Rolling technique capable of lowering depeth of steel rail decarburized layer

Abstract

The invention relates to a rolling technique capable of lowering depth of a steel rail decarburized layer, which belongs to the technical field of steel rail rolling production and is used for solving the technical problem of complex control on the heating procedure due to the lowering of the depth of the decarburized layer in the prior art. The technical scheme is as follows: the technique comprises the following steps: continuous casting billet heating, high-pressure water descaling, BD1 rolling mill cogging, BD2 rolling mill cogging, descaling by high-pressure water rough rolling, universal mill rolling and UF finish rolling. The technique is characterized in that the continuous casting billet heating adopts a walking beam heating furnace, wherein the preheating section temperature is lower than 900 DEG C, the heating section temperature is 1160-1260 DEG C, the heat soak section temperature is 1220-1250 DEG C, the temperature difference between thermocouples on both sides of the heating furnace is at most 30 DEG C, and the heating time is 3.5-4.0 hours. By controlling the temperatures of the preheating section, heating section and heat soak section of the heating furnace, the depth of the steel rail surface decarburized layer is controlled at 0.18-0.41mm and 0.21mm on average, thereby satisfying the standard requirement. The technique is simple to control.

Description

technical field [0001] The invention relates to a rolling process capable of reducing the depth of decarburization layers of rails, and belongs to the technical field of rail rolling production. Background technique [0002] According to the relevant railway development information, my country's railway mileage has now grown to 91,000 km. In 2020, it is planned to be 150,000 km. Therefore, heavy rail steel will have great demand for a long time in the future. Research has become the key focus area of ​​various iron and steel enterprises. Due to the high carbon content of heavy rail steel, the oxidation and decarburization of the steel billet is serious during the heating process, and the decarburization of the rail will reduce its performance, such as the decline in mechanical properties, hardness, wear resistance and fatigue strength, etc., and these performance declines will be Seriously affect the driving safety of high-speed and heavy-duty trains; for this reason, how to...

AI Technical Summary

Problems solved by technology

In order to reduce the decarburization depth of the rail surface as much as possible, the Chinese patent CN103614527B controls the decarburization depth by controlling the billet heating rate and defining the decarburization depth calculation formula of the rail head. Although the purpose of the invention is achieved to a certain extent, the content of the invention It only reduces the depth of the decarburized layer of the rail head, but does not mention the decarburized layer of the rail waist and rail bottom. In the actual operation of the rail, the depth of the decarburized layer of the rail waist and rail bottom also affects the train The driving safety has a great impact; and the calculation formula for the decarburization depth of the rail head established by the invention does not give a detailed test inference analysis, and the heating control process control is also relatively cumbersome

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