Cooling method of high strength band steel and device

Abstract

The invention discloses a high-strength strip steel cooling device, which comprises: an entrance roller; an exit roller; High-concentration hydrogen cools the steel strip; several water-cooled stabilizing rolls are sequentially arranged on the running path of the strip to be cooled between the entrance roll and the exit roll, and the strip to be cooled passes through a set of water-cooled stabilizing rolls in turn and is cooled by water The stabilizing rolls are cooled, and the strip steel forms a wrap angle when passing through the water-cooled stabilizing rolls; among them, the water-cooling stabilizing rolls are arranged in pairs, and multiple high-hydrogen high-speed nozzles are arranged between every two pairs of water-cooling stabilizing rolls, and each water-cooling stabilizing roll The opposite side of the roller provides a high flow high hydrogen velocity nozzle. The cooling method of the present invention belongs to the dry cooling method, and the average cooling rate is as high as 200 / S°C (for 1.0mm steel strip), the cooling is uniform, and a good strip shape after rapid cooling can be guaranteed.

Description

technical field

[0001] The invention relates to the field of heat treatment of iron and steel materials, and more specifically relates to a "dry" rapid cooling method for continuous annealing of strip steel or a hot-dip galvanizing production line. Background technique

[0002] With the enhancement of people's awareness of environmental protection and the continuous improvement of driving safety requirements, the steel for automobiles is developing towards high strength.

[0003] Generally speaking, high-strength cold-rolled sheets and hot-dip galvanized sheets are produced by continuous annealing units and hot-dip galvanizing units respectively. Must have rapid cooling capability (water quenching, high hydrogen high-speed jet cooling or roller cooling, etc.). The typical process flow of continuous annealing of high-strength cold-rolled sheet is:

[0004] Uncoiling-cleaning-heating-soaking-slow cooling-rapid cooling-aging (tempering)-secondary cooling-low temperature water...

Examples

example 1

[0053] Example 1, the total length of the cooling zone combined with high hydrogen jet cooling and roller cooling is 9m, and the thickness of the strip to be cooled is 0.8mm. When the high-temperature strip steel after soaking and slow cooling enters the combined cooling zone of the present invention through the pinch rolls, the wrapping angle of the strip steel and each water-cooled stabilizing roll is basically the same, and by controlling the water-cooled rolls to insert The depth stabilizes the wrap angle θ at about 60°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 75% at a high speed at a flow rate of about 140m / s to the surface of the high-temperature strip in operation to rapidly cool the strip. The ultra-high-speed and large-flow back-blowing airflow velocity at the wrap angle of the steel and water-cooled stabilizing roll can be greater than 150m / s (for example, 170m / s), so that the strip can be fully cooled,...

example 2

[0055] Example 2, the thickness of the strip to be cooled is 1.5mm. When the high-temperature strip steel after soaking and slow cooling enters the patented combined cooling zone of high-hydrogen high-speed jet cooling and roll cooling through the pinch rolls, the wrap angles of the strip steel and each water-cooled stabilizing roll are basically the same, and the insertion of the water-cooled rolls is controlled The depth stabilizes the wrapping angle θ at about 70°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 80% at a high speed at a flow rate of 160m / s to the surface of the running high-temperature strip to rapidly cool the strip. The ultra-high-speed and large-flow back-blowing airflow velocity of 190m / s at the wrap angle of the water-cooled stabilizing roll greatly improves the average cooling rate of the strip. Because the strip steel is relatively thick, a lower strip speed V=180mpm=3m / s is adopted. At this t...

example 3

[0057] Example 3, the strip thickness to be cooled is 1.2mm. When the high-temperature strip steel after soaking and slow cooling enters the patented combined cooling zone of high-hydrogen high-speed jet cooling and roll cooling through the pinch rolls, the wrap angles of the strip steel and each water-cooled stabilizing roll are basically the same, and the insertion of the water-cooled rolls is controlled The depth stabilizes the wrapping angle θ at about 65°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 75% at a high speed at a flow rate of 150m / s to the surface of the running high-temperature strip to rapidly cool the strip, and set it on the strip The ultra-high-speed and large-flow back-blowing airflow at the wrap angle of the water-cooled stabilizing roll is 180m / s. At this time, the medium belt speed V=240mpm=4m / s is adopted. At this time, the three-stage high hydrogen jet cooling section, roll cooling and bac...

technical field

[0001] The invention relates to the field of heat treatment of iron and steel materials, and more specifically relates to a "dry" rapid cooling method for continuous annealing of strip steel or a hot-dip galvanizing production line. Background technique

[0002] With the enhancement of people's awareness of environmental protection and the continuous improvement of driving safety requirements, the steel for automobiles is developing towards high strength.

[0003] Generally speaking, high-strength cold-rolled sheets and hot-dip galvanized sheets are produced by continuous annealing units and hot-dip galvanizing units respectively. Must have rapid cooling capability (water quenching, high hydrogen high-speed jet cooling or roller cooling, etc.). The typical process flow of continuous annealing of high-strength cold-rolled sheet is:

[0004] Uncoiling-cleaning-heating-soaking-slow cooling-rapid cooling-aging (tempering)-secondary cooling-low temperature water...

Examples

example 1

[0053] Example 1, the total length of the cooling zone combined with high hydrogen jet cooling and roller cooling is 9m, and the thickness of the strip to be cooled is 0.8mm. When the high-temperature strip steel after soaking and slow cooling enters the combined cooling zone of the present invention through the pinch rolls, the wrapping angle of the strip steel and each water-cooled stabilizing roll is basically the same, and by controlling the water-cooled rolls to insert The depth stabilizes the wrap angle θ at about 60°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 75% at a high speed at a flow rate of about 140m / s to the surface of the high-temperature strip in operation to rapidly cool the strip. The ultra-high-speed and large-flow back-blowing airflow velocity at the wrap angle of the steel and water-cooled stabilizing roll can be greater than 150m / s (for example, 170m / s), so that the strip can be fully cooled,...

example 2

[0055] Example 2, the thickness of the strip to be cooled is 1.5mm. When the high-temperature strip steel after soaking and slow cooling enters the patented combined cooling zone of high-hydrogen high-speed jet cooling and roll cooling through the pinch rolls, the wrap angles of the strip steel and each water-cooled stabilizing roll are basically the same, and the insertion of the water-cooled rolls is controlled The depth stabilizes the wrapping angle θ at about 70°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 80% at a high speed at a flow rate of 160m / s to the surface of the running high-temperature strip to rapidly cool the strip. The ultra-high-speed and large-flow back-blowing airflow velocity of 190m / s at the wrap angle of the water-cooled stabilizing roll greatly improves the average cooling rate of the strip. Because the strip steel is relatively thick, a lower strip speed V=180mpm=3m / s is adopted. At this t...

example 3

[0057] Example 3, the strip thickness to be cooled is 1.2mm. When the high-temperature strip steel after soaking and slow cooling enters the patented combined cooling zone of high-hydrogen high-speed jet cooling and roll cooling through the pinch rolls, the wrap angles of the strip steel and each water-cooled stabilizing roll are basically the same, and the insertion of the water-cooled rolls is controlled The depth stabilizes the wrapping angle θ at about 65°. At the same time, the high-hydrogen nozzle sprays a protective gas with a hydrogen concentration of about 75% at a high speed at a flow rate of 150m / s to the surface of the running high-temperature strip to rapidly cool the strip, and set it on the strip The ultra-high-speed and large-flow back-blowing airflow at the wrap angle of the water-cooled stabilizing roll is 180m / s. At this time, the medium belt speed V=240mpm=4m / s is adopted. At this time, the three-stage high hydrogen jet cooling section, roll cooling and bac...

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