Production Method for Improving Pickling Performance of Oxidized Iron Scale of High Carbon Steel Wire Rod

Abstract

The invention discloses a production method for improving high-carbon steel wire rod oxide scale acid pickling performance. The production method comprises the processes of finish rolling, reducing and sizing, silking and cooling. In the finish rolling process, the finish rolling inlet temperature is controlled to range from 880 DEG C to 910 DEG C; in the cooling process, four-stage cooling rate control is adopted, wherein a product is placed at the temperature ranging from 700 DEG C to 720 DEG C after being discharged out of a silking machine, and the fan opening is 100%; the second stage is a phase change control stage, the temperature is controlled to range from 700-720 DEG C to 530-550 DEG C, the fan opening is adjusted, and the cooling rate of the wire rod is controlled to range from 5 DEG C / s to 7 DEG C / s; the third stage is a FeO eutectoid reaction control stage, the temperature is controlled to range from 530-550 DEG C to 300 DEG C, and the fan opening is 100%; the fourth stage is a natural cooling stage, the temperature changes into bundling temperature from 300 DEG C, fan cooling is not adopted, and natural cooling is adopted. Eutectoid Fe3O4 on which acid pickling is difficult to achieve is not generated on the interface of Fe and FeO, the whole oxide scale thickness is small, and the high-carbon steel wire rod oxide scale acid pickling performance is improved.

Description

technical field [0001] The invention relates to a production method of wire rods, in particular to a production method for improving the pickling performance of oxide scales of high-carbon steel wire rods. Background technique [0002] When producing steel strands from high-carbon steel wire rods, it is necessary to remove the scale on the surface. At present, there are mainly two methods for removing scale. One is the mechanical peeling method, which utilizes the characteristics of different elongation rates of steel and scale. The oxide scale is broken by the tension leveler to remove the oxide scale, but if the descaling is not clean, the surface of the steel wire will be damaged during drawing, causing broken wires, and at the same time, the wear of the mold will be aggravated, and the life of the mold will be affected. Another method is Pickling descaling method, which utilizes the characteristics that FeO in the iron oxide scale is easy to react with hydrochloric acid,...

AI Technical Summary

Problems solved by technology

[0002] When producing steel strands from high-carbon steel wire rods, it is necessary to remove the scale on the surface. At present, there are mainly two methods for removing scale. One is the mechanical peeling method, which utilizes the characteristics of different elongation rates of steel and scale. The oxide scale is broken by the tension leveler to remove the oxide scale, but if the descaling is not clean, the surface of the steel wire will be damaged during drawing, causing broken wires, and at the same time, the wear of the mold will be aggravated, and the life of the mold will be affected. Another method is Pickling descaling method, which uses the characteristics of FeO in the iron oxide scale to easily react with hydrochloric acid to dissolve it, thereby removing the iron oxide scale

As we all know, the pickling property of iron oxide scale is related to the thickness and structure of iron oxide scale. Under the same structure, the thicker the iron oxide scale is, the more difficult it is to pickle. However, if the iron oxide scale contains a large amount of Fe 3 o 4 , then due to Fe 3 o 4 The reaction with hydrochloric acid is slow, which will make it difficult to remove the iron oxide scale, and if Fe 3 o 4 When the formed part is on the interface between Fe and iron oxide scale, it is more difficult to pickle cleanly. If the iron oxide scale is removed by prolonging the pickling time, the phenomenon of over pickling may even occur, which will affect the subsequent processing.

The high-carbon steel wire rod produced by the ordinary method is controlled according to the cooling rate of the phase change. For example, the cooling rate is the same from the spinning temperature to the end temperature of the phase change. There is a phase transition, and the control of the eutectoid reaction of the scale after the phase transition makes the scale of the high-carbon steel wire rod produced thicker, and there is a eutectoid product of Fe3O4 at the interface between Fe and scale, which affects the high-carbon steel wire rod. Pickling performance of steel wire rod

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