CN114369707A - Strip steel without flat coil defect and color difference defect and preparation method and application thereof - Google Patents
Strip steel without flat coil defect and color difference defect and preparation method and application thereof Download PDFInfo
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- CN114369707A CN114369707A CN202111472414.0A CN202111472414A CN114369707A CN 114369707 A CN114369707 A CN 114369707A CN 202111472414 A CN202111472414 A CN 202111472414A CN 114369707 A CN114369707 A CN 114369707A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 146
- 239000010959 steel Substances 0.000 title claims abstract description 146
- 230000007547 defect Effects 0.000 title claims abstract description 93
- 238000002360 preparation method Methods 0.000 title claims abstract description 8
- 238000001816 cooling Methods 0.000 claims abstract description 125
- 238000000034 method Methods 0.000 claims abstract description 51
- 238000005096 rolling process Methods 0.000 claims abstract description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 24
- 238000004519 manufacturing process Methods 0.000 claims description 13
- 239000012535 impurity Substances 0.000 claims description 6
- 239000002356 single layer Substances 0.000 claims description 6
- 239000000126 substance Substances 0.000 claims description 6
- 239000000203 mixture Substances 0.000 claims description 2
- 230000000052 comparative effect Effects 0.000 description 36
- 230000000694 effects Effects 0.000 description 28
- 230000002411 adverse Effects 0.000 description 25
- 230000008569 process Effects 0.000 description 18
- 230000008092 positive effect Effects 0.000 description 17
- 238000003860 storage Methods 0.000 description 10
- 239000002344 surface layer Substances 0.000 description 7
- 229910001562 pearlite Inorganic materials 0.000 description 6
- 230000009466 transformation Effects 0.000 description 6
- 238000005097 cold rolling Methods 0.000 description 5
- 230000035882 stress Effects 0.000 description 5
- 229910001563 bainite Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 238000005336 cracking Methods 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 239000000498 cooling water Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 238000000137 annealing Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000009628 steelmaking Methods 0.000 description 2
- 229910000859 α-Fe Inorganic materials 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 1
- 229910001566 austenite Inorganic materials 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 235000012771 pancakes Nutrition 0.000 description 1
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- 238000004088 simulation Methods 0.000 description 1
- 239000006104 solid solution Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
- 230000006032 tissue transformation Effects 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
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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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
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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
- C21D11/005—Process control or regulation for heat treatments for cooling
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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
- C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
- C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
- C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium with molybdenum or tungsten
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/38—Ferrous alloys, e.g. steel alloys containing chromium with more than 1.5% by weight of manganese
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
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Abstract
The application relates to the technical field of steel rolling treatment, in particular to a strip steel without flat coil defects and color difference defects and a preparation method thereof; the method comprises the following steps: obtaining a steel coil after finish rolling; carrying out ultra-fast cooling on the steel coil, and then carrying out air cooling and laminar cooling to obtain a cooled steel coil; coiling the cooled steel coil, and then idling and unloading to obtain the hot-coiled steel coil; storing the hot rolled steel coil to obtain strip steel without flat coil defects and color difference defects; wherein the hydraulic pressure of the ultra-fast cooling is 0.3MPa to 0.9MPa, and the coiling temperature is 520 ℃ to 560 ℃; the strip steel is prepared by the method; the application comprises the following steps: the strip steel prepared by the method is used for preparing a high-strength automobile plate; by the method, the flat roll defect and the color difference defect can be synchronously controlled, so that the strip steel without the flat roll defect and the color difference defect can be obtained.
Description
Technical Field
The application relates to the technical field of steel rolling treatment, in particular to a strip steel without flat coil defects and color difference defects and a preparation method thereof.
Background
Along with the development of the automobile industry towards the direction of reducing weight, saving energy and improving safety, the high-strength automobile plate is more and more widely applied to automobiles, steel can be saved and the oil consumption of automobiles can be reduced by the application of the high-strength automobile plate, the high-strength automobile plate is an important material for realizing the light weight of automobile bodies, the high-strength automobile plate is strip steel which is obtained by discharging hot rolled plate coils from a coiling machine, the obtained strip steel is generally placed into a coil stock for storage in a horizontal transportation mode, but the phenomenon of flat coils is easy to occur in the storage process: the side shape of the steel coil is changed from circular shape after the coiling is finished into elliptical shape, so that the subsequent cold rolling process cannot be smoothly rolled up.
At present, aiming at the defect, the coiling temperature of a hot coil is mainly increased, but the high-strength automobile plate has another defect, namely a surface color difference defect which needs to be shown after cold rolling and annealing, the surface color difference defect is controlled, and the coiling temperature of the hot coil needs to be reduced, so that the hardness and the anti-cracking capability of a surface layer are improved, therefore, the core technologies of the high-strength automobile plate for controlling the flat coil defect and the surface color difference defect are opposite in the prior art, namely, the seesaw effect exists in the control of the two types of defects, and therefore, the technical problem to be solved at present is how to obtain the strip steel without the flat coil defect and the color difference defect.
Disclosure of Invention
The application provides a band steel without flat coil defects and color difference defects and a preparation method thereof, which aim to solve the technical problem that the band steel without flat coil defects and color difference defects is difficult to prepare in the prior art.
In a first aspect, the present application provides a method for preparing a steel strip without edge curl defects and color difference defects, the method comprising:
obtaining a steel coil after finish rolling;
carrying out ultra-fast cooling on the steel coil, and then carrying out air cooling and laminar cooling to obtain a cooled steel coil;
coiling the cooled steel coil, and then idling and unloading to obtain the hot-coiled steel coil;
storing the hot rolled steel coil to obtain strip steel without flat coil defects and color difference defects;
wherein the hydraulic pressure of the ultra-fast cooling is 0.3MPa to 0.9MPa, and the coiling temperature is 520 ℃ to 560 ℃.
Optionally, will the coil of strip carries out ultrafast cooling, and air cooling and laminar flow cooling carry out afterwards, obtain the coil of strip after the cooling, specifically include:
respectively obtaining the actual thickness and the preset thickness of the steel coil;
judging whether the water pressure of the ultra-fast cooling is a first preset pressure or a second preset pressure according to the actual thickness and the preset thickness;
if the actual thickness is larger than or equal to the preset thickness, judging that the water pressure of the ultra-fast cooling is a first preset pressure;
if the actual thickness is smaller than the preset thickness, judging that the water pressure of the ultra-fast cooling is a second preset pressure;
and carrying out ultrafast cooling according to the first preset pressure or the second preset pressure, and then carrying out air cooling and laminar cooling to obtain the cooled steel coil.
Optionally, the preset thickness is more than or equal to 4 mm.
Optionally, the first preset pressure is 0.5MPa to 0.9MPa, and the second preset pressure is 0.3MPa to 0.7 MPa.
Optionally, the final temperature of the ultra-fast cooling is 580-620 ℃; the idling time is 40-60 s.
Optionally, the laminar cooling includes: laminar cooling in a dense cooling mode;
the storing comprises: and (4) storing in a single-layer stacking mode.
In a second aspect, the present application provides a steel strip free of edge roll defects and color difference defects, the steel strip produced by the method of the first aspect.
Optionally, the chemical components of the strip steel by mass fraction include:
c: 0.05 to 0.13 percent, Si: 0.03 to 0.6 percent, Mn: 1.0-2.0%, P is less than or equal to 0.03%, S is less than or equal to 0.07%, Alt: 0.03 to 0.07 percent of Cr: 0.1% -0.4%, Mo: 0.15 to 0.25 percent, and the balance of Fe and inevitable impurities.
In a third aspect, the present application provides a use of the steel strip of the second aspect for the manufacture of high-strength automotive panels without edge curl defects and color difference defects.
Compared with the prior art, the technical scheme provided by the embodiment of the application has the following advantages:
the embodiment of the application provides a preparation method of band steel without flat coil defects and color difference defects, which comprises the steps of firstly adopting a three-section combined cooling mode of ultra-fast cooling, air cooling and laminar cooling to control the hydraulic pressure of the ultra-fast cooling so as to control the cooling speed of the ultra-fast cooling, then controlling the coiling temperature, combining the ultra-fast cooling with the coiling temperature so as to fully control the tissue transformation condition in a steel coil, generating uniform temperature field and internal stress in the cooling process, improving the flat coil defects of the band steel, simultaneously improving the surface hardness and the anti-cracking capacity of the steel coil, improving the surface color difference defects of the band steel, idle running after controlling the coiling, increasing the overall hoop strength of the steel coil, reducing the loose coil degree caused by expansion of a hot coil, reducing the possibility of the occurrence of the flat coil defects in the storage stage, realizing the synchronous control of the flat coil defects and the color difference of the defects, thereby obtaining the strip steel without flat coil defect and color difference defect.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without inventive exercise.
Fig. 1 is a schematic flow chart of a method provided in an embodiment of the present application;
FIG. 2 is a schematic flow chart illustrating a method according to an embodiment of the present disclosure;
fig. 3 is a schematic diagram of a CCT curve of a DP590 type steel coil provided in this embodiment;
FIG. 4 is a schematic illustration of a high-strength automotive sheet produced by a conventional process according to the comparative example of the present application showing a flat coil defect;
FIG. 5 is a schematic view of a high-strength automotive sheet produced by the method of the present application without a flat-roll defect;
FIG. 6 is a schematic view of the distribution of the inside diameter of the hot coil of the high-strength automobile sheet produced by the method according to the embodiment of the present application;
FIG. 7 is a schematic view of a high-strength automobile sheet produced by conventional companies according to an embodiment of the present application showing surface color difference defects;
FIG. 8 is a schematic view of a high-strength automobile sheet produced by the method of the present application without surface color difference defects.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all 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 application.
The inventive ideas of the present application include:
the conventional pancake phenomenon is a non-uniform temperature field and internal thermal stress generated in a cooling process, and volume expansion caused by phase change; the conventional surface color difference defect is that the surface of the hot coil has rough interface and shallow surface layer rolling crack, and the surface of the hot coil is further aggravated in the subsequent cold rolling process so as to be macroscopically represented as color difference, and the two defects have a seesaw effect in principle, so a balance point needs to be found.
Meanwhile, a CCT curve and a phase change key temperature point of a typical steel grade continuous annealing DP590 and the like of the high-strength automobile plate are determined in advance by adopting a thermal simulation method, and as shown in figure 3, accurate data support is provided for optimization of process parameters through the CCT curve.
In one embodiment of the present application, as shown in fig. 1, there is provided a method of manufacturing a steel strip without a flat coil defect and a color difference defect, the method comprising:
s1, obtaining a steel coil after finish rolling;
s2, carrying out ultra-fast cooling on the steel coil, and then carrying out air cooling and laminar cooling to obtain a cooled steel coil;
s3, coiling the cooled steel coil, idling and unloading the steel coil to obtain the hot-coiled steel coil;
s4, storing the hot rolled steel coil to obtain strip steel without flat coil defects and color difference defects;
wherein the hydraulic pressure of the ultra-fast cooling is 0.3MPa to 0.9MPa, and the coiling temperature is 520 ℃ to 560 ℃.
In the application, the hydraulic pressure of the ultra-fast cooling is 0.3 MPa-0.9 MPa, and the positive effect is that in the pressure range, the cooling speed can be controlled, and the faster the cooling speed is, the bainite transformation of the finish-rolled steel coil can be quickly started, so that the phase transformation of the steel coil on the laminar cooling can be completed as much as possible, and the phase transformation expansion amount after coiling can be reduced; when the value of the water pressure is larger than the maximum value of the end point of the range, the adverse effect is that the pressure is too large, the running stability of the strip steel is affected, and when the value of the water pressure is smaller than the minimum value of the end point of the range, the adverse effect is that the pressure is too small, and the rapid cooling cannot be realized.
The coiling temperature is 520-560 ℃, the positive effect is that in the storage process after the steel coil is coiled into the hot coil, the metallographic structure of the steel coil is transformed from the austenite structure in the high-temperature state to the bainite or ferrite in the low-temperature state, and the coiling temperature is one of the main factors influencing the transformation type of the steel coil, and in the temperature range, the transformation from the metallographic structure to the bainite in the storage process of the hot coil can be controlled, and the fine bainite structure can improve the hardness of the surface layer, so that the rolling crack of the shallow surface layer in the subsequent cold rolling process can be avoided, and the surface color difference defect of the strip steel can be avoided; when the value of the temperature is larger than the maximum value of the end point of the range, the adverse effect is that a large amount of pearlite is generated on the surface layer of the strip steel due to the overhigh coiling temperature, the cracking resistance of the pearlite structure is poor due to the small hardness of the pearlite structure, the surface layer of the strip steel is rolled and cracked, and the surface color difference defect of the strip steel is caused.
As an optional implementation manner, the ultra-fast cooling is performed on the steel coil, and then air cooling and laminar cooling are performed on the steel coil, so as to obtain a cooled steel coil, which specifically includes:
s21, respectively obtaining the actual thickness and the preset thickness of the steel coil;
s22, judging whether the water pressure of the ultra-fast cooling is a first preset pressure or a second preset pressure according to the actual thickness and the preset thickness;
if the actual thickness is larger than or equal to the preset thickness, judging that the water pressure of the ultra-fast cooling is a first preset pressure;
if the actual thickness is smaller than the preset thickness, judging that the water pressure of the ultra-fast cooling is a second preset pressure;
and S23, carrying out ultrafast cooling according to the first preset pressure or the second preset pressure, and then carrying out air cooling and laminar cooling to obtain the cooled steel coil.
In this application, through the cooling water pressure of the super fast cold of actual thickness adjustment according to the coil of strip to can further control cooling rate, thereby the metallographic structure transformation process in the control coil of strip improves the internal stress of coil of strip and the hardness on top layer, and then can obtain the belted steel that does not have flat coil defect and colour difference defect.
As an optional embodiment, the preset thickness is more than or equal to 4 mm.
In the application, the positive effect that the preset thickness is more than or equal to 4mm is that different steel coils can be distinguished by the preset thickness within the preset thickness range, and meanwhile, different cooling water pressures of ultra-fast cooling are correspondingly set, so that the cooling speed of the ultra-fast cooling is accurately controlled; when the value of the preset thickness is smaller than the minimum value of the end point of the range, the adverse effect to be caused is that the excessively low preset thickness causes inaccurate water pressure of ultra-fast cooling, the cooling speed is excessively high, the metallographic structure and the stress condition of the steel coil are influenced, and meanwhile, the hardness of the surface layer cannot be improved.
As an optional embodiment, the first preset pressure is 0.5MPa to 0.9MPa, and the second preset pressure is 0.3MPa to 0.7 MPa.
In the application, the positive effect that the first preset pressure is 0.5 MPa-0.9 MPa is that the balance of rapid cooling and stable production can be realized within the pressure range; when the value of the first preset pressure is larger than the maximum value of the end point of the range, the adverse effect is that the pressure is too large, the running stability of the strip steel is affected, and when the value of the first preset pressure is smaller than the minimum value of the end point of the range, the adverse effect is that the pressure is too small, and the rapid cooling cannot be realized.
The second preset pressure of 0.3 MPa-0.7 MPa has the positive effects that the balance of rapid cooling and stable production can be realized within the pressure range; when the value of the second preset pressure is larger than the maximum value of the end point of the range, the adverse effect is that the pressure is too large, the running stability of the strip steel is affected, and when the value of the second preset pressure is smaller than the minimum value of the end point of the range, the adverse effect is that the pressure is too small, and the rapid cooling cannot be realized.
As an alternative embodiment, the final temperature of the ultra-fast cooling is 580-620 ℃; the idling time is 40-60 s.
In the application, the positive effect that the final temperature of the ultra-fast cooling is 580-620 ℃ is that the surface structure of the strip steel can be strengthened in the temperature range; when the value of the end point temperature is larger than the maximum value of the end point of the range, the adverse effect is that the temperature is too high, the surface strength of the strip steel is insufficient, and the surface defect cannot be effectively avoided.
The idling time is 40-60 s, and the positive effect is that in the coiling process, the steel coil can continuously generate phase change, so that expansion and uncoiling can occur, and in the time range, the overall hoop stress of the steel coil can be fully increased, and the uncoiling degree caused by expansion of the hot coil is reduced, so that the flat coil phenomenon in the subsequent storage process is relieved, and the possibility of flat coil defects is reduced; when the time value is larger than the maximum value of the end point of the range, the adverse effect is too long time and affects the production efficiency, and when the time value is smaller than the minimum value of the end point of the range, the adverse effect is too short time and the flat roll defect cannot be eliminated.
As an alternative embodiment, the laminar cooling comprises: laminar cooling in a dense cooling mode;
the storing comprises: and (4) storing in a single-layer stacking mode.
In the application, the laminar cooling adopting the intensive cooling mode has the positive effect that the cooling mode is adopted, and the proper cooling speed can be ensured.
The positive effect of adopting the deposit of individual layer mode of piling up has been avoided the extrusion of upper coil of strip, reduces the risk of aggravating.
In one embodiment of the application, a steel strip without flat coil defects and color difference defects is provided, and the steel strip is prepared by the method;
as an optional embodiment, the chemical composition of the steel strip comprises the following components in percentage by mass:
c: 0.05 to 0.13 percent, Si: 0.03 to 0.6 percent, Mn: 1.0-2.0%, P is less than or equal to 0.03%, S is less than or equal to 0.07%, Alt: 0.03 to 0.07 percent of Cr: 0.1% -0.4%, Mo: 0.15 to 0.25 percent, and the balance of Fe and inevitable impurities.
In the application, the positive effect that the mass fraction of C is 0.05-0.13% is that in the mass fraction range, the C element can form appropriate solid solution structures such as ferrite, pearlite and the like, when the mass fraction is larger than the maximum value of the end point of the range, the adverse effect is that the C content is too high, the pearlite proportion in the strip steel is too high, and when the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect is that the C content is too low, and the pearlite proportion in the strip steel is too low.
The positive effect that the mass fraction of Si is 0.03-0.6% is that in the mass fraction range, a strip steel with proper hardenability and strength can be obtained, when the mass fraction is larger than the maximum value of the end point of the range, the adverse effect is that the Si content is too high, the strength of the strip steel is too high, and when the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect is that the Si content is too low, and the strength of the strip steel is insufficient.
The positive effect that the mass fraction of Mn is 1.0-2.0% is that in the mass fraction range, a strip steel with proper hardenability and strength can be obtained, when the mass fraction is larger than the maximum value of the end point of the range, the adverse effect is that the content of Mn is too high, the strip steel has temper brittleness, and when the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect is that the content of Mn is too low, and the strip steel has insufficient strength.
The positive effect that P is less than or equal to 0.03 percent is that the low-temperature brittleness of the strip steel can be avoided within the mass fraction range, and when the value of the mass fraction is greater than the maximum value of the end point of the range, the adverse effect is that the P content is too high, and the strip steel generates low-temperature brittleness.
The positive effect that S is less than or equal to 0.07 percent is that the hot brittleness of the strip steel can be avoided within the mass fraction range, and when the value of the mass fraction is greater than the maximum value of the end point of the range, the adverse effect caused is that the S content is too high, and the strip steel generates hot brittleness.
The positive effect that the mass fraction of Alt is 0.03-0.07 percent is that in the mass fraction range, Al can be used as a deoxidizer in steel making and the strength of strip steel is improved, when the value of the mass fraction is larger than the maximum value of the end point of the range, the adverse effect caused by the fact that the content of Al is too high, the steel making is difficult, the strength of the strip steel is too high, and when the value of the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect caused by the fact that the content of Al is insufficient, the strip steel is not fully deoxidized, and the strength of the strip steel is insufficient.
The positive effect that the mass fraction of Cr is 0.1-0.4% is that in the mass fraction range, the good hardenability of the strip steel can be ensured, when the value of the mass fraction is larger than the maximum value of the end point of the range, the adverse effect is that the content of Cr is too high, the strength of the strip steel is high, the production cost is improved, and when the value of the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect is that the content of Cr is too low, and the strength of the strip steel is insufficient.
The positive effect that the mass fraction of Mo is 0.15-0.25% is that in the mass fraction range, the good hardenability of the strip steel can be ensured, when the value of the mass fraction is larger than the maximum value of the end point of the range, the adverse effect caused is that the strength of the strip steel is high, and simultaneously the production cost is improved, and when the value of the mass fraction is smaller than the minimum value of the end point of the range, the adverse effect caused is that the Cr content is too low, and the strength of the strip steel is insufficient.
In one embodiment of the present application, there is provided the use of a method for producing a steel strip free of edge roll defects and color shading defects for use in the production of high-strength automotive panels.
Example 1
A preparation method of strip steel without flat coil defects and color difference defects comprises the following steps:
s1, obtaining a finish rolled steel coil, wherein the model of the steel coil is DP 590;
s21, respectively obtaining the actual thickness of the steel coil to be 4mm and the preset thickness to be 4 mm;
s22, judging that the water pressure of the ultra-fast cooling adopts a first preset pressure according to the actual thickness and the preset thickness;
s23, carrying out ultrafast cooling according to the first preset pressure or the second preset pressure, and then carrying out air cooling and laminar cooling to obtain a cooled steel coil;
s3, coiling the cooled steel coil, idling and unloading the steel coil to obtain the hot-coiled steel coil;
s4, storing the hot rolled steel coil to obtain strip steel without flat coil defects and color difference defects;
wherein the coiling temperature is 550 ℃.
The first preset pressure is 0.6 MPa.
The final temperature of the ultra-fast cooling is 600 ℃; the time of idling was 50 s.
Laminar cooling includes: laminar cooling in a dense cooling mode;
the storage comprises the following steps: and (4) storing in a single-layer stacking mode.
A strip steel without flat coil defects and color difference defects comprises the following chemical components in percentage by mass:
c: 0.1%, Si: 0.4%, Mn: 1.0%, P: 0.03%, S: 0.05%, Alt: 0.04%, Cr: 0.3%, Mo: 0.2% and the balance of Fe and inevitable impurities.
Example 2
Comparing example 2 with example 1, example 2 differs from example 1 in that:
the coiling temperature was 520 ℃.
The first preset pressure is 0.5 MPa.
The final temperature of the ultra-fast cooling is 580 ℃; the time of idling was 50 s.
Laminar cooling includes: laminar cooling in a dense cooling mode;
the storage comprises the following steps: and (4) storing in a single-layer stacking mode.
A strip steel without flat coil defects and color difference defects comprises the following chemical components in percentage by mass:
c: 0.05%, Si: 0.03%, Mn: 1.0%, P: 0.03%, S: 0.07%, Alt: 0.03%, Cr: 0.1%, Mo: 0.15%, and the balance of Fe and inevitable impurities.
Examples3
Comparing example 3 with example 1, example 3 differs from example 1 in that:
the coiling temperature was 560 ℃.
The first preset pressure is 0.9 MPa.
The final temperature of the ultra-fast cooling is 620 ℃; the time of idling was 60 s.
A strip steel without flat coil defects and color difference defects comprises the following chemical components in percentage by mass:
c: 0.13%, Si: 0.6%, Mn: 2.0%, Alt: 0.07%, Cr: 0.4%, Mo: 0.25%, and the balance of Fe and inevitable impurities.
Example 4
Comparing example 4 with example 1, example 4 differs from example 1 in that:
the model of coil of strip is DP590, and actual thickness is 3mm, and preset thickness is 4mm, judges that the hydraulic pressure of ultrafast cold adopts the second to preset pressure.
The second preset pressure is 0.3 MPa.
The end temperature of the ultra-fast cooling was 600 ℃.
Example 5
Comparing example 5 with example 1, example 5 differs from example 1 in that:
the model of coil of strip is DP590, and actual thickness is 3mm, and preset thickness is 4mm, judges that the hydraulic pressure of ultrafast cold adopts the second to preset pressure.
The second preset pressure is 0.3 MPa.
The final temperature of the ultra-fast cooling was 600 ℃ and the idling time was 40 s.
Comparative example 1
Comparative example 1 and example 1 were compared, and comparative example 1 and example 1 were distinguished in that:
the preset thickness is 4mm, but the hydraulic pressure for judging the ultra-fast cooling adopts a second preset pressure.
The second preset pressure is 0.3 MPa.
The end temperature of the ultra-fast cooling was 600 ℃.
Comparative example 2
Comparative example 2 is compared with example 1, and comparative example 2 differs from example 1 in that:
ultrafast water cooling is not adopted, and the coiling temperature is 630 ℃.
Laminar cooling includes: laminar cooling in sparse cooling mode.
Comparative example 3
Comparative example 3 is compared with example 1, and comparative example 3 differs from example 1 in that:
ultrafast water cooling is not adopted, and the coiling temperature is 580 ℃.
Laminar cooling includes: laminar cooling using a dense cooling mode.
Comparative example 4
Comparative example 4 is compared with example 4, and comparative example 4 differs from example 4 in that:
ultrafast water cooling is not adopted, and the coiling temperature is 630 ℃.
Laminar cooling includes: laminar cooling in sparse cooling mode.
Comparative example 5
Comparative example 5 is compared with example 4, and comparative example 5 differs from example 4 in that:
ultrafast water cooling is not adopted, and the coiling temperature is 580 ℃.
Laminar cooling includes: laminar cooling using a dense cooling mode.
Comparative example 6
Comparative example 6 is compared with example 5, and comparative example 6 differs from example 5 in that:
the time of idling was 20 s.
The storage comprises the following steps: and (4) storing in a double-layer stacking mode.
Comparative example 7
Comparative example 7 and example 5 were compared, and comparative example 7 and example 5 were distinguished in that:
the time of idling was 20 s.
The storage comprises the following steps: and (4) storing in a single-layer stacking mode.
Comparative example 8
Comparative example 8 and example 5 were compared, and comparative example 8 and example 5 differed in that:
no idling is used.
Related experiments:
the steel strips obtained in examples 1 to 5 and comparative examples 1 to 8 were collected and subjected to cold rolling to obtain high-strength automobile sheets, and the performance of each high-strength automobile sheet was tested, and the results are shown in table 1.
Test methods of the related experiments:
inner diameter difference of hot coil: and (4) manually measuring by using a measuring tape, and judging whether the coil diameter meets the standard or not according to the inner diameter difference of the hot coil.
And (3) whether the finished product has color difference: by visual observation.
TABLE 1
| Categories | Inside diameter difference of hot coil (mm) | Whether the roll diameter meets the standard | Whether the finished product has color difference or not |
| Example 1 | 23 | Is that | Is free of |
| Example 2 | 30 | Is that | Is free of |
| Example 3 | 27 | Is that | Is free of |
| Example 4 | 22 | Is that | Is free of |
| Example 5 | 20 | Is that | Is free of |
| Comparative example 1 | 40 | Whether or not | Is free of |
| Comparative example 2 | 28 | Is that | Is provided with |
| Comparative example 3 | 45 | Whether or not | Is free of |
| Comparative example 4 | 30 | Is that | Is provided with |
| Comparative example 5 | 49 | Whether or not | Is free of |
| Comparative example 6 | 30 | Is that | Is free of |
| Comparative example 7 | 30 | Is that | Is free of |
| Comparative example 8 | 38 | Is that | Is free of |
Specific analysis of table 1:
the inner diameter difference of the hot coil is the difference value of the major axis and the minor axis of the ellipse in the hot coil, and when the inner diameter difference of the hot coil is smaller, the metallographic structure of the obtained strip steel is more uniform, and the flat coil defect of the strip steel is also indicated.
From the data of examples 1-5, it can be seen that:
different ultra-fast cooling water pressure pressures are adopted according to the thickness of the steel coil, the inner diameter difference of the obtained hot coil is kept within 25mm, and the final cold-rolled product has no color difference, so that the product quality requirement is met.
From the data of comparative examples 1-8 it can be seen that:
if the water pressure of the ultra-fast cooling is not controlled according to the thickness of the steel coil, the coiling temperature of the steel coil is not controlled, and the idle running time or the idle running time is not adopted in the range of the application, the obtained steel coil has the risk of flat coil defects or surface color difference defects, so that the product quality requirement is not met.
One or more technical solutions in the embodiments of the present application at least have the following technical effects or advantages:
(1) the method provided by the embodiment of the application respectively determines the water pressure of the ultrafast water cooling with the thickness specification of more than 4mm and less than 4mm, and simultaneously determines the coiling temperature of 540 +/-20 ℃, so as to control the cooling speed of the ultrafast water cooling through the water pressure, and the method can control the metallographic structure change of the steel coil by combining the coiling temperature, can generate an even temperature field and internal stress in the cooling process, improve the flat coil defect of the strip steel, simultaneously improve the surface hardness and the anti-cracking capacity of the steel coil, and improve the surface color difference defect of the strip steel.
(2) The steel strip provided by the embodiment of the application has the advantages that the inner diameter difference of a hot coil is below 25mm, and the defects of flat coil and surface color difference are avoided.
(3) The method provided by the embodiment of the application can integrate the control of the water pressure of ultra-fast water cooling, the control of the coiling temperature and the control of the idle time into the automatic production line of the high-strength automobile plate, thereby further shortening the production process and reducing the production consumption.
The drawings illustrate:
FIG. 4 is a schematic illustration of a high-strength automotive sheet produced by a conventional process according to the comparative example of the present application showing a flat coil defect;
FIG. 5 is a schematic view of a high-strength automotive sheet produced by the method of the present application without a flat-roll defect;
as can be seen from FIGS. 4 and 5, when the method provided by the present application is used, the high-strength automobile plate is produced without the flat rolling defect.
FIG. 6 is a schematic diagram showing the distribution of the inner diameter of the hot coil of the high-strength automobile sheet produced by the method of the present application, and it can be known from FIG. 6 and the data in Table 1 that the inner diameter of the hot coil of the high-strength automobile sheet product is uniformly distributed.
FIG. 7 is a schematic view of a high-strength automobile sheet produced by conventional companies according to an embodiment of the present application showing surface color difference defects;
FIG. 8 is a schematic view of a high-strength automobile sheet produced by the method according to the embodiment of the present application without surface color difference defects;
as can be seen from FIGS. 7 and 8, when the method provided by the present application is used, the high-strength automobile sheet is produced without surface color difference defects.
It is noted that, in this document, 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. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
The foregoing are merely exemplary embodiments of the present invention, which enable those skilled in the art to understand or practice the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims (9)
1. A preparation method of a strip steel without flat coil defects and color difference defects is characterized by comprising the following steps:
obtaining a steel coil after finish rolling;
carrying out ultra-fast cooling on the steel coil, and then carrying out air cooling and laminar cooling to obtain a cooled steel coil;
coiling the cooled steel coil, and then idling and unloading to obtain the hot-coiled steel coil;
storing the hot rolled steel coil to obtain strip steel without flat coil defects and color difference defects;
wherein the hydraulic pressure of the ultra-fast cooling is 0.3MPa to 0.9MPa, and the coiling temperature is 520 ℃ to 560 ℃.
2. The method according to claim 1, wherein the ultra-fast cooling is performed on the steel coil, and then air cooling and laminar cooling are performed on the steel coil to obtain a cooled steel coil, and the method specifically comprises the following steps:
respectively obtaining the actual thickness and the preset thickness of the steel coil;
judging whether the water pressure of the ultra-fast cooling is a first preset pressure or a second preset pressure according to the actual thickness and the preset thickness;
if the actual thickness is larger than or equal to the preset thickness, judging that the water pressure of the ultra-fast cooling is a first preset pressure;
if the actual thickness is smaller than the preset thickness, judging that the water pressure of the ultra-fast cooling is a second preset pressure;
and carrying out ultrafast cooling according to the first preset pressure or the second preset pressure, and then carrying out air cooling and laminar cooling to obtain the cooled steel coil.
3. The method according to claim 2, wherein the predetermined thickness is greater than or equal to 4 mm.
4. The method according to claim 2, wherein the first predetermined pressure is 0.5 to 0.9MPa and the second predetermined pressure is 0.3 to 0.7 MPa.
5. The method of claim 1, wherein the ultra-fast cooling end point temperature is 580 ℃ to 620 ℃; the idling time is 40-60 s.
6. The method of claim 1, wherein the laminar cooling comprises: laminar cooling in a dense cooling mode;
the storing comprises: and (4) storing in a single-layer stacking mode.
7. A steel strip free of edge roll defects and color cast defects, said strip being produced by the method of any one of claims 1 to 6.
8. The steel strip of claim 7 having a chemical composition, in mass fraction, comprising:
c: 0.05 to 0.13 percent, Si: 0.03 to 0.6 percent, Mn: 1.0-2.0%, P is less than or equal to 0.03%, S is less than or equal to 0.07%, Alt: 0.03 to 0.07 percent of Cr: 0.1% -0.4%, Mo: 0.15 to 0.25 percent, and the balance of Fe and inevitable impurities.
9. Use of a steel strip according to any one of claims 7 to 8 in the production of high-strength motor vehicle panels.
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Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201760452U (en) * | 2010-08-06 | 2011-03-16 | 攀钢集团钢铁钒钛股份有限公司 | Ultrafast cooling system for hot tandem rolling strip steel and medium plate production lines |
| CN202638905U (en) * | 2012-06-21 | 2013-01-02 | 攀钢集团攀枝花钢钒有限公司 | Arrangement structure of ultrafast cooling system nozzle for hot continuous rolling steel plate |
| CN104694719A (en) * | 2015-03-12 | 2015-06-10 | 攀钢集团西昌钢钒有限公司 | Thick-specification pipeline steel cooling method |
| DE202015104565U1 (en) * | 2015-08-27 | 2015-09-15 | Northeastern University | Cooling and spraying water system for medium thick sheet after rolling |
| CN106086638A (en) * | 2016-06-17 | 2016-11-09 | 首钢总公司 | A kind of Galvanized Dual Phase Steel and production method thereof |
| CN107442585A (en) * | 2017-07-27 | 2017-12-08 | 江苏省沙钢钢铁研究院有限公司 | Control method for realizing special cooling of starting end of hot-rolled strip steel |
| CN111607736A (en) * | 2020-06-28 | 2020-09-01 | 武汉钢铁有限公司 | Wear-resistant steel with excellent welding performance and production method thereof |
| CN113073251A (en) * | 2021-03-25 | 2021-07-06 | 山东钢铁集团日照有限公司 | Manufacturing method of 590 MPa-grade hot-rolled complex phase steel for thick-specification high-fatigue-performance automobile spoke |
-
2021
- 2021-12-03 CN CN202111472414.0A patent/CN114369707B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201760452U (en) * | 2010-08-06 | 2011-03-16 | 攀钢集团钢铁钒钛股份有限公司 | Ultrafast cooling system for hot tandem rolling strip steel and medium plate production lines |
| CN202638905U (en) * | 2012-06-21 | 2013-01-02 | 攀钢集团攀枝花钢钒有限公司 | Arrangement structure of ultrafast cooling system nozzle for hot continuous rolling steel plate |
| CN104694719A (en) * | 2015-03-12 | 2015-06-10 | 攀钢集团西昌钢钒有限公司 | Thick-specification pipeline steel cooling method |
| DE202015104565U1 (en) * | 2015-08-27 | 2015-09-15 | Northeastern University | Cooling and spraying water system for medium thick sheet after rolling |
| CN106086638A (en) * | 2016-06-17 | 2016-11-09 | 首钢总公司 | A kind of Galvanized Dual Phase Steel and production method thereof |
| CN107442585A (en) * | 2017-07-27 | 2017-12-08 | 江苏省沙钢钢铁研究院有限公司 | Control method for realizing special cooling of starting end of hot-rolled strip steel |
| CN111607736A (en) * | 2020-06-28 | 2020-09-01 | 武汉钢铁有限公司 | Wear-resistant steel with excellent welding performance and production method thereof |
| CN113073251A (en) * | 2021-03-25 | 2021-07-06 | 山东钢铁集团日照有限公司 | Manufacturing method of 590 MPa-grade hot-rolled complex phase steel for thick-specification high-fatigue-performance automobile spoke |
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