Residual stress control method of hundred-meter heavy rail

Abstract

The invention relates to a residual stress control method of a hundred-meter steel rail, which belongs to the fields of prebending deformation control and composite straightening deformation control processes of the hundred-meter steel rail and the like. The invention adopts a method with universal rolling, cooling after rolling and composite straightening, and large-radian prebending is adopted for the hundred-meter steel rail in the cooling process after rolling, so that when the steel rail is cooled to the room temperature, the chord height is controlled in the range of 30-40mm. By combination of optimized straightening deformation rules of an 8+1 multi-roll straightening machine and the control of the curvature before straightening, the residual stress control method effectively controls the residual stress of the bottom of the rail after the hundred-meter steel rail is straightened, the residual stress values of the bottom of the rail are averagely reduced by 70MPa, all the residual stress values are less than or equal to 250MPa, and the straightness of the steel rail is improved, so that the qualification rate of the steel rail is improved, and the standard requirement of the hundred-meter steel rail is met.

Description

technical field [0001] The patent of the invention relates to a method for controlling the residual stress of a 100-meter rail, which belongs to the fields of pre-bending deformation control, composite straightening deformation control technology, and the like. Background technique [0002] At present, the production steps of the 100-meter rail are usually used: universal rolling, post-rolling cooling, and compound straightening. The cooling process of the 100-meter rail after rolling is different due to the different cooling rates of different parts of the cross section, resulting in shrinkage deformation and phase change expansion. The time is different, so that the rail will repeatedly bend towards the rail head and the rail bottom during the cooling process, and finally the rail will have obvious bending deformation and residual stress after cooling, and the bending deflection has exceeded the size of the traditional cooling bed, which not only makes the Steel rail can't...

AI Technical Summary

Problems solved by technology

[0003] The traditional rail cooling bed itself can no longer meet the technological needs of the 100-meter rail and is facing elimination

The traditional rail cooling bed adopts a steel-drawn cooling bed, a DC motor drive system, and manual operation. It is difficult to achieve synchronization between the head and the tail of the rail, and it is easy to cause scratches on the rail.

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