Short flow path manufacturing method of heavy rail

Abstract

A short-flow technology for manufacturing the heavy rails with 50 m in length includes such steps as refining molten steel, conticasting, step heating, shaping rolling, fine rolling, sawing by needed size, prebending-cooling, straightening, and inspection. Its advantages are short technological flow, high quality of product and low cost.

Description

(1) Technical field [0001] The invention relates to a method for manufacturing steel rails, in particular to a method for manufacturing short-flow heavy rails, and belongs to the technical field of pressure processing of ferrous metallurgical metals. (2) Background technology [0002] At present, most of the manufacturing methods of steel rails publicly used in China are carried out in large-scale production processes. Steelmaking is used to make blooms or continuous casting billets, which are sent to three-stage continuous heating furnaces to heat cold billets to 1200-1250 ℃, after billet opening in the rough rolling mill, rough rolling and finishing mill rolling into rails, hot sawing, printing, and when the temperature is 550-600 ℃, put it into the slow cooling pit within a limited time, cover and slow cooling for 5.5 hours, then open the pit After another 1.5 hours, the cover is hoisted out of the slow cooling pit for straightening, measuring scale inspection, and then e...

AI Technical Summary

Problems solved by technology

[0003] 1. Most of the blooming slabs or continuous casting slabs provided have high steel inclusions, which affect the quality of heavy rails, and the stability of chemical components is poor. The slow cooling process will inevitably produce white spots due to the inclusion of hydrogen gas, leading to accidents with unimaginable consequences. In addition, during the hot rolling process, it is easy to cause overburning and decarburization in the continuous pusher heating furnace. Due to the multi-purpose pass method, it is difficult to fully extend the rail head and rail bottom, and the quality is poor, which cannot meet the quality requirements of high-speed rails

[0004] High energy consumption for 2 tons of steel: the billet or continuous casting billet is heated and opened, cooled, reheated, and heated by a three-stage continuous heating furnace. The energy consumption of the heating furnace is high, and the energy consumption per ton of steel reaches 2.2GJ. long, burning rate up to 1.1%, CO 2 The emissions are high, and only 120m of mixed coal is consumed per ton of steel 3 Generate and emit more CO 2 The volume is 120×0.368m 3 / t steel, we can see the serious consequences of high energy consumption per ton of steel

[0006] 1) Due to the long heating time and thick iron oxide scale, not only the yield is low, but also the surface quality of the heavy rail is affected;

[0007] 2) The inclined pass method used in the rolling process affects the shape and precision of the rail head and rail bottom due to the difficulty of rolling adjustment, which makes it difficult to improve the quality of heavy rails;

[0008] 3) After straightening, the heavy rail has a blind spot in the straightening, and there are uneven and defective parts. In this case, the defective part has to be cut off, and the yield will be affected by changing the ruler;

[0009] 4) The hot-rolled heavy rails are severely scratched, affecting the surface and shape, and the quality of the heavy rails is poor;

[0010] 5) The level of quality control inspection and testing equipment is poor, there is a lack of inspection and testing methods, the correction equipment is not effective, the quality of cold processing lines and rail end milling, drilling and quenching heat treatment is poor, and it is difficult to improve

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