed by a shlepper to the anti-flocking processing section, and the remainder with a hardened spot on the head corresponding to the length of the last (fourth) rail cut from the roll is fed under the support and the rear trim is cut off with a saw. Thus obtained rails have a hardness, configuration and depth of the hardened layer within the requirements of the standard.

When using the proposed method increases the productivity of the process.

Claims (1)

Invention Formula The method of hardening the ends of the rails with rolling heating, including cooling the surface of the rolling head in local areas along the length of the roll, corresponding to the ends of the rails after cutting, leaving between the adjacent hardened areas of the zone not subjected to cooling, the length equal to the width of the cut and the size of the tolerances for subsequent processing of the ends and cutting the roll through these zones into measured lengths, which is different, in order to increase the productivity of the process, cooling the surface of the Katani head and cutting the roll through t the same time.