CN111519016A - Preparation method of hot-galvanized sheet and hot-galvanized sheet - Google Patents
Preparation method of hot-galvanized sheet and hot-galvanized sheet Download PDFInfo
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- CN111519016A CN111519016A CN202010364411.4A CN202010364411A CN111519016A CN 111519016 A CN111519016 A CN 111519016A CN 202010364411 A CN202010364411 A CN 202010364411A CN 111519016 A CN111519016 A CN 111519016A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/52—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for wires; for strips ; for rods of unlimited length
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/26—Methods of annealing
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D11/00—Process control or regulation for heat treatments
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/04—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the coating material
- C23C2/06—Zinc or cadmium or alloys based thereon
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- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C2/00—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor
- C23C2/34—Hot-dipping or immersion processes for applying the coating material in the molten state without affecting the shape; Apparatus therefor characterised by the shape of the material to be treated
- C23C2/36—Elongated material
- C23C2/40—Plates; Strips
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Abstract
The invention discloses a preparation method of a hot-dip galvanized sheet and the hot-dip galvanized sheet. The preparation method comprises the following steps of preparing the cold-rolled strip steel into the hot-dip galvanized sheet through an annealing process and a hot-dip galvanizing process, wherein the preparation method comprises the following steps: inquiring a target annealing temperature T0 and a target strip steel running speed U0 of an annealing furnace used by the annealing process according to the parameters of the cold-rolled strip steel; controlling the running speed U of the strip steel of the annealing furnace to meet U0-Ub which is not less than U0+ Ua, and simultaneously controlling the annealing temperature T of the annealing furnace to meet T-T0, wherein Ua which is not less than 0m/min is not more than 10m/min, and Ub which is not less than 0m/min is not more than 10 m/min; and adjusting the running speed U of the strip steel, and regulating and controlling the annealing temperature T0-Ta when the running speed U of the strip steel is adjusted to be U which is more than or equal to U0-Uc and less than U0-Ub, wherein Uc is more than or equal to 10m/min and less than or equal to 20m/min, and Ta is more than or equal to 5 ℃ and less than or equal to 10 ℃. Compared with the prior art, the method has the advantages that the defect of mixed crystals caused by the speed reduction production of the annealing process section is eliminated, the deterioration of the mechanical property of the steel plate caused by the reduction of the annealing temperature is avoided, the method is simple and easy to implement, and the effect is obvious.
Description
Technical Field
The invention belongs to the technical field of hot-dip galvanized steel sheet production and manufacturing, and particularly relates to a hot-dip galvanized sheet preparation method and a hot-dip galvanized sheet prepared by the preparation method, in particular to a hot-dip galvanized sheet preparation method capable of reducing mixed crystal defects.
Background
The mixed crystal defect is a defect in which a part of grains having a significantly large size (also referred to as coarse grains) is present in the steel sheet structure, and the uniformity of the structure is deteriorated. For cold-rolled strip steel with mixed crystal defects, when a continuous hot galvanizing unit is further adopted to process hot galvanized plates through the procedures of cleaning, annealing, galvanizing, leveling, straightening, post-treatment and the like, quality problems such as plating bright spots, punched orange peel, cracking and the like are easily caused, the use of products is seriously influenced, and the requirements of high-end users cannot be met.
In general, the mixed crystal defect of cold rolled steel strip is generally considered to be caused by the inheritance of the mixed crystal defect of hot rolled raw material strip. Relevant research data show that in the production process of preparing hot-rolled raw material strip steel, the abnormal growth of crystal grains can be caused by factors such as low finish rolling temperature, high coiling temperature, compression deformation in the strip steel coiling process and the like.
Aiming at the problem of mixed crystal defects of cold-rolled strip steel, the current common practice is to improve the processing and preparation process of hot-rolled raw strip steel, for example, chinese patents with application numbers of 201210270620.8 and 201010602496.1, so as to eliminate the mixed crystal defects of the hot-rolled raw strip steel and further avoid the mixed crystal defects of cold-rolled steel sheets caused by heredity by improving the processing and preparation process of the hot-rolled raw strip steel.
However, in actual production, even if the texture of the hot-rolled raw strip steel does not have obvious mixed crystal defects, when the corresponding cold-rolled strip steel is further processed into a hot-galvanized sheet, the obtained hot-galvanized sheet still often has mixed crystal defects, and the mixed crystal defects are different from the surface mixed crystal defects caused by the inheritance of the hot-rolled raw strip steel, and are represented by the existence of part of grains with obvious and coarse sizes on the surface layer and the core part of the hot-galvanized sheet.
Through a great deal of research and study, the inventor finds that the mixed crystal defects are concentrated in the production process of preparing the hot-galvanized sheet by the cold-rolled strip steel, particularly when the annealing process section in the production process is subjected to speed reduction production, the running speed of the strip steel is reduced relative to the target running speed of the strip steel, and in other words, the running time in the annealing furnace is relatively prolonged.
However, in the actual production of hot-galvanized steel sheets from cold-rolled steel strips, the reduction of the production rate due to temporary equipment failure is inevitable, so that unqualified products with mixed crystal defects are extremely easy to generate in the production, the product yield is affected, and the cost is increased.
Disclosure of Invention
In order to solve the above technical problems, an object of the present invention is to provide a method for manufacturing a hot-dip galvanized sheet, and a hot-dip galvanized sheet manufactured by the manufacturing method.
In order to achieve the above objects, one embodiment provides a method for manufacturing a hot-galvanized sheet, in which a cold-rolled strip steel is manufactured into a hot-galvanized sheet through an annealing process and a hot-dip galvanizing process, the method comprising:
inquiring a target annealing temperature T0 and a target strip steel running speed U0 of an annealing furnace used by the annealing process according to the parameters of the cold-rolled strip steel;
controlling the running speed U of the strip steel of the annealing furnace to meet U0-Ub which is not less than U0+ Ua, and simultaneously controlling the annealing temperature T of the annealing furnace to meet T-T0, wherein Ua which is not less than 0m/min is not more than 10m/min, and Ub which is not less than 0m/min is not more than 10 m/min;
and adjusting the running speed U of the strip steel, and regulating and controlling the annealing temperature T0-Ta when the running speed U of the strip steel is adjusted to be U which is more than or equal to U0-Uc and less than U0-Ub, wherein Uc is more than or equal to 10m/min and less than or equal to 20m/min, and Ta is more than or equal to 5 ℃ and less than or equal to 10 ℃.
As a further improvement of an embodiment, when the "adjusting the strip steel running speed U":
when the running speed U of the strip steel is adjusted to be U (more than or equal to U) 0-Ud and U (less than U) 0-Uc, the annealing temperature T is adjusted to be T0-Tb, wherein Ud is more than or equal to 20m/min and less than or equal to 40m/min, Tb is more than or equal to 15 ℃ and less than or equal to 20 ℃;
when the running speed U of the strip steel is adjusted to be U (equal to or greater than U) 0-Ue and U (equal to or less than U0-Ud), the annealing temperature T is adjusted to be T0-Tc, wherein Ue is equal to or greater than 40m/min and equal to or less than 60m/min, and Tc is equal to or greater than 25 ℃ and equal to or less than 30 ℃.
As a further refinement of an embodiment, the parameters include specification and steel grade;
the cold-rolled strip steel is a cold-rolled low-carbon aluminum killed steel plate, the content of C is 0.010-0.040%, and the thickness is 0.4-1.6 mm.
As a further improvement of an embodiment, U0 takes a value within the range of 90 m/min-150 m/min, and T0 takes a value within the range of 815-855 ℃.
As a further development of an embodiment, Ua ═ Ub ═ 10m/min, Uc ═ 20m/min, Ub ═ 40m/min, Ue ═ 60 m/min;
Ta＝10℃，Tb＝20℃，Tc＝30℃。
as a further refinement of an embodiment, the method of making further comprises:
and acquiring abnormal information of current production, and executing the adjustment of the running speed U of the strip steel according to the abnormal information.
As a further improvement of an embodiment, the cold-rolled strip steel is prepared into the hot-dip galvanized sheet by adopting a continuous hot-dip galvanizing unit and sequentially performing a cleaning process, the annealing process, the hot-dip galvanizing process, a leveling and straightening process and a post-treatment process;
the continuous hot galvanizing unit comprises a cleaning device for implementing the cleaning process, the annealing furnace for implementing the annealing process, a hot-dip galvanizing kettle for implementing the hot-dip galvanizing process, leveling and straightening equipment for implementing the leveling and straightening process, and treatment equipment for implementing the post-treatment process.
As a further refinement of an embodiment, the abnormality information includes a failure of any of the hot-dip galvanizing kettle, the leveling and straightening device, and the treatment device.
In order to achieve the above objects, another embodiment provides a method for manufacturing a hot-galvanized sheet by performing an annealing process and a hot-dip galvanizing process on a cold-rolled strip steel to manufacture a hot-galvanized sheet, including:
inquiring a target annealing temperature T0 of an annealing furnace used by the annealing process and a target strip steel running speed U0 of the annealing furnace according to the parameters of the cold-rolled strip steel;
when the running speed U of the strip steel of the annealing furnace is adjusted to change from the state that U is not less than U0+ Ua and is not less than U0-Ub to the state that U is not less than U0-Ub, the annealing temperature T of the annealing furnace is synchronously regulated and controlled to change from the value T0 to the value T is less than T0, wherein Ua is not less than 0m/min and is not more than 10m/min, and Ub is not less than 0m/min and is not more than 10 m/min.
To achieve the above object, an embodiment further provides a hot-dip galvanized sheet, which is prepared by the preparation method according to any one of the previous embodiments.
Compared with the prior art, the invention has the beneficial effects that on one hand: aiming at the speed reduction production of the annealing process section of processing the cold-rolled strip steel into the hot-galvanized plate, the invention can effectively eliminate the mixed crystal defect of the hot-galvanized plate caused by the speed reduction production and ensure the texture grain uniformity of the obtained hot-galvanized plate.
With regard to the above beneficial effects, the detailed explanation thereof is specifically as follows:
in the annealing process section of processing the cold-rolled strip steel into the hot galvanized plate, according to the parameters of the cold-rolled strip steel, a series of process parameters such as the running speed (or duration parameter), the heating temperature, the annealing temperature, the cooling rate and the like of the strip steel are controlled by referring to the self annealing process table of the annealing furnace; for specific cold-rolled strip steel, a series of process parameters such as running speed (or duration parameter), heating temperature, annealing temperature, cooling rate and the like of strip steel in the production of an annealing process section are all target values determined by an annealing process table of the annealing furnace;
when the annealing process section needs to be produced at a reduced speed, for example, due to temporary equipment failure, the conventional common operation is to reduce the running speed of the strip steel relative to the target running speed of the annealing furnace, and the annealing temperature is still kept unchanged at the target annealing temperature of the annealing furnace;
thus, the running time of the cold-rolled strip steel in the annealing process section is increased, but the annealing temperature is kept at the target annealing temperature, the heating rate of the cold-rolled strip steel is relatively slowed down, so that the recrystallization nucleation rate in the structure is reduced, and part of grains with high energy storage preferentially nucleate, grow and continuously swallow newly nucleated small grains at the same time, so that part of grains grow abnormally, and finally mixed crystal defects are caused;
in view of the above exploration, in an embodiment of the present invention, when the annealing process is performed in the deceleration production, the annealing temperature is correspondingly controlled according to the adjustment degree of the band steel running speed, when the reduction of the band steel running speed is small, the annealing temperature is controlled to keep the target annealing temperature unchanged, and when the reduction of the band steel running speed is large, the corresponding annealing temperature is controlled to be reduced, so as to effectively reduce the grain boundary migration rate, and inhibit a part of large grains with high energy storage from forming a coarse grain structure by swallowing small grains, thereby achieving an effect of improving the grain size uniformity.
Further, compared with the prior art, the invention has the following beneficial effects: through the research of the inventor, the annealing temperature reduction amplitude is correspondingly and accurately adjusted corresponding to different value ranges of the running speed of the strip steel, the good matching of the running speed of the strip steel and the annealing temperature is realized, the mixed crystal defect is eliminated, and meanwhile, the deterioration of the mechanical property of the steel plate, such as the deterioration of the strength rise and the elongation rate reduction of the steel plate, caused by the reduction of the annealing temperature is avoided; moreover, the method is simple and easy to implement, and has obvious effect.
Drawings
FIG. 1 is a microstructure photograph of a hot-dip galvanized sheet in example 1 using the present invention;
FIG. 2 is a microstructure photograph of a hot-galvanized sheet in comparative example 2 using the prior art, in which the structure of the hot-galvanized sheet is shown to be slightly mixed-crystallized;
fig. 3 is a microstructure photograph of a hot-galvanized sheet in comparative example 4 using the prior art, in which the structure of the hot-galvanized sheet is shown to be severely miscrystallized.
Detailed Description
As described in the background art, it is conventionally generally believed that the mixed crystal defect of the hot-dip galvanized sheet is caused by the inheritance of the mixed crystal defect of the hot-rolled raw strip steel, and the prior art focuses on improving the processing and preparation process of the hot-rolled raw strip steel so as to achieve the purpose of eliminating the mixed crystal defect of the hot-dip galvanized sheet.
However, in actual production, even if the texture of the hot-rolled raw strip steel does not have obvious mixed crystal defects, when the corresponding cold-rolled strip steel is further processed into a hot-galvanized sheet, the obtained hot-galvanized sheet still often has mixed crystal defects, and the mixed crystal defects are different from the surface mixed crystal defects caused by the inheritance of the hot-rolled raw strip steel, and are represented by the existence of part of grains with obvious and coarse sizes on the surface layer and the core part of the hot-galvanized sheet.
In this regard, the inventors have found through extensive research and study that the mixed crystal defects are concentrated in the production process of the hot-galvanized sheet made of the cold-rolled steel strip, particularly in the deceleration production of the annealing process section in the production process, when the running speed of the steel strip is reduced relative to the target running speed of the steel strip, in other words, the running time of the steel strip in the annealing furnace is relatively increased.
The invention provides a solution to the technical problem, and specifically, an embodiment of the invention provides a preparation method of a hot-dip galvanized sheet and the hot-dip galvanized sheet prepared based on the preparation method.
The preparation method is basically characterized in that the cold-rolled strip steel is prepared into the hot-dip galvanized sheet through an annealing process and a hot-dip galvanizing process, the annealing process is implemented by adopting an annealing furnace on a production line, and the hot-dip galvanizing process is implemented by adopting a hot-dip galvanizing pot.
In summary, the preparation method comprises: inquiring a target annealing temperature T0 of an annealing furnace used by the annealing process and a target strip steel running speed U0 of the annealing furnace according to the parameters of the cold-rolled strip steel; and adjusting the running speed U of the strip steel of the annealing furnace to change from a state meeting U0-Ub and U0+ Ua to a state meeting U0-Ub, wherein Ua is more than or equal to 0m/min and less than or equal to 10m/min, Ub is more than or equal to 0m/min and less than or equal to 10m/min, and synchronously regulating and controlling the annealing temperature T of the annealing furnace to change from T0 to T which is more than or equal to T0.
That is, when the running speed U of the strip steel meets U0-Ub which is not less than U0+ Ua, the annealing temperature T which is T0 is controlled, and the structural grain size uniformity of the obtained hot-dip galvanized sheet is determined to be good through research; and when the running speed U of the strip steel is adjusted to be below U0-Ub downwards, the annealing temperature T is synchronously regulated and controlled to be less than T0, and the structure grain size uniformity of the obtained hot galvanized plate is good by controlling the annealing temperature T to be reduced relative to the target annealing temperature T0.
The technical principle of the present embodiment is explained in conjunction with the conventional operation as follows:
as described above, according to the parameters such as steel grade and specifications of size, thickness, etc. of the cold-rolled steel strip, the self-annealing process table of the annealing furnace used correspondingly gives a series of target values of the process parameters, such as the target strip running speed U0, the target annealing temperature T0; for cold-rolled steel strips with different parameters, such as two cold-rolled steel strips with different steel types, the target values of the process parameters in the self annealing process table of the same annealing furnace may be all the same, all different or partially different;
in actual production, after acquiring the current parameters of the cold-rolled strip steel of the production line, an operator can inquire a target annealing temperature T0 and a target strip steel running speed U0 corresponding to the current parameters of the cold-rolled strip steel in an annealing process table of the annealing furnace of the production line; thus, the operation of the annealing furnace can be controlled by referring to the target annealing temperature T0 and the target strip steel operation speed U0, and the conventional operation is to control the annealing furnace to operate at the target annealing temperature T0 and the target strip steel operation speed U0, namely to control the strip steel operation speed U of the annealing furnace to be U0 and the annealing temperature T to be T0;
moreover, in the existing operation, whether the running speed U of the steel strip is reduced (i.e. U is adjusted to be less than U0) or not due to the actual production situation (e.g. the production needs to be slowed down due to temporary equipment failure), the annealing temperature T is always kept unchanged (i.e. T is T0) at the target annealing temperature T0, so that the running time of the cold-rolled steel strip in the annealing furnace is increased, the heating period of the cold-rolled steel strip in the corresponding annealing process section is prolonged, the heating rate of the cold-rolled steel strip is relatively slowed down, the recrystallization nucleation rate in the structure is reduced, and small crystal grains with high part of stored energy preferentially nucleate, grow and continuously swallow new nucleation at the same time, and then part of the crystal grains grow abnormally, so that mixed crystal defects are finally caused;
in the embodiment, when the strip steel running speed U satisfies U0-Ub ≤ U0+ Ua, the running of the annealing process section is considered to be basically stable, slight changes of the strip steel running speed U do not affect the texture greatly, the annealing temperature T ═ T0 is controlled at this time, and the texture grain size uniformity of the obtained hot galvanized sheet is good; and when the running speed U of the strip steel is adjusted to be below U0-Ub downwards, the annealing temperature T is synchronously regulated and controlled to be less than T0, so that the grain boundary migration rate can be effectively reduced by controlling the annealing temperature T to be reduced relative to the target annealing temperature T0, a part of large grains with high energy storage are inhibited from forming coarse grain structures by swallowing small grains, and the effect of improving the grain size uniformity is achieved.
More preferably, in the embodiment, the step "adjusting the running speed U of the strip steel of the annealing furnace from the state satisfying U0-Ub ≤ U0+ Ua to the state satisfying U < U0-Ub, wherein 0m/min ≤ Ua is ≤ 10m/min, 0m/min ≤ Ub is ≤ 10m/min, and synchronously adjusting the annealing temperature T of the annealing furnace from the value T0 to T < T0" further includes:
controlling the running speed U of the strip steel of the annealing furnace to meet U0-Ub which is not less than U0+ Ua, and simultaneously controlling the annealing temperature T of the annealing furnace to meet T-T0, wherein Ua which is not less than 0m/min is not more than 10m/min, and Ub which is not less than 0m/min is not more than 10 m/min;
and adjusting the running speed U of the strip steel, and regulating and controlling the annealing temperature T0-Ta when the running speed U of the strip steel is adjusted to be U which is more than or equal to U0-Uc and less than U0-Ub, wherein Uc is more than or equal to 10m/min and less than or equal to 20m/min, and Ta is more than or equal to 5 ℃ and less than or equal to 10 ℃.
The inventor researches and discovers that when the running speed U of the strip steel is adjusted to be U0-Uc which is less than U0-Ub, the annealing temperature T-T0-Ta is regulated, the structural grain size uniformity of the obtained hot galvanized plate is good, compared with the prior art, the mixed crystal defect problem is eliminated, better mechanical property is maintained, and the deterioration of the mechanical property of the steel plate, such as the strength increase of the steel plate, the elongation reduction and the like, caused by the reduction of the annealing temperature is avoided.
Further, when the running speed U of the strip steel is adjusted: when the running speed U of the strip steel is adjusted to be U0-Ud which is more than or equal to U0-Uc, wherein Ud is more than or equal to 20m/min and less than or equal to 40m/min, the annealing temperature T is adjusted to be T0-Tb, wherein Tb is more than or equal to 15 ℃ and less than or equal to 20 ℃; and when the running speed U of the strip steel is adjusted to be U0-Ue which is more than or equal to U0-Ud, the annealing temperature T is adjusted to be T0-Tc, wherein Ue is more than or equal to 40m/min and less than or equal to 60m/min, and Tc is more than or equal to 25 ℃ and less than or equal to 30 ℃. Therefore, the obtained hot-dip galvanized sheet has good structural grain size uniformity, eliminates the problem of mixed crystal defects compared with the prior art, maintains better mechanical properties, and avoids the deterioration of the mechanical properties of the steel sheet, such as the deterioration of the strength increase and the elongation reduction of the steel sheet, caused by the reduction of the annealing temperature.
In summary, when the strip steel running speed U is adjusted downward to be less than U0-Ub, three levels of U0-Uc ≤ U < U0-Ub, U0-Ud ≤ U < U0-Uc, and U0-Ue ≤ U < U0-Ud are divided according to the adjustment range, and the corresponding adjustment range of the annealing temperature T is also divided into three levels of T0-Ta, T-T0-Tb, and T-T0-Tc, and the larger the reduction range of the strip steel running speed U is, the larger the adjustment range of the corresponding annealing temperature T is.
Therefore, according to the adjustment condition of the running speed U of the strip steel, the reduction amplitude of the annealing temperature T is correspondingly and accurately adjusted, the good matching of the running speed U of the strip steel and the annealing temperature T is realized, the mixed crystal defect is eliminated, and meanwhile, the deterioration of the mechanical property of the steel plate, such as the deterioration of the strength rise and the elongation rate reduction of the steel plate, caused by the reduction of the annealing temperature is avoided; moreover, the whole preparation method is simple and easy to implement, has obvious effect and high industrial value.
Wherein, Ua, Ub, Uc, Ud, Ue, Ta, Tb, Tc and the like take values in the respective ranges, and the specific values can be changed in the respective ranges according to the parameter difference of the cold-rolled strip steel and the self-difference of the annealing furnace.
Preferably, because factors such as chemical components of steel, cold rolling reduction and the like have influence on recrystallization of deformed ferrite, on the basis of the influence, the problem of mixed crystal defects of the cold-rolled low-carbon aluminum killed steel plate is particularly serious along with the speed reduction production of the annealing process section, and for the hot galvanized plate prepared from the cold-rolled low-carbon aluminum killed steel plate, the uniformity of the structure and the elongation after fracture influence two most important properties in the subsequent use, therefore, the embodiment is preferably suitable for the cold-rolled low-carbon aluminum killed steel plate selected as the cold-rolled strip steel, and mixed crystal defects generated due to the speed reduction production in the process of processing the cold-rolled low-carbon aluminum killed steel plate into the hot galvanized plate have unexpected elimination effect and do not damage the mechanical properties of the cold-rolled low-carbon aluminum killed steel plate.
Specifically, the cold-rolled low-carbon aluminum killed steel plate has a C content of 0.010-0.040% and a thickness of 0.4-1.6 mm.
Furthermore, in one embodiment, U0 takes a value within a range of 90m/min to 150m/min, and T0 takes a value within a range of 815 ℃ to 855 ℃; ua is 10m/min, Uc is 20m/min, Ub is 40m/min, and Ue is 60 m/min; ta is 10 ℃, Tb is 20 ℃ and Tc is 30 ℃, so that the mixed crystal defect generated by the existing operation can be obviously improved, the better mechanical property is maintained, and the product yield of the cold-rolled low-carbon aluminum killed steel hot-galvanized plate is greatly improved.
Further, the preparation method further comprises the following steps: and acquiring abnormal information of current production, and executing the adjustment of the running speed U of the strip steel according to the abnormal information. That is, when the abnormal production condition occurs in the current production, the running speed U of the strip steel is adjusted according to the abnormal condition, and whether the running speed U of the strip steel is matched with U0-Uc which is more than or equal to U0-Ub, U0-Ud which is more than or equal to U0-Uc, U0-Ue which is more than or equal to U0-Ud or not is judged. Of course, it can be understood that, when the "adjustment of the strip steel running speed U" is performed according to the abnormality information, if the adjusted strip steel running speed U satisfies U0-Ub ≦ U0+ Ua, the annealing temperature T ≦ T0 is controlled.
Preferably, in the preparation method, the cold-rolled strip steel is prepared into the hot-dip galvanized sheet by adopting a continuous hot-dip galvanizing unit through a cleaning process, an annealing process, a hot-dip galvanizing process, a leveling, pulling and straightening process and a post-treatment process in sequence; the continuous hot galvanizing unit comprises a cleaning device for implementing the cleaning process, the annealing furnace for implementing the annealing process, a hot-dip galvanizing kettle for implementing the hot-dip galvanizing process, leveling and straightening equipment (including a leveling machine and a straightening and withdrawal machine, for example) for implementing the leveling and straightening process, and processing equipment for implementing the post-processing process.
The abnormality information preferably includes a failure in any of the hot-dip galvanizing kettle, the leveling withdrawal device, and the treatment device. That is, when equipment abnormality occurs in a process stage subsequent to the annealing process stage, the strip steel running speed U is adjusted. Of course, the abnormality information is not limited thereto.
Furthermore, the invention also provides the hot-dip galvanized sheet prepared by the preparation method according to any one of the embodiments, the hot-dip galvanized sheet has good structural grain size uniformity, and compared with the prior art, the hot-dip galvanized sheet eliminates the problem of mixed crystal defects and maintains better mechanical properties.
The present invention is further described below by way of examples 1 to 7 in combination with comparative examples 1 to 4.
Preparing the cold-rolled strip steel shown in the table 1 into a hot-galvanized sheet by adopting a continuous hot galvanizing unit through a cleaning process, an annealing process, a hot-dip galvanizing process, a leveling and straightening process and a post-treatment process in sequence; wherein:
according to the parameters of the thickness, the steel grade, the C content and the like of the cold-rolled steel strip shown in the table 1, inquiring the target annealing temperature T0 and the target running speed U0 of the annealing furnace of the continuous hot galvanizing unit as shown in the table 1;
controlling the annealing furnace to operate at a target annealing temperature T0 and a target strip steel operation speed U0 during the normal operation period in the production process; when the speed reduction production is required according to the actual production condition (for example, due to equipment failure) in the production process, the annealing temperature T is controlled to be correspondingly adjusted according to the adjustment range required by the running speed U of the strip steel of the annealing furnace in the embodiments 1 to 7 and shown in the table 1; in comparative examples 1 to 4, the target annealing temperature T0 was always maintained as shown in Table 2 according to the conventional operation;
among them, it can be understood that the duration of the down-run production mentioned in the present application is short and the back-annealing furnace is finished, i.e., the normal operation is resumed at the target annealing temperature T0 and the target strip steel operation speed U0;
[ Table 1]
Finally, the hot-galvanized sheets obtained in examples 1 to 7 and comparative examples 1 to 4 are respectively subjected to structure, performance and other aspects of detection, and the detection results are shown in table 2, wherein a microstructure photo of the hot-galvanized sheet obtained in example 1 is shown in fig. 1, a microstructure photo of the hot-galvanized sheet obtained in comparative example 2 is shown in fig. 2, and a microstructure photo of the hot-galvanized sheet obtained in comparative example 4 is shown in fig. 3;
[ Table 2]
As can be seen from the above examples and comparative examples, in the present embodiment, when the annealing process is performed at the speed reduction production, the corresponding controlled annealing temperature is reduced relative to the target annealing temperature, and the reduction amplitude (or the difference between the controlled annealing temperature and the target annealing temperature) is precisely controlled, so that not only the mixed crystal defect is eliminated, but also the deterioration of the mechanical property of the steel plate, such as the increase of the strength of the steel plate, the decrease of the elongation percentage, and the like, caused by the reduction of the annealing temperature is avoided, and especially for the cold-rolled low-carbon aluminum killed steel plate mainly used for stamping, the structure uniformity is improved while the high elongation percentage is maintained, the mixed crystal defect is eliminated, and the quality performance of the cold-rolled low-carbon.
The detailed description set forth above is merely a specific description of possible embodiments of the present invention and is not intended to limit the scope of the invention, which is intended to include within the scope of the invention equivalent embodiments or modifications that do not depart from the technical spirit of the present invention.
For example, although the technical solution is described based on "strip steel running speed" in the present invention, it can be understood that, in the actual production implementation, the "strip steel running speed" may be directly presented in the annealing process table of the annealing furnace or in the controller of the annealing furnace as an indicative parameter, or the "duration/time" may be presented in the annealing process table of the annealing furnace or in the controller of the annealing furnace as an indicative parameter, and the relationship between the "duration/time" and the time, the speed and the distance may be reasonably converted into the "strip steel running speed" based on the essence of the present invention. Surface variations such as these do not depart from the essence of the invention and are intended to be within the scope of the invention.
Claims (10)
1. A preparation method of hot galvanized plates is characterized in that cold-rolled strip steel is prepared into hot galvanized plates through an annealing process and a hot-dip galvanizing process, and the preparation method comprises the following steps:
inquiring a target annealing temperature T0 and a target strip steel running speed U0 of an annealing furnace used by the annealing process according to the parameters of the cold-rolled strip steel;
controlling the running speed U of the strip steel of the annealing furnace to meet U0-Ub which is not less than U0+ Ua, and simultaneously controlling the annealing temperature T of the annealing furnace to meet T-T0, wherein Ua which is not less than 0m/min is not more than 10m/min, and Ub which is not less than 0m/min is not more than 10 m/min;
and adjusting the running speed U of the strip steel, and regulating and controlling the annealing temperature T0-Ta when the running speed U of the strip steel is adjusted to be U which is more than or equal to U0-Uc and less than U0-Ub, wherein Uc is more than or equal to 10m/min and less than or equal to 20m/min, and Ta is more than or equal to 5 ℃ and less than or equal to 10 ℃.
2. The method for preparing a hot-dip galvanized sheet according to claim 1, wherein, in the step of "adjusting the running speed U of the strip steel":
when the running speed U of the strip steel is adjusted to be U (more than or equal to U) 0-Ud and U (less than U) 0-Uc, the annealing temperature T is adjusted to be T0-Tb, wherein Ud is more than or equal to 20m/min and less than or equal to 40m/min, Tb is more than or equal to 15 ℃ and less than or equal to 20 ℃;
when the running speed U of the strip steel is adjusted to be U (equal to or greater than U) 0-Ue and U (equal to or less than U0-Ud), the annealing temperature T is adjusted to be T0-Tc, wherein Ue is equal to or greater than 40m/min and equal to or less than 60m/min, and Tc is equal to or greater than 25 ℃ and equal to or less than 30 ℃.
3. The method for producing a hot-galvanized sheet according to claim 2, characterized in that the parameters include specification and steel grade;
the cold-rolled strip steel is a cold-rolled low-carbon aluminum killed steel plate, the content of C is 0.010-0.040%, and the thickness is 0.4-1.6 mm.
4. The method for preparing the hot-galvanized sheet according to claim 3, wherein U0 is selected from the range of 90m/min to 150m/min, and T0 is selected from the range of 815 ℃ to 855 ℃.
5. The method for preparing a hot-galvanized sheet according to claim 4, wherein Ua is 10m/min, Uc is 20m/min, Ud is 40m/min, and Ue is 60 m/min;
Ta＝10℃，Tb＝20℃，Tc＝30℃。
6. the method for producing a hot-dip galvanized sheet according to any one of claims 1 to 5, characterized by further comprising:
and acquiring abnormal information of current production, and executing the adjustment of the running speed U of the strip steel according to the abnormal information.
7. The method for preparing hot-galvanized sheets according to claim 6, characterized in that the cold-rolled strip steel is prepared into the hot-galvanized sheets by adopting a continuous hot galvanizing unit and sequentially performing a cleaning process, the annealing process, the hot-dip galvanizing process, a leveling and straightening process and a post-treatment process;
the continuous hot galvanizing unit comprises a cleaning device for implementing the cleaning process, the annealing furnace for implementing the annealing process, a hot-dip galvanizing kettle for implementing the hot-dip galvanizing process, leveling and straightening equipment for implementing the leveling and straightening process, and treatment equipment for implementing the post-treatment process.
8. The method of producing hot-galvanized sheets according to claim 7, characterized in that the abnormality information includes that any several of the hot-dip galvanizing kettle, the leveling and straightening equipment, and the processing equipment are malfunctioning.
9. A preparation method of hot galvanized plates is characterized in that cold-rolled strip steel is prepared into hot galvanized plates through an annealing process and a hot-dip galvanizing process, and the preparation method comprises the following steps:
inquiring a target annealing temperature T0 of an annealing furnace used by the annealing process and a target strip steel running speed U0 of the annealing furnace according to the parameters of the cold-rolled strip steel;
when the running speed U of the strip steel of the annealing furnace is adjusted to change from the state that U is not less than U0+ Ua and is not less than U0-Ub to the state that U is not less than U0-Ub, the annealing temperature T of the annealing furnace is synchronously regulated and controlled to change from the value T0 to the value T is less than T0, wherein Ua is not less than 0m/min and is not more than 10m/min, and Ub is not less than 0m/min and is not more than 10 m/min.
10. A hot-dip galvanized sheet, characterized by being produced by the production method according to claim 1 or 9.
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Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4878961A (en) * | 1986-09-30 | 1989-11-07 | Kawasaki Steel Corp. | Method and system for controlling tension to be exerted on metal strip in continuous annealing furnace |
| JPH11124635A (en) * | 1997-10-17 | 1999-05-11 | Kobe Steel Ltd | Method of controlling continuous annealing furnace |
| CN102886383A (en) * | 2011-07-22 | 2013-01-23 | 宝山钢铁股份有限公司 | Method for controlling mechanical properties of cold-rolling strip steel in online manner |
| CN104046890A (en) * | 2014-06-09 | 2014-09-17 | 首钢总公司 | High-yield-ratio hot-galvanized micro-carbo/aluminum killed steel plate and production method thereof |
| CN107674945A (en) * | 2017-09-14 | 2018-02-09 | 首钢京唐钢铁联合有限责任公司 | A kind of annealing furnace temprature control method and system |
| CN108384944A (en) * | 2018-02-26 | 2018-08-10 | 首钢京唐钢铁联合有限责任公司 | A method of preventing strip, wooden dipper is bent in the lehr |
| CN108500066A (en) * | 2017-02-24 | 2018-09-07 | 上海梅山钢铁股份有限公司 | The thick difference in T5 hard tinned plates tail portion is cold and hot to roll work preface moderate control method |
| CN109207711A (en) * | 2018-10-22 | 2019-01-15 | 攀钢集团西昌钢钒有限公司 | A kind of wrinkle resistant control method of 0.4mm strip IF steel continuous annealing |
| US20190127821A1 (en) * | 2015-07-10 | 2019-05-02 | Salzgitter Fachstahl GmbH | Ultra high strength multi-phase steel and method for producing a cold-rolled steel strip therefrom |
| CN110551889A (en) * | 2018-06-01 | 2019-12-10 | 上海梅山钢铁股份有限公司 | rapid shutdown control method for thin plate of vertical continuous annealing unit |
| CN110607435A (en) * | 2019-09-05 | 2019-12-24 | 中国地质大学（武汉） | Annealing furnace plate temperature control system and method |
| CN110714116A (en) * | 2019-11-05 | 2020-01-21 | 山东钢铁集团日照有限公司 | Method for stopping in thin-specification strip steel annealing furnace for rapid production recovery |
-
2020
- 2020-04-30 CN CN202010364411.4A patent/CN111519016B/en active Active
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4878961A (en) * | 1986-09-30 | 1989-11-07 | Kawasaki Steel Corp. | Method and system for controlling tension to be exerted on metal strip in continuous annealing furnace |
| JPH11124635A (en) * | 1997-10-17 | 1999-05-11 | Kobe Steel Ltd | Method of controlling continuous annealing furnace |
| CN102886383A (en) * | 2011-07-22 | 2013-01-23 | 宝山钢铁股份有限公司 | Method for controlling mechanical properties of cold-rolling strip steel in online manner |
| CN104046890A (en) * | 2014-06-09 | 2014-09-17 | 首钢总公司 | High-yield-ratio hot-galvanized micro-carbo/aluminum killed steel plate and production method thereof |
| US20190127821A1 (en) * | 2015-07-10 | 2019-05-02 | Salzgitter Fachstahl GmbH | Ultra high strength multi-phase steel and method for producing a cold-rolled steel strip therefrom |
| CN108500066A (en) * | 2017-02-24 | 2018-09-07 | 上海梅山钢铁股份有限公司 | The thick difference in T5 hard tinned plates tail portion is cold and hot to roll work preface moderate control method |
| CN107674945A (en) * | 2017-09-14 | 2018-02-09 | 首钢京唐钢铁联合有限责任公司 | A kind of annealing furnace temprature control method and system |
| CN108384944A (en) * | 2018-02-26 | 2018-08-10 | 首钢京唐钢铁联合有限责任公司 | A method of preventing strip, wooden dipper is bent in the lehr |
| CN110551889A (en) * | 2018-06-01 | 2019-12-10 | 上海梅山钢铁股份有限公司 | rapid shutdown control method for thin plate of vertical continuous annealing unit |
| CN109207711A (en) * | 2018-10-22 | 2019-01-15 | 攀钢集团西昌钢钒有限公司 | A kind of wrinkle resistant control method of 0.4mm strip IF steel continuous annealing |
| CN110607435A (en) * | 2019-09-05 | 2019-12-24 | 中国地质大学（武汉） | Annealing furnace plate temperature control system and method |
| CN110714116A (en) * | 2019-11-05 | 2020-01-21 | 山东钢铁集团日照有限公司 | Method for stopping in thin-specification strip steel annealing furnace for rapid production recovery |
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