阅读说明：本技术 一种镀铝锌半硬质钢炉内跑偏及入锌炉温度控制的方法 (Method for controlling deviation in aluminum-zinc-plated semi-hard steel furnace and temperature in zinc furnace ) 是由 宋利伟 王植 刘军友 刘小辉 孙荣生 李岩 蔡顺达 金晓龙 庞旭 姜丽丽 于 2021-06-28 设计创作，主要内容包括：本发明的目的在于提供一种镀铝锌半硬质钢炉内跑偏及入锌炉温度控制的方法,为确保带钢在炉内跑偏及入锌锅温度精确受控,从两个方面进行优化方案设计。其一,是通过研究炉内各段炉膛区域温度、炉区张力、纠偏装置的控制等手段,降低带钢横向受力及张力波动等原因造成的跑偏趋势,从而可以减少半硬质高强钢生产时的跑偏风险；其二,是通过研究带钢成分、退火速度,炉内各段炉膛区域温度、快冷段电感应加热器功率的优化等方面,可以尽最大程度提高带钢再结晶温度、减少快冷风机对带钢的冷却降温影响,从而实现对带钢入锌锅温度的精确控制,保证成品性能稳定性。(The invention aims to provide a method for controlling the deviation of a galvanized semi-hard steel in a furnace and the temperature of the steel entering the zinc furnace, which is designed by an optimization scheme from two aspects in order to ensure that the steel strip is accurately controlled in the deviation of the steel in the furnace and the temperature of the steel entering a zinc pot. Firstly, the deviation tendency caused by the reasons of transverse stress, tension fluctuation and the like of strip steel is reduced by means of researching the temperature of each section of hearth area in the furnace, the tension of the furnace area, the control of a deviation correcting device and the like, so that the deviation risk in the production of semi-hard high-strength steel can be reduced; and secondly, by researching the aspects of the components of the strip steel, the annealing speed, the temperature of each hearth region in the furnace, the optimization of the power of the electric induction heater at the fast cooling section and the like, the recrystallization temperature of the strip steel can be improved to the greatest extent, and the influence of a fast cooling fan on the cooling of the strip steel is reduced, so that the accurate control of the temperature of the strip steel entering a zinc pot is realized, and the performance stability of a finished product is ensured.)

1. A method for controlling the deviation in an aluminum-zinc-plated semi-hard steel furnace and the temperature of the aluminum-zinc-plated semi-hard steel furnace is characterized by comprising the following steps:

1) controlling the temperature of the continuous annealing furnace: the temperature control range of the heating 1-section zone of the continuous annealing furnace is 840-860 ℃; the temperature control range of the heating 2-section zone of the continuous annealing furnace is 765-780 ℃; the temperature control range of the heating 3-section zone of the continuous annealing furnace is 760-780 ℃;

2) establishing a dynamic adjusting mechanism for linking the tension in the continuous annealing furnace with the display value of the deviation correcting device in the fast cooling area of the continuous annealing furnace: the actual tension value of the fast cooling section and the displayed value of the deviation correcting device are automatically controlled in a linkage manner, and when the displayed value of the deviation correcting device is between-3 mm and +3mm, the tension value of the fast cooling section executes the numerical value in the secondary database; when the display value of the deviation correcting device exceeds-3 mm or +3mm, the tension value of the fast cooling section is automatically increased by 30 percent on the basis of the numerical value of the secondary database;

the tension of other sections in the continuous annealing furnace is synchronously increased by 5 to 10 percent;

3) controlling the speed of the strip steel: the process speed of the strip steel with the thickness of 0.6-2.00mm is not lower than 68m/min, and the speed range is 68-150 m/min.

2. The method for controlling the deviation and the temperature of the strip steel entering the zinc plating furnace in the aluminum-zinc-plated semi-hard steel furnace as claimed in claim 1, wherein in the heating 2 section of the continuous annealing furnace, if the temperature of the strip steel plate is within the furnace temperature control range, the hydrogen is ensured to be stopped in the heating 2 section of the continuous annealing furnace, and the hydrogen flow is 40-50m³H; if the plate temperature exceeds the furnace temperature control range, the adjustment of the closed zone is carried out, but the furnace temperature of at least 2 zones is ensured to be normal, and at the moment, the hydrogen is automatically stopped.

3. The method for controlling the deviation and the temperature of the steel strip entering the zinc plating furnace in the aluminum-zinc plated semi-hard steel furnace according to the claim 1, wherein in the heating section 3 of the continuous annealing furnace, when the thickness of the steel strip is less than 1.0mm, a first zone and a third zone are closed, and a second zone and a fourth zone are used for heating; when the thickness of the strip steel is more than 1.0mm, the four areas are heated together.

4. The method for controlling the deviation and the temperature of the steel strip entering the zinc plating furnace in the aluminum-zinc plated semi-hard steel furnace according to the claim 1, wherein the steel strip speed in the step 3) is controlled as follows: the process speed of the strip steel with the thickness of 0.6-0.8mm is not lower than 135m/min, and the speed range is 135-150 m/min; the process speed of the strip steel with the thickness of 0.81-1.1mm is not lower than 120m/min, and the speed range is 120-135 m/min; the process speed of the strip steel with the thickness of 1.11-1.5mm is not lower than 105m/min, and the speed range is 105-120 m/min; the process speed of the strip steel with the thickness of 1.5-1.8mm is not lower than 75m/min, and the speed range is 75-85 m/min; the process speed of the strip steel with the thickness of 1.81-2.00mm is not lower than 68m/min, and the speed range is 68-78 m/min.

5. The method for controlling the deviation in the aluminum-zinc-plated semi-hard steel furnace and the temperature of the aluminum-zinc-plated semi-hard steel entering the zinc furnace according to claim 1, wherein the aluminum-zinc-plated semi-hard steel comprises the following chemical components in percentage by weight: 0.050 to 0.080 percent of C, less than or equal to 0.040 percent of Si, 0.20 to 0.40 percent of Mn0.20 percent, less than or equal to 0.20 percent of Ni, less than or equal to 0.20 percent of Cr, less than or equal to 0.06 percent of Mo, less than or equal to 0.20 percent of Cu, 0.02 to 0.030 percent of Nb, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, less than or equal to 0.008 percent of N, 0.010 to 0.050 percent of Als0.008 percent, less than or equal to 0.008 percent of V, less than or equal to 0.008 percent of Ti, and the balance of Fe and inevitable impurities.

Technical Field

The invention relates to the field of cold rolling, in particular to a method for controlling the deviation in an aluminum-zinc-plated semi-hard steel furnace and the temperature of the aluminum-zinc-plated semi-hard steel furnace.

Background

The S550GD aluminum-zinc-plated steel strip is a low-cost high-added-value product, and the domestic market demand is increased rapidly with the technical progress of domestic cold-formed steel. The semi-hard high-strength steel aluminized zinc product S550GD only has a few steel enterprises, and enterprises capable of stably producing 0.6-2.0mm products are very limited. After an aluminum-zinc plating continuous annealing furnace of a certain steel mill is upgraded and transformed in 2019 years, a section of radiant tube heating section is newly added, and the capacity of 8 spray cooling fans is increased, so that the heating and cooling conditions in the furnace and the detection position of the temperature of strip steel are greatly changed, for S550GD product which is very sensitive to the heating temperature, the furnace area temperature and the temperature of strip steel entering a zinc pot in the production process of the strip steel must be accurately controlled, so as to be expected to reach the performance of finished products meeting the standard requirements, at present, the aluminum-zinc plating machine set adopts a vertical continuous annealing furnace, and meanwhile, according to understanding, most of domestic large-scale steel mills also adopt a vertical continuous annealing furnace for producing aluminum-zinc plated products, the furnace type for producing semi-high-strength aluminum-zinc plated products has the defects that the furnace is too high, the furnace is influenced by the factors such as high yield strength of the semi-hard high-strength products, unstable plate shape and the like, and the risk of strip steel deflection and breakage in the furnace is high, and the length of the cooling section in the furnace is too large, so that the temperature of the strip steel entering a zinc pot is easy to be too low, and the risk of the unsuitable performance of the finished product exists. At present, the dynamic regulation and control technology for the furnace roller convexity of the continuous annealing furnace in part of steel mills is known, so that the function of matching the furnace roller convexity with strip steel can be realized by regulating the heating or cooling of the furnace roller body at any time, and the risk of the in-furnace deviation of semi-hard high-strength steel products is reduced. The continuous annealing furnace roller of the aluminum-zinc plating unit does not have the function, so that the convexity of the furnace roller can be controlled only by controlling the temperature of an area and the like, and the risk of deviation in the furnace is reduced by controlling the tension. Simultaneously, according to understanding, the electric induction heating body of part steel mill with the cooling zone is installed and is close zinc pot entrance in the stove district, the temperature that causes when can evading the quick cold section cooling blower of induction heating back belted steel rethread like this descends by a wide margin, thereby can improve belted steel and go into the accuracy of zinc pot temperature, and this aluminize zinc unit receives the restriction of stove district structure, the inductor can only be installed in quick cold section top, belted steel will continue to reach zinc pot entrance through quick-cooling fan after induction heating, consequently, be unfavorable for belted steel to go into the accurate control of zinc pot temperature.

Therefore, in order to open the market share of semi-hard high-strength aluminum and zinc plated products and stably produce the semi-hard high-strength aluminum and zinc plated products by using the existing furnace type, the technological parameters of the production process of the semi-hard high-strength aluminum and zinc plated products need to be specially debugged and optimized, the stable quality of the semi-hard high-strength aluminum and zinc plated products is ensured, the requirements of customers are met, and the blank of product varieties is filled.

Disclosure of Invention

The invention aims to provide a method for controlling the deviation in an aluminum-zinc-plated semi-hard steel furnace and the temperature of the aluminum-zinc-plated semi-hard steel furnace, which utilizes the existing annealing furnace to balance the influence of heating and cooling on the premise of not increasing the equipment investment, inhibits the deviation in the furnace, realizes the stable production of semi-hard high-strength aluminum-zinc-plated layer products, ensures the accurate temperature of the steel strip in a zinc pot, and ensures the stable operation of a unit and the conformity of product performance, plate shape and surface quality.

In order to achieve the purpose, the invention adopts the following technical scheme:

a method for controlling the deviation and the temperature of the aluminum-zinc-plated semi-hard steel in a zinc furnace specifically comprises the following steps:

1) controlling the temperature of the continuous annealing furnace: the temperature control range of the heating 1-section zone of the continuous annealing furnace is 840-860 ℃; the temperature control range of the heating 2-section zone of the continuous annealing furnace is 765-780 ℃; the temperature control range of the heating 3-section zone of the continuous annealing furnace is 760-780 ℃;

2) establishing a dynamic adjusting mechanism for linking the tension in the continuous annealing furnace with the display value of the deviation correcting device in the fast cooling area of the continuous annealing furnace: the actual tension value of the fast cooling section and the displayed value of the deviation correcting device are automatically controlled in a linkage manner, and when the displayed value of the deviation correcting device is between-3 mm and +3mm, the tension value of the fast cooling section executes the numerical value in the secondary database; when the display value of the deviation correcting device exceeds-3 mm or +3mm, the tension value of the fast cooling section is automatically increased by 30 percent on the basis of the numerical value of the secondary database;

the tension of other sections in the continuous annealing furnace is synchronously increased by 5 to 10 percent;

3) controlling the speed of the strip steel: the process speed of the strip steel with the thickness of 0.6-2.00mm is not lower than 68m/min, and the speed range is 68-150 m/min.

In the heating 2 section of the continuous annealing furnace, if the temperature of the strip steel plate is in the furnace temperature control range, the continuous annealing furnace is ensured to heat 2 sections of hydrogen without stopping, and the hydrogen flow is 40-50m³H; if the plate temperature exceeds the furnace temperature control range, the adjustment of the closed zone is carried out, but the furnace temperature of at least 2 zones is ensured to be normal, and at the moment, the hydrogen is automatically stopped.

In the heating section 3 of the continuous annealing furnace, when the thickness of the strip steel is less than 1.0mm, closing the first zone and the third zone, and heating by using the second zone and the fourth zone; when the thickness of the strip steel is more than 1.0mm, the four areas are heated together.

The steel strip speed in the step 3) is controlled as follows: the process speed of the strip steel with the thickness of 0.6-0.8mm is not lower than 135m/min, and the speed range is 135-150 m/min; the process speed of the strip steel with the thickness of 0.81-1.1mm is not lower than 120m/min, and the speed range is 120-135 m/min; the process speed of the strip steel with the thickness of 1.11-1.5mm is not lower than 105m/min, and the speed range is 105-120 m/min; the process speed of the strip steel with the thickness of 1.5-1.8mm is not lower than 75m/min, and the speed range is 75-85 m/min; the process speed of the strip steel with the thickness of 1.81-2.00mm is not lower than 68m/min, and the speed range is 68-78 m/min.

The aluminum-zinc plated semi-hard steel comprises the following chemical components in percentage by weight: 0.050 to 0.080 percent of C, less than or equal to 0.040 percent of Si, 0.20 to 0.40 percent of Mn0.20 percent, less than or equal to 0.20 percent of Ni, less than or equal to 0.20 percent of Cr, less than or equal to 0.06 percent of Mo, less than or equal to 0.20 percent of Cu, 0.02 to 0.030 percent of Nb, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, less than or equal to 0.008 percent of N, 0.010 to 0.050 percent of Als0.008 percent, less than or equal to 0.008 percent of V, less than or equal to 0.008 percent of Ti, and the balance of Fe and inevitable impurities.

Compared with the prior art, the invention has the beneficial effects that:

before the method is used, the deviation in the aluminum-zinc-plated semi-hard high-strength steel furnace is 20mm at most, the unqualified frequency is 1.56 percent, and the unqualified product rate is 1.52 percent due to the unqualified temperature in a zinc pot;

after the method is used, the deviation in the aluminum-zinc-plated semi-hard high-strength steel furnace is 5mm at most, the unqualified frequency caused by the deviation is 0%, and the unqualified product rate caused by the unqualified temperature of the zinc pot is 0.31%.

Detailed Description

The present invention is described in more detail by way of examples, which are merely illustrative of the best mode of carrying out the invention and are not intended to limit the scope of the invention in any way.

The invention is designed in an optimization scheme from two aspects in order to ensure that the strip steel deviates in the furnace and the temperature of the strip steel entering the zinc pot is accurately controlled. Firstly, the deviation tendency caused by the reasons of transverse stress, tension fluctuation and the like of strip steel is reduced by means of researching the temperature of each section of hearth area in the furnace, the tension of the furnace area, the control of a deviation correcting device and the like, so that the deviation risk in the production of semi-hard high-strength steel can be reduced; and secondly, by researching the aspects of the components of the strip steel, the annealing speed, the temperature of each hearth region in the furnace, the optimization of the power of the electric induction heater at the fast cooling section and the like, the recrystallization temperature of the strip steel can be improved to the greatest extent, and the influence of a fast cooling fan on the cooling of the strip steel is reduced, so that the accurate control of the temperature of the strip steel entering a zinc pot is realized, and the performance stability of a finished product is ensured.

A method for controlling the deviation and the temperature of the aluminum-zinc-plated semi-hard steel in a zinc furnace specifically comprises the following steps:

1) the temperature control scheme of each section of the furnace zone is optimized, and the temperature difference of the zones is reduced, so that the temperature difference of the roll surface in the running direction of the strip steel can be reduced, and the temperature gradient difference in the width range of each furnace roll can be reduced. Controlling the temperature of the continuous annealing furnace: the control range of the zone temperature of the continuous annealing furnace at the heating 1 section is 840-860 ℃, and the target value of the zone temperature is 845 ℃; the temperature control range of the heating section 2 of the continuous annealing furnace is 765-780 ℃, the target temperature of the heating section is 765 ℃, the temperature control range of the heating section 3 of the continuous annealing furnace is 760-780 ℃, and the target temperature of the heating section is 760 ℃;

2) before producing semi-hard products, checking and confirming the deviation correcting device in the furnace, avoiding deviation correcting position difference, establishing a dynamic adjusting mechanism for linking the tension in the furnace and the display value of the deviation correcting device in the continuous annealing furnace fast cooling area (namely, the actual value of the tension of the fast cooling section and the display value of the deviation correcting device are automatically linked and controlled, and when the display value of the deviation correcting device is between-3 mm and +3mm, the tension value of the fast cooling section executes the numerical value in a secondary database; when the display value of the deviation correcting device exceeds-3 mm or +3mm, the tension value of the fast cooling section is automatically increased by 30 percent on the basis of the numerical value of the secondary database, and timely intervention is performed to avoid the aggravation of deviation; all other tension in the continuous annealing furnace is in a manual control mode, the tension of each section is synchronously increased by 5-10%, the actual tension value is stabilized, and deviation caused by frequent fluctuation of the tension is avoided;

3) controlling the speed of the strip steel: the process speed of the strip steel with the thickness of 0.6-2.00mm is not lower than 68m/min, and the speed range is 68-150 m/min.

4) Putting the electric induction heater in a fast cooling section, wherein the output of the electric induction heater is more than 20% (the larger the output is, the better the output is), the plate temperature of the strip steel in the zinc pot is ensured to reach more than 575 ℃, and the plate temperature control range is 575-;

5) properly adjusting the steel composition, and changing Ti strengthening into Nb strengthening. Adjusting the Nb content in the steel composition to be 0.02 wt% -0.03 wt%, and Ti is less than or equal to 0.008 wt%.

In the heating 2 section of the continuous annealing furnace, if the temperature of the strip steel plate is in the furnace temperature control range, the hydrogen is ensured to be not stopped in the heating 2 section of the continuous annealing furnace, and the hydrogen flow is 40-50m³H; and if the plate temperature exceeds the furnace temperature control range, closing the zone, but at least ensuring that the furnace temperature of 2 zones is normal, and automatically stopping hydrogen at the moment to pay attention to the adhesive force detection result of the tail zinc layer.

In the heating section 3 of the continuous annealing furnace, when the thickness of the strip steel is less than 1.0mm, closing the first zone and the third zone, and heating by using the second zone and the fourth zone; when the thickness of the strip steel is more than 1.0mm, the four areas are heated together.

The steel strip speed in the step 3) is controlled as follows: the process speed of the strip steel with the thickness of 0.6-0.8mm is not lower than 135m/min, and the speed range is 135-150 m/min; the process speed of the strip steel with the thickness of 0.81-1.1mm is not lower than 120m/min, and the speed range is 120-135 m/min; the process speed of the strip steel with the thickness of 1.11-1.5mm is not lower than 105m/min, and the speed range is 105-120 m/min; the process speed of the strip steel with the thickness of 1.5-1.8mm is not lower than 75m/min, and the speed range is 75-85 m/min; the process speed of the strip steel with the thickness of 1.81-2.00mm is not lower than 68m/min, and the speed range is 68-78 m/min.

The aluminum-zinc plated semi-hard steel comprises the following chemical components in percentage by weight: 0.050 to 0.080 percent of C, less than or equal to 0.040 percent of Si, 0.20 to 0.40 percent of Mn0.20 percent, less than or equal to 0.20 percent of Ni, less than or equal to 0.20 percent of Cr, less than or equal to 0.06 percent of Mo, less than or equal to 0.20 percent of Cu, 0.02 to 0.030 percent of Nb, less than or equal to 0.02 percent of P, less than or equal to 0.02 percent of S, less than or equal to 0.008 percent of N, 0.010 to 0.050 percent of Als0.008 percent, less than or equal to 0.008 percent of V, less than or equal to 0.008 percent of Ti, and the balance of Fe and inevitable impurities.

Examples steel grades: s550GD, steel code: ABVA21, steel grade composition is shown in Table 1.

Table 1: examples 1-5 steel strip steel grade chemical composition (wt%)

C

Si

Mn

P

S

AlS

N

Ni

Cr

Cu

Nb

V

Ti

Mo

0.065

0.010

0.30

-

-

0.030

≤0.0080

≤0.20

≤0.20

≤0.20

0.025

≤0.008

≤0.008

≤0.06

The process parameters of the examples are shown in Table 2.

Table 2: EXAMPLES 1-5 Process parameters