阅读说明：本技术 一种无底渣生产合金化热镀锌ga产品的方法 (Method for producing alloyed hot-dip galvanized GA product without bottom slag ) 是由 张理扬 王骏飞 孟宪陆 于 2021-08-30 设计创作，主要内容包括：本发明涉及带钢连续热镀锌技术领域,且公开了一种无底渣生产合金化热镀锌GA产品的方法,包括以下内容：先对带钢进行清洗,然后进行基板退火处理,接着浸入锌锅的锌液中进行热浸镀,在进行热浸镀的时候,将锌液的有效铝含量控制在0.135%-0.145%之间,再经气刀控制镀层重量后进入镀层合金化退火段进行镀层合金化退火处理,然后进行水冷、平整等后处理,生产出镀层铁含量大于等于7%的合金化热镀锌GA产品,最终实现无底渣生产合金化热镀锌GA产品；本发明可以大幅度的降低GA产品的生产成本,极大的提升产品竞争力,可以在新建机组或者对原有机组进行适应性改造后推广应用,且非常具有推广应用前景。(The invention relates to the technical field of strip steel continuous hot galvanizing, and discloses a method for producing an alloying hot galvanizing GA product without bottom slag, which comprises the following steps: firstly cleaning strip steel, then carrying out substrate annealing treatment, then immersing the strip steel into zinc liquid in a zinc pot for hot dip coating, controlling the effective aluminum content of the zinc liquid to be 0.135-0.145% during the hot dip coating, then controlling the coating weight by an air knife, then entering a coating alloying annealing section for coating alloying annealing treatment, then carrying out post-treatment such as water cooling, leveling and the like, producing an alloying hot dip galvanized GA product with the coating iron content being more than or equal to 7%, and finally realizing the production of the alloying hot dip galvanized GA product without bottom slag; the invention can greatly reduce the production cost of GA products, greatly improve the product competitiveness, can be popularized and applied after newly building a unit or adaptively transforming the original unit, and has popularization and application prospects.)

1. A method for producing an alloying hot galvanizing GA product without bottom slag is characterized in that: the method comprises the following steps: firstly cleaning strip steel, then carrying out substrate annealing treatment, then immersing the strip steel into zinc liquid in a zinc pot for hot dip coating, controlling the effective aluminum content of the zinc liquid to be 0.135-0.145% during the hot dip coating, then controlling the coating weight by an air knife, entering a coating alloying annealing section for coating alloying annealing treatment, then carrying out post-treatment such as water cooling and leveling, and producing an alloying hot dip galvanizing GA product with the coating iron content being more than or equal to 7%, and finally realizing the production of the alloying hot dip galvanizing GA product without bottom slag.

2. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 1, which is characterized in that: the annealing treatment of the substrate adopts a method of direct fire heating and radiant tube heating to heat and soak strip steel, the direct fire heating adopts a pre-oxidation process, the radiant tube heating and soaking section adopts a reduction process to carry out pre-oxidation reduction treatment on the strip steel, a layer of reduced iron is generated on the surface of the substrate, and then hot dip coating and coating alloy annealing treatment are carried out.

3. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 2, which is characterized in that: the air excess coefficient of the direct-fire heating direct-fire combustion is controlled to be 0.93-0.97, and the fuel of the direct-fire heating combustion is artificial natural gas or conventionally mined natural gas or liquefied petroleum gas.

4. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 3, characterized by comprising the following steps: and during the annealing treatment of the substrate, the dew points of the heating section and the soaking section of the radiant tube are controlled between-40 ℃ and 0 ℃, so that the enrichment of elements such as silicon, manganese and the like to the surface of the substrate is further inhibited.

5. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 1, which is characterized in that: and during the hot dip plating, the temperature of the zinc liquid is controlled between 460 and 475 ℃.

6. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 1, which is characterized in that: before the hot dipping, the temperature of the strip steel in the zinc pot is accurately controlled, and the temperature of the strip steel in the zinc pot is controlled between 460 and 515 ℃ and is more than or equal to the temperature of zinc liquid.

7. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 1, which is characterized in that: the above-mentionedControlling the weight of the coating by an air knife, and controlling the weight of one side of the coating to be 30-72g/m²Further preferably in the range of 30 to 60g/m²In the meantime.

8. The method for producing the alloyed hot-dip galvanized GA product without the slag according to claim 1, which is characterized in that: the coating alloying annealing treatment is carried out by heating the coating by adopting a method combining electromagnetic induction heating and direct fire heating, heating the coating by adopting a method combining direct fire combustion waste gas and electric radiant tubes, and cooling the coating by adopting a method combining aerial fog cooling and high-speed air injection cooling.

Technical Field

The invention relates to the technical field of strip steel continuous hot galvanizing, in particular to a method for producing an alloying hot galvanizing GA product without bottom slag.

Background

In order to improve the corrosion resistance of the strip steel, the strip steel can be subjected to hot galvanizing treatment. Hot galvanizing has a plurality of coating products, but in the field of automobile plates, the coating products with the largest hot galvanizing use amount mainly have three types: hot-dip pure zinc coating products (hereinafter referred to as GI coating products), alloyed hot-dip galvanized coating products (hereinafter referred to as GA coating products) and hot-dip low-aluminum zinc aluminum magnesium coating products (hereinafter referred to as ZAM coating products). Among them, GA coating products are commonly used in the japanese automobiles due to their advantages of excellent corrosion resistance, weldability, paintability, stone-strike resistance, manufacturability, zinc resource saving, etc. The production method of the traditional GA coating product comprises the steps of cleaning a strip steel 11 in a cleaning section 12, then entering a substrate annealing treatment section 13 for substrate annealing treatment, then immersing the strip steel into a zinc liquid in a zinc pot 15 from a furnace nose 14 for hot galvanizing, controlling the coating weight by an air knife 16, then entering an alloying heating section 17, an alloying soaking section 18 and an alloying cooling section 19 for coating alloying annealing treatment (GA treatment for short), then carrying out air jet cooling by a common air jet cooling section 20, then carrying out water cooling by a final water cooling section 21, and finally carrying out post-treatment such as leveling 22 to produce the GA coating product (shown in figure 1). When a strip steel is immersed in zinc liquid in a zinc pot for hot galvanizing, the effective aluminum content of the zinc liquid (namely the total aluminum content in the zinc liquid-the iron content in the zinc liquid) is usually controlled to be below 0.135 percent, a GA coating product is produced by a traditional method, zinc slag is gradually deposited at the bottom of the zinc liquid in the zinc pot, and after the production is carried out for a certain time (usually about 20 days), two treatment methods are usually adopted. Firstly, stopping the machine to carry out bottom slag fishing operation, fishing out the bottom slag, and then carrying out GA coating product production. For example, patent CN200510024112.1 discloses a zinc pot bottom slag cleaning device for improving the zinc pot bottom slag cleaning efficiency. Secondly, adding high-aluminum zinc ingots into a zinc pot, increasing the total aluminum content of zinc liquid to more than 0.15 percent, usually to about 0.20 percent, and producing GI coating products, wherein during the process of increasing the aluminum content of the zinc liquid and the production of the GI coating products, bottom slag in the zinc pot is gradually changed into suspended dross and dross which are taken away by the coating or removed from the zinc pot. The first method has long treatment time, GA cannot be continuously produced, and the loss of zinc liquid caused by removing zinc slag is large, so that the production cost is high. In the second method, only products with relatively low surface quality requirements, such as color-coated substrates, building panels, etc., can be produced during switching, and a color-coated unit needs to be constructed in a matching manner or low-profit products need to be produced, which is not favorable for improving enterprise competitiveness. Patent CN200710148463.2 discloses a zinc plating solution for use in a slag-free hot galvanizing production process, which contains 0.151-0.179% of aluminum and some elements such as lead and antimony, which are harmful elements and obviously unsuitable for GA production. While the patent US6177140(B1) shows a method for simultaneously producing GI and GA products, which requires controlling the temperature of the molten zinc at 440-450 ℃, obviously, the temperature control range of the molten zinc is not favorable for the alloying annealing of the coating. No matter the machine is stopped to drag for the bottom slag, or the zinc liquid aluminum content is switched to be improved to produce GI products, the long-term stable production of the GA products is not facilitated, and the production cost of the GA products is invisibly increased.

Disclosure of Invention

Technical problem to be solved

Aiming at the defects of the prior art, the invention provides a method for producing an alloying hot dip galvanizing GA product without bottom slag, which solves the problems in the background technology.

(II) technical scheme

In order to achieve the purpose, the invention provides the following technical scheme: a method for producing an alloyed hot-dip galvanized GA product without bottom slag comprises the following steps: firstly cleaning strip steel, then carrying out substrate annealing treatment, then immersing the strip steel into zinc liquid in a zinc pot for hot dip coating, controlling the effective aluminum content of the zinc liquid to be 0.135-0.145% during the hot dip coating, then controlling the coating weight by an air knife, entering a coating alloying annealing section for coating alloying annealing treatment, then carrying out post-treatment such as water cooling and leveling, and producing an alloying hot dip galvanizing GA product with the coating iron content being more than or equal to 7%, and finally realizing the production of the alloying hot dip galvanizing GA product without bottom slag.

Preferably, the substrate annealing treatment adopts a direct fire heating and radiant tube heating method to heat and soak the strip steel, the direct fire heating adopts a pre-oxidation process, the radiant tube heating and soaking section adopts a reduction process to carry out pre-oxidation reduction treatment on the strip steel, a layer of reduced iron is generated on the surface of the substrate, and then hot dip plating and plating alloy annealing treatment are carried out.

Preferably, the air surplus coefficient of the direct-fire heating direct-fire combustion is controlled to be 0.93-0.97, and the fuel of the direct-fire heating combustion is artificial natural gas or conventionally-mined natural gas or liquefied petroleum gas.

Preferably, during the annealing treatment of the substrate, the dew points of the heating section and the soaking section of the radiant tube are controlled between-40 ℃ and 0 ℃, and the enrichment of elements such as silicon, manganese and the like to the surface of the substrate is further inhibited.

Preferably, the temperature of the zinc liquid is controlled between 460 and 475 ℃ during the hot dip plating.

Preferably, before the hot dip coating, the temperature of the strip steel entering the zinc pot is accurately controlled, and the temperature of the strip steel entering the zinc pot is controlled to be between 460 and 515 ℃ and is more than or equal to the temperature of zinc liquid.

Preferably, the weight of the coating is controlled by the air knife, and the weight of one side of the coating is controlled to be 30-72g/m²Further, furtherPreferably controlled at 30-60g/m²In the meantime.

Preferably, the alloying annealing treatment of the coating is carried out by heating the coating by adopting a method combining electromagnetic induction heating and direct fire heating or a method combining direct fire combustion waste gas and electric radiant tube heating or cooling the coating by adopting a method combining aerosol cooling and high-speed jet cooling.

(III) advantageous effects

The invention provides a method for producing an alloying hot-dip galvanizing GA product without bottom slag, which has the following beneficial effects:

the invention can greatly increase the production cost of the alkalinity GA product, greatly improve the product competitiveness, can be popularized and applied after newly building a unit or adaptively transforming the original unit, and has popularization and application prospects.

Drawings

FIG. 1 is a schematic view of a conventional method for producing a galvannealed product;

FIG. 2 is a schematic diagram of the method for producing the galvannealed product according to the present invention.

In the figure: 11. strip steel; 12. a cleaning section; 13. a substrate annealing treatment section; 14. a furnace nose; 15. a zinc pot; 16. an air knife; 17. an alloying heating section; 18. an alloying soaking section; 19. an alloying cooling section; 20. a common air injection cooling section; 21. a final water cooling section; 22. leveling section; 23. a direct-fired combustion exhaust gas preheating section; 24. a direct fire heating section; 25. a radiant tube heating section; 26. a radiant tube soaking section; 27. a slow cooling section; 28. a rapid cooling section; 29. and (6) equalizing the section.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

The base plate is characterized in that a strip steel 11 with the main components of 0.0012% of C, 0.0015% of Si, 0.12% of Mn, 0.006% of P and 0.002% of S in percentage by mass is firstly cleaned in a cleaning section 12, specifically comprises alkali spraying, alkali brushing, electrolytic cleaning, hot water brushing, hot water rinsing and drying, and then enters 3% of H₂And 97% N₂The protective atmosphere annealing furnace carries out substrate annealing treatment, wherein the substrate annealing treatment comprises the steps of entering a direct-fired combustion waste gas preheating section 23 for preheating direct-fired waste gas, then entering a direct-fired heating section 24 for heating direct fire, then entering a radiant tube heating section 25 for heating radiant tubes, then entering a radiant tube soaking section 26 for soaking radiant tubes, then entering a slow cooling section 27 for slow cooling, then entering a fast cooling section 28 for fast cooling, finally entering an equalizing section 29 for equalizing treatment, and then carrying out hot dip coating; when the direct fire heating is carried out, natural gas naturally mined is adopted, the excess coefficient of direct fire combustion air is controlled to be 0.93, the band steel 11 is heated to 680 ℃, then enters a heating section 25 of a radiant tube, is continuously heated to 830 ℃, then enters a soaking section 26 of the radiant tube, is subjected to soaking treatment for 40s at 830 ℃, then enters a slow cooling section 27 to be slowly cooled to 670 ℃, then enters a fast cooling section 28 to be quickly cooled to 475 ℃, enters an equalizing section 29 to be equalized at 475 ℃, and is immersed into zinc liquid at 460 ℃ in a zinc pot 15 for hot dipping with the band steel 11 at 475 ℃; the dew points of the heating section 25 and the soaking section 26 of the radiant tube are controlled to be-40 ℃, and the dew points of the slow cooling section 27, the fast cooling section 28 and the equalizing section 29 are controlled to be below-45 ℃; in this embodiment, the effective aluminum content of the zinc liquid in the zinc pot 15 is controlled to be 0.145%; after the hot dip coating of the steel strip 11, the weight of the zinc layers on the upper and lower surfaces is controlled to 72/72g/m by the air knife 16²Then the strip steel is heated to 480 ℃ and then enters a combined heating alloying heating section 17 of electromagnetic induction heating and direct fire heating to carry out coating alloying annealing heating treatment, the strip steel 11 is heated to 480 ℃, then enters a combined soaking alloying soaking section 18 of direct fire combustion waste gas and electric radiant tube heating to carry out coating alloying annealing soaking treatment at about 480 ℃, then enters a combined cooling alloying cooling section 19 of aerial fog cooling and high-speed air injection cooling to carry out cooling, the strip steel is cooled to 300 ℃, then continuously enters a common air injection cooling section 20 and a final water cooling section 21 to carry out air injection cooling and final water cooling, and finally enters a leveling section 22 to enter a leveling section 22 to carry out air injection cooling and final water coolingCarrying out post-treatment such as leveling; in the embodiment, the content of the coated iron is basically controlled to be about 10.5 percent, the production is carried out for a long time, and no bottom slag is deposited in the zinc liquid of the zinc pot 15.

Compared with the traditional production method, the embodiment has the following differences:

compared with the traditional production method, the embodiment has the advantages that:

example 2

The base plate is characterized in that strip steel 11 with the main components of 0.08% of C, 0.40% of Si, 2.1% of Mn, 0.009% of P and 0.003% of S in percentage by mass is firstly cleaned in a cleaning section 12, specifically comprises alkali spraying, alkali brushing, electrolytic cleaning, hot water brushing, hot water rinsing and drying, and then enters 5% of H₂And 95% N₂The protective atmosphere annealing furnace carries out substrate annealing treatment, wherein the substrate annealing treatment comprises the steps of entering a direct-fired combustion waste gas preheating section 23 for preheating direct-fired waste gas, then entering a direct-fired heating section 24 for heating direct fire, then entering a radiant tube heating section 25 for heating radiant tubes, then entering a radiant tube soaking section 26 for soaking radiant tubes, then entering a slow cooling section 27 for slow cooling, then entering a fast cooling section 28 for fast cooling, finally entering an equalizing section 29 for equalizing treatment, and then carrying out hot dip coating; when heating by direct fire, liquefied petroleum gas is adopted, the surplus coefficient is controlled to be 0.95, the band steel 11 is heated to 650 ℃, then enters the radiant tube heating section 25, is continuously heated to 800 ℃, then enters the radiant tube soaking section 26, is soaked for 50s at 800 ℃, then enters the slow cooling section 27, is slowly cooled to 670 ℃, then enters the fast cooling section 28, is quickly cooled to 515 ℃, and enters the equilibriumThe section 29 is subjected to equalization treatment at 515 ℃, strip steel 11 at 515 ℃ is put into a zinc pot 15 and is immersed into zinc liquid at 470 ℃ for hot dip plating; the dew points of the heating section 25 and the soaking section 26 of the radiant tube are controlled to be below 20 ℃ below zero, and the dew points of the slow cooling section 27, the fast cooling section 28 and the equalizing section 29 are controlled to be below 45 ℃ below zero; in the embodiment, the effective aluminum content of the zinc liquid in the zinc pot 15 is controlled to be 0.140 percent; after the hot dip coating of the steel strip 11, the weight of the zinc layers on the upper and lower surfaces is controlled to 50/50g/m by the air knife 16²Then, the strip steel is heated to 500 ℃ and then enters a combined heating alloying heating section 17 of electromagnetic induction heating and direct fire heating to carry out coating alloying annealing heating treatment, the strip steel 11 is heated to 500 ℃, then enters a combined soaking alloying soaking section 18 of direct fire combustion waste gas and electric radiant tube heating to carry out coating alloying annealing soaking treatment at about 500 ℃, then enters a combined cooling alloying cooling section 19 of aerial fog cooling and high-speed air injection cooling to carry out cooling, the strip steel is cooled to 320 ℃, then continues to enter a common air injection cooling section 20 and a final water cooling section 21 to carry out air injection cooling and final water cooling, and finally enters a leveling section 22 to carry out post-treatment such as leveling; in the embodiment, the content of the coated iron is basically controlled to be about 11.5 percent, the production is carried out for a long time, and no bottom slag is deposited in the zinc liquid of the zinc pot 15.

Compared with the traditional production method, the embodiment has the following differences:

compared with the traditional production method, the embodiment has the advantages that:

example 3

The strip steel 11 with the main components of 0.18 percent of C, 1.8 percent of Si, 2.25 percent of Mn, 0.007 percent of P and 0.001 percent of S by mass percent is cleaned in a cleaning section 12, and concretely comprises alkali spraying, alkali brushing, electrolytic cleaning, hot water brushing, hot water rinsing and drying, and then the strip steel enters 7 percent of H₂And 93% N₂Protective atmosphere ofThe furnace carries out substrate annealing treatment, the substrate annealing treatment comprises the steps of entering a direct-fired combustion waste gas preheating section 23 for preheating direct-fired waste gas, then entering a direct-fired heating section 24 for heating direct fire, then entering a radiant tube heating section 25 for heating radiant tubes, then entering a radiant tube soaking section 26 for soaking radiant tubes, then entering a slow cooling section 27 for slow cooling, then entering a fast cooling section 28 for fast cooling, finally entering an equalizing section 29 for equalizing treatment, and then carrying out hot dip coating; adopting artificial natural gas during direct-fired heating, controlling the surplus coefficient to be 0.97, heating the strip steel 11 at 700 ℃, then entering the radiant tube heating section 25, continuing to heat to 850 ℃, then entering the radiant tube soaking section 26, carrying out soaking treatment at 850 ℃ for 60s, then entering the slow cooling section 27, slowly cooling to 675 ℃, then entering the fast cooling section 28, fast cooling to 500 ℃, entering the equalizing section 29, carrying out equalizing treatment at 500 ℃, and immersing the strip steel 11 at 500 ℃ into zinc liquid at 475 ℃ for hot dipping; the dew points of the heating section 25 and the soaking section 26 of the radiant tube are controlled to be 0 ℃, and the dew points of the slow cooling section 27, the fast cooling section 28 and the equalizing section 29 are controlled to be below 40 ℃ below zero; in the embodiment, the effective aluminum content of the zinc liquid in the zinc pot 15 is controlled to be 0.135%; after the hot dip coating of the steel strip 11, the weight of the zinc layers on the upper and lower surfaces is controlled to 30/30g/m by the air knife 16²Then, the strip steel is heated to 510 ℃ and then enters a combined heating alloying heating section 17 of electromagnetic induction heating and direct fire heating to carry out coating alloying annealing heating treatment, the strip steel is heated to 510 ℃, then enters a combined soaking alloying soaking section 18 of direct fire combustion waste gas and electric radiant tube heating to carry out coating alloying annealing soaking treatment at about 510 ℃, then enters a combined cooling alloying cooling section 19 of aerial fog cooling and high-speed air injection cooling to carry out cooling, the strip steel is cooled to 350 ℃, then continuously enters a common air injection cooling section 20 and a final water cooling section 21 to carry out air injection cooling and final water cooling, and finally enters a leveling section 22 to carry out post-treatment such as leveling; in the embodiment, the content of the coated iron is basically controlled to be about 11.0 percent, the long-time production is realized, no bottom slag is deposited in the zinc liquid of the zinc pot 15, and the long-time production of GA products by a unit is not influenced.

Compared with the traditional production method, the embodiment has the following differences:

compared with the traditional production method, the embodiment has the advantages that:

it is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.