CN112853221A - Chromium plating plate for easy-open end and processing method thereof - Google Patents
Chromium plating plate for easy-open end and processing method thereof Download PDFInfo
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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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- B—PERFORMING OPERATIONS; TRANSPORTING
- B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
- B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES, OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
- B21C37/00—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape
- B21C37/02—Manufacture of metal sheets, bars, wire, tubes or like semi-manufactured products, not otherwise provided for; Manufacture of tubes of special shape of sheets
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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
- 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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0226—Hot rolling
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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
- C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
- C21D8/0236—Cold rolling
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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
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
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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
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/20—Ferrous alloys, e.g. steel alloys containing chromium with copper
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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
- C22C38/26—Ferrous alloys, e.g. steel alloys containing chromium with niobium or tantalum
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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
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
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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
- C22C38/32—Ferrous alloys, e.g. steel alloys containing chromium with boron
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D3/00—Electroplating: Baths therefor
- C25D3/02—Electroplating: Baths therefor from solutions
- C25D3/04—Electroplating: Baths therefor from solutions of chromium
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- C—CHEMISTRY; METALLURGY
- C25—ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
- C25D—PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
- C25D7/00—Electroplating characterised by the article coated
Abstract
The invention discloses a chromium plating plate for an easy-open end and a processing method thereof, wherein the chromium plating plate comprises one or more of the following six components in percentage by mass: b: 0.0001 to 0.0005 percent, Cr: 0.0015-0.02%, Ti: 0.002-0.01%, Nb: 0.002-0.008%, Cu: 0.002-0.03%, Mo: 0.001% -0.008%; and C: 0.02 to 0.06%, Mn: 0.2-0.4%, Al: 0.01-0.08%, N:0 to 0.004 percent; and the balance of Fe and inevitable impurities. The processing method comprises the following process steps: converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling, continuous annealing, secondary cold rolling and chromium plating treatment; wherein the reduction rate is controlled to be 11-14%, the rolling tension is 60-100MPa, the intermediate tension is controlled during rolling, the elongation difference of the rolling direction RD, the 45-degree direction and the vertical direction TD is reduced, and the elongation in the three directions is controlled to be more than or equal to 8%.
Description
Technical Field
The invention belongs to the field of packaging steel, and particularly relates to a chromium-plated raw plate for an easy-open cover and a processing method thereof, in particular to a high-strength chromium-plated raw plate for the easy-open cover, a screwed cover and the like and a manufacturing method thereof.
Background
Steel for packaging generally refers to a type of steel used for producing various cans and lids for food, beverages, chemical industry, generally having a thickness of less than 0.5 mm. Due to its superior sheet properties, it is often used in the production of various cans (e.g., two-piece beverage cans, three-piece beverage cans, powdered milk cans, three-piece food cans, etc.) and various lids (e.g., crown caps, twist-off caps, easy-open caps, etc.). Based on the requirements of energy conservation, emission reduction, cost reduction and consumption reduction, the strength requirement of the steel for packaging is continuously improved.
The processing performance of the chromium plating plate in the iron printing coating is obviously superior to that of chromium plating iron. With the wide use of the coating iron, particularly in the aspect of covers, the chromium plating plate is more emphasized by people, and the chromium plating plate has the characteristics that: the can making processing and the corrosion resistance of the base plate are the same as those of the base plate of the tinplate; in the coating processing, the tin melting problem of tinplate does not need to be considered, and higher baking temperature can be adopted to improve the printing and coating production efficiency; the adhesive force to the coating is superior to that of tinplate; the surface of the tin-iron alloy is provided with an extremely thin metal chromium layer and a hydrated chromium oxide layer, and the thickness of the chromium-iron alloy is only about 1 percent of that of the tin-iron layer. Because the tin-free thin plate is adopted, the tin resource is saved, and the development direction of the tin plate is met.
On the other hand, the secondary cold rolling strengthening method is that the steel plate is subjected to smelting, continuous casting, hot rolling, pickling, cold rolling and continuous annealing and then subjected to secondary cold rolling, the secondary cold rolling (DCR) is widely applied to the manufacturing of chromium-plated plates at present, and compared with the chromium-plated plates obtained by the primary cold rolling (SCR) method, the chromium-plated plates obtained by the DCR have higher strength and thinner thickness, so that the reduction of the thickness of food, beverage, chemical industry tank and cover materials and the reduction of the cost can be effectively realized.
However, the DCR method tends to result in lower elongation of the steel sheet, particularly in the 45 ° direction and the perpendicular direction TD, compared to the SCR. When the method is used for producing parts with high requirements on the elongation in all directions, such as easy-open ends and standard ends, surface painting and baking treatment are needed before punching forming (baking temperature is about 200 ℃ and time is 10-30 min), so that the elongation in all directions of the substrate is further reduced due to baking hardening, the easy-open ends and the standard ends are easy to crack in the direction with the lowest elongation of the substrate, the conventional easy-open end manufacturers require the elongation in three directions to be not less than 8% to reduce punching cracking, the yield strength is not less than 480MPa to improve the pressure resistance, and the method is convenient for filling of gas-containing beverages and the like.
The relevant DCR methods disclosed at home and abroad at present are as follows:
U.S. patent publication No. US7501031B2 discloses a pharmaceutical composition comprising, by mass percent, C: 0.003-0.005 percent of Si, less than or equal to 0.04 percent of Mn, less than or equal to 0.6 percent of Mn, P: 0.005-0.03 percent of steel grade, less than or equal to 0.02 percent of S, more than or equal to 0.005-0.1 percent of Al and less than or equal to 0.005 percent of N, the steel grade is suitable for SCR and DCR methods, different steel plates with the hardness of 61 +/-3 to 76 +/-3 (HR30T) can be obtained, and the smaller delta r is ensured.
Chinese patent publication No. CN102234736A discloses a method for manufacturing a high-strength, excellent isotropic secondary cold-rolled tin-plated raw sheet, comprising the steps of: c: 0.02-0.06%, less than or equal to 0.03% of Si, 0.10-0.30% of Mn, less than or equal to 0.015% of P, less than or equal to 0.015% of S, Al: 0.03-0.10 percent of low-carbon steel with N less than or equal to 0.0035 percent is subjected to hot rolling control: the heating temperature is less than or equal to 1180 ℃, the finish rolling temperature is more than Ar3, the coiling temperature is 620-750 ℃, and the primary cold rolling control: the reduction rate is 75-90%, and the continuous annealing control: annealing temperature: 640-700 ℃, annealing time of 50-150 s, secondary cold rolling control: the reduction rate is 15-35%, and the DCR tinning raw plate with HR30T 60-80 and the earing rate less than or equal to 5% is obtained.
The secondary cold rolling ratio of the above patent technologies is large, which tends to increase the anisotropy of the final steel sheet and to greatly reduce the elongation in the transverse direction.
Chinese patent publication No. CN101649381A discloses a method for producing DCR tin plating raw plates, which controls one-time cold rolling of a low-carbon steel: the rolling rate is 85-90%, and the cover annealing control: annealing temperature is 510-560 ℃, and secondary cold rolling control: the rolling rate is 30-40%, and the steel plate with the advantages of thin thickness, high hardness, good corrosion resistance, good deep drawing processability and the like is obtained. Wherein, the cover annealing often obtains the cooperation of lower intensity and higher elongation, and the patent technology secondary cold rolling section reduction rate is big.
Further, patent document No. WO2008/018531a1 discloses a method for producing a DCR tin plating raw sheet, comprising the steps of mixing a component C: 0.02-0.06%, Si is less than or equal to 0.03%, Mn: 0.05-0.5%, P is less than or equal to 0.02%, S is less than or equal to 0.02%, Al: 0.02-0.1%, N: and (3) carrying out production control on 0.008-0.015% of low-carbon steel: the heating temperature is more than or equal to 1200 ℃, the coiling temperature is less than or equal to 600 ℃, the primary cold rolling reduction rate is more than or equal to 80%, and the secondary cold rolling reduction rate is 6-15%, so that the DCR plate with the RD direction elongation rate of 10% and the TD direction elongation rate of more than 5% is obtained.
U.S. Pat. No. US7169243B2 discloses a correspondence equation between the tensile strength Rm and the rolling elongation a% of a DCR material obtained at a cooling rate of 100 ℃/s or more in the continuous annealing stage: (640-Rm)/10 is more than or equal to A percent and is more than or equal to 700-Rm)/11.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a chromium plating plate for an easy-open end and a processing method thereof, and the chromium plating plate obtained by the method can ensure that the steel plate still has higher yield strength and elongation in three directions of RD, 45 degrees and TD after being baked under the condition of lower alloy content, so that the chromium plating plate is suitable for processing and forming parts such as the easy-open end, a standard end and the like.
The technical problem to be solved can be implemented by the following technical scheme.
The chromium plating plate for the easy-open end is characterized by comprising one or more of the following six components in percentage by mass:
B：0.0001％～0.0005％，Cr：0.0015～0.02％，Ti：0.002～0.01％，Nb：0.002～0.008％，Cu：0.002～0.03％，Mo：0.001％～0.008％；
and the combination of (a) and (b),
c: 0.02 to 0.06%, Mn: 0.2-0.4%, Al: 0.01-0.08%, N:0 to 0.004% (excluding 0);
and the balance of Fe and inevitable impurities.
As a preferred form of the present invention, B: 0.0002 to 0.0004%, Ti: 0.002-0.008%, Nb: 0.006-0.008%, Mo: 0.002-0.006%.
The chromium-plated plate is prepared by the following process steps:
converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling, continuous annealing, secondary cold rolling and chromium plating treatment;
in the process steps, the continuous annealing temperature is 720-740 ℃; the speed of the unit is more than or equal to 480 mpm; the secondary cold rolling is mainly carried out in a rolling mode, the secondary cold rolling tension is 60-100MPa, the intermediate tension is controlled, and the secondary cold rolling reduction rate is controlled to be 11-14%.
In the composition design of the steel of the invention:
the element C is solid-dissolved in the material in the form of interstitial atoms or precipitated in a matrix in the form of cementite, and plays a role in improving the yield strength of the steel plate by solid-solution strengthening and precipitation strengthening on the steel plate, but the plasticity is easily reduced due to the excessively high content of C, and the final processing performance and isotropy of the product, especially the anti-aging performance of the material are adversely affected, so that the content of C in the chromium-plated plate is controlled between 0.02 and 065 percent.
Mn is a strengthening element and desulfurization in steel, but too high content is unfavorable for the punching processability of the material. The Mn content of the steel is controlled to be 0.2-0.4%.
The Al element mainly plays a role of a deoxidizer in the steel, and simultaneously the N element and the Al in the steel form AlN precipitation to eliminate the influence of the N element on the aging performance of the steel, so that the Al content of the steel is controlled to be 0.01-0.08%;
the solid solution of the N element can greatly improve the strength of the steel, and meanwhile, the ageing property of the steel is poor and the isotropy of the steel is influenced due to too high N content, so that the N content of the steel is controlled to be below 0.004 percent.
Wherein, the chrome plating raw plate comprises the following components: b: 0.0001 to 0.0005 percent, Cr: 0.0015-0.02%, Ti: 0.002-0.01%, Nb: 0.002-0.008%, Cu: 0.002-0.03%, Mo: 0.001-0.008% of one or more of the components in percentage by mass. Wherein, the addition of B element further reduces the loss of elongation percentage during the baking aging of the steel plate, and the addition of Cr, Ti, Nb, Cu and Mo all play the role of further improving the strength of the steel plate. According to the specific requirements of strength and elongation after baking and aging in practical application, the components can be added to finely adjust the performance of the steel plate.
Another technical problem to be solved by the present invention is to provide a method for processing the chromium plating plate for easy-open end, comprising the following steps:
converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling, continuous annealing and secondary cold rolling;
wherein the secondary cold rolling reduction rate is controlled to be 11-14%, the rolling tension is 60-100MPa, the intermediate tension is controlled during rolling, the elongation difference of the rolling direction RD, the 45-degree direction and the vertical direction TD is reduced, and the elongation in the three directions is controlled to be more than or equal to 8%.
As a further improvement of the technical scheme, the chromium plating treatment is needed after the secondary cold rolling, and during the treatment, the single-side metal chromium content of the plating layers on the upper surface and the lower surface is controlled to be more than or equal to 50mg/m2The single chromium oxide layer is more than or equal to 5mg/m2。
Wherein, the tension in the secondary cold rolling mainly plays a role in controlling the shape of the rolled steel plate. Generally, the tension of the secondary cold rolling is 110-150 MPa. The larger tension corresponds to tensile deformation of the steel sheet in one rolling direction, so that the anisotropy of the steel sheet is often further improved, and particularly the anisotropy of the steel sheet after secondary baking aging of the cold-rolled steel sheet is obviously influenced: the higher the tension is, the more obvious the elongation rate is reduced in the direction vertical to the rolling direction after baking; and the tension is too small to ensure the good shape of the steel strip, so that the secondary cold rolling is mainly performed in a rolling mode, the tension of the secondary cold rolling is 60-100MPa, the intermediate tension is controlled, and the elongation difference in three directions is reduced.
Secondary cold rolling is often used to increase the yield strength of the steel sheet. Generally, the reduction rate of secondary cold rolling is more than 15%, at the moment, the structure is rolled into a strip shape, higher dislocation density exists in crystal grains, mutual cutting of dislocations is intensified during movement, resistance is increased, deformation resistance is increased, plastic deformation is difficult, the strength of a steel plate is improved, and the elongation is reduced; the increase in the secondary cold rolling reduction particularly increases the anisotropy of the steel sheet, and the elongation in the direction perpendicular to the rolling direction is rapidly deteriorated. Therefore, in order to ensure that the steel plate is strengthened and a certain elongation in all directions, the secondary cold rolling reduction rate in the secondary cold rolling method is controlled within the range of 11-14%.
According to the secondary cold rolling method, on one hand, the deformation of the steel plate is adopted to further improve the yield strength of the steel plate, but the reduction rate is controlled in a lower range, so that the problem that the elongation rate of the steel plate is reduced when the reduction rate is too large is solved; the control of the tension in the secondary cold rolling method is a great innovation of the invention, and the transverse elongation of the steel plate can be greatly reduced after the steel plate is baked and aged with too high tension. When the tension is 60-100MPa, the secondary cold rolling reduction rate of 11-14% is combined, so that the secondary cold rolling method can be ensured to improve the yield strength of the steel plate, but the elongation rate of the steel plate, especially the transverse elongation rate, is not weakened.
Based on the combination of the two key technologies, the chromium plating raw plate structure is finally obtained by adding the strip-shaped distributed cementite particles without solid solution into ferrite. After the chromium-plated original plate is finally baked and hardened, the yield strength RP0.2 is more than or equal to 480MPa, and the elongation rates in the rolling direction RD, the 45-degree direction and the vertical direction TD are more than or equal to 8%.
As a further improvement of the technical scheme, the hot rolling conditions before the secondary cold rolling of the chromium-plated raw plate are as follows: the slab is heated to be more than or equal to 1200 ℃, the finishing temperature is more than or equal to 840 ℃, and the coiling temperature is less than or equal to 650 ℃.
As a further improvement of the technical scheme, the reduction rate of the primary cold rolling before the secondary cold rolling of the chromium-plated raw plate is 85-90%.
And also as a further improvement of the technical scheme, in the continuous annealing step before the secondary cold rolling of the chromium-plated raw plate, the annealing temperature is 720-740 ℃, the cooling rate is more than 80 ℃/s, the speed of a machine set is more than or equal to 480mpm, the induction heating of an RH section is not used, the over-aging OA section is not required, and the annealing is cooled along with the furnace.
In a preferred embodiment of the method, the secondary cold rolling is mainly performed in a rolling mode, the secondary cold rolling tension is 60 to 100MPa, the intermediate tension is controlled, and the secondary cold rolling reduction is controlled to be 11 to 14%. Preferably, the secondary cold rolling tension: 70-90 MPa, reduction rate: 12 to 14 percent.
The steel of the invention is prepared by the following steps:
in the hot rolling process, the austenite in the steel cannot be completely recrystallized due to too low heating temperature, so that the refinement of crystal grains after hot rolling is influenced; C. the N element cannot be effectively dissolved in the solution, the yield strength of the steel after the final secondary cold rolling can be influenced, and the invention is suitable for the steel hot rolling heating temperature of more than or equal to 1120 ℃.
The hot rolling finishing temperature is too low, so that the steel enters a ferrite and austenite two-phase region for rolling, the finish rolling crystal grains are easy to be uneven, and the performance uniformity of the steel plate after secondary cold rolling is finally influenced, and the invention is suitable for the steel hot rolling finishing temperature being more than or equal to 840 ℃; the hot rolling coiling temperature is too high, so that carbides aggregate to grow or form a coarse pearlite structure, the strength of the final secondary cold rolled steel is reduced, and the hot rolling coiling temperature of the steel is less than or equal to 650 ℃.
The first cold rolling is carried out after the hot rolling, the yield strength of the final secondary cold rolled steel is low due to the low selected cold rolling reduction rate, the isotropy is unfavorable due to the overhigh rolling reduction rate, the equipment requirement is higher, and the range of the one-time cold rolling reduction rate of the steel suitable for the invention is 85-90%; annealing after cold rolling is a stage of effectively eliminating internal stress in the steel, adjusting the isotropy of the steel and promoting the recrystallization of crystal grains in the steel. Too low annealing temperature results in insufficient recrystallization, affecting the isotropy of the steel. The method is suitable for continuous annealing of steel at the temperature of 720-740 ℃, the cooling rate is more than 80 ℃/s, the speed of a unit is more than or equal to 480mpm, induction heating of an RH section is not used, an OA section is not required during overaging, and furnace cooling is carried out. The method has the advantages that the grains are refined on the basis of ensuring full recrystallization, the strength of the annealed material is improved, meanwhile, the excellent toughness of the material is ensured, and a larger margin is left for secondary cold rolling.
Compared with the prior art, the invention has the following beneficial effects:
compared with the ultra-low carbon steel disclosed in the US patent 7501031B2, the alloy components of the steel disclosed in the invention are very different from each other, especially the content of C is one order of magnitude higher, and as an enhancing element in steel, the difference of C inevitably causes the great difference of yield strength of two steels in the same process, and the ultra-low carbon steel disclosed in the invention has strict requirements on steel making and inclusion control, the steel making cost of the components of the invention is low, and the inclusion is easy to control.
Compared with the requirement of Chinese patent document CN102234736A on large secondary cold rolling rate, the alloy components of the invention are also greatly different, and the reduction rate of the secondary cold rolling method disclosed by the invention is obviously smaller than that of the above patent, so that the energy consumption of low rolling tension is lower. Such a large secondary cold rolling ratio tends to result in a final steel sheet having a large anisotropy, and a large decrease in elongation in the transverse direction.
Compared with the continuous annealing process adopting hood-type annealing in Chinese patent document CN101649381A, the invention discloses that continuous annealing is adopted in the annealing section of a chromium-plated original plate, which is fundamentally different from the hood-type annealing method of the above patent for obtaining a steel plate: the hood-type annealing is often matched with lower strength and higher elongation, and the continuous annealing is higher in strength and lower in elongation. And the reduction rate of the secondary cold rolling section is greatly different. The steel plate obtained by adopting the continuous annealing process has stronger performance stability and lower energy consumption and cost.
The three patent documents are different from the final performance indexes of the steel plate obtained by the invention, and the patent documents do not meet the requirement of ensuring the high elongation in all directions after the baking and aging.
Compared with the patent document WO2008/018531A1, the invention discloses that the alloy composition of the chromium-plated raw plate is greatly different from the above patent. The elongation in TD direction of the chromium-plated original plate can still be kept more than 8% after baking and hardening, and the performance is better. The invention controls the following rate of the secondary cold rolling: 11-14%, and the rolling tension range is also controlled: 60-100MPa, the yield strength RP0.2 of the obtained chromium-plated raw plate after baking and hardening is more than or equal to 480MPa, and the elongation rates in the rolling direction RD, the 45-degree direction and the vertical direction TD are more than or equal to 8 percent, so that the chromium-plated raw plate has more excellent performance than the chromium-plated raw plate.
Compared with the method disclosed in the U.S. Pat. No. 4, 7169243, 2, the method adopted by the invention is completely different, and the high-cooling-rate annealing method disclosed in the U.S. Pat. No. 4,893 has high equipment requirement, and easily causes the problem of poor plate shape in the production of thin plates, thus being not beneficial to producing wide-specification tin-plated raw plates. The temperature of the continuous annealing section of the chromium-plated raw plate is 700-740 ℃, and the cooling section cools according to the running speed of a conventional machine set, and the method is completely different from the production method.
Detailed Description
The invention discloses a chromium plating plate for an easy-open end, which comprises the following components in percentage by mass: c: 0.02 to 0.06%, Mn: 0.2-0.4%, Al: 0.01-0.08%, N: less than or equal to 0.004 percent, and the balance of Fe and inevitable impurities; the original plate needs to be subjected to secondary cold rolling, the secondary cold rolling is mainly carried out in a rolling mode, the rolling tension is 60-100MPa, the intermediate tension is controlled, and the reduction rate of the secondary cold rolling is controlled to be 11-14%. The plate needs to be processed by chrome plating, the amount of metal chromium plated on the upper surface and the lower surface (single surface) is more than or equal to 50mg/m2The chromium oxide layer (single layer) is not less than 5mg/m2。
The chromium-plated plate comprises the following components in percentage by mass: b: 0.001-0.005%, Cr: 0.001-0.02%, Ti: 0.001 to 0.01%, Nb: 0.001-0.01%, Cu: 0.001-0.03% and Mo: 0.001-0.008% of one or more than one component.
After the chromium-plated plate is baked and hardened, the yield strength RP0.2 is more than or equal to 480MPa, and the elongation rates in the three directions of the rolling direction RD, the 45-degree direction and the vertical direction TD are more than or equal to 8%. The microstructure of the chromium plating raw plate is ferrite and zonally distributed granular cementite.
The production steps of the chrome-plated original plate before the secondary cold rolling are as follows: converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling and continuous annealing.
The hot rolling steps before the secondary cold rolling of the steel plate are as follows: the slab is heated to be more than or equal to 1200 ℃, the finishing temperature is more than or equal to 840 ℃, and the coiling temperature is less than or equal to 650 ℃.
The reduction rate of the primary cold rolling before the secondary cold rolling of the chromium-plated original plate is 85-90%.
In the continuous annealing step before the secondary cold rolling of the chromium-plated raw plate, the annealing temperature is 720-740 ℃.
The chromium plating plate is suitable for processing and forming parts such as an easy-open cover, a standard cover and the like.
The following is a more detailed description of the present invention with reference to specific examples.
The embodiment shows that the yield strength of the chromium-plated plate after baking and aging can be ensured to be more than or equal to 480MPa and the three-dimensional elongation can be more than or equal to 8 percent by controlling the heating temperature of the plate blank to be more than or equal to 1200 ℃, the finish rolling temperature to be more than or equal to 840 ℃, the coiling temperature to be less than or equal to 650 ℃, and controlling the secondary cold rolling tension to be 60-100MPa and combining the secondary cold rolling reduction rate of 12-14 percent. The material of the comparative example, though having a relatively high strength, has a lower elongation than that required for a cold-rolled sheet for an easy-open end, and particularly has a lower elongation in the 90 ° direction, and is likely to cause cracking during foaming and riveting of the easy-open end, resulting in product failure.
Wherein, the roller diameter of 410-460 mm is adopted in the secondary cold rolling.
In the tables below, table 1 shows the alloy compositions of the examples of the present invention and the comparative examples.
Table 2 shows the process of the steel sheets before the secondary cold rolling in each example of the present invention and comparative example.
Table 3 shows the properties after bake hardening of steel sheets obtained by the secondary cold rolling at different reduction ratios in examples of the present invention and comparative examples.
It can be seen from comparative examples 1, 2 and 3 that, in the composition range, when the annealing temperature is 670 ℃, the continuous annealing speed is equivalent to that of the example, the strength is slightly improved, but the elongation is obviously reduced, and the TD direction can not meet the requirement of normal cap making. When the rolling tension is increased to 120MPa and 140MPa, the larger tension is equivalent to tensile deformation in one rolling direction of the steel plate, so that the anisotropy of the steel plate is often further improved, and particularly the anisotropy of the steel plate after secondary baking and aging of the cold-rolled steel plate is obviously influenced.
From example 14 and comparative examples 4 and 5, it is understood that, in the composition range, when the annealing temperature is 735 ℃, the elongation of the material is gradually reduced and the anisotropy is increased when the rolling tension is increased from 80MPa to 120MPa and 140MPa, and the elongation of the material is significantly reduced when the rolling tension is gradually increased, particularly to 140 MPa. Comparative examples 4 and 5 have significantly better overall elongation than comparative examples 1, 2 and 3, in which the annealing temperature is 670 ℃, but significantly lower than in the examples. The high-temperature annealing and the rapid cooling can effectively improve the strength of the material and can not obviously reduce the elongation of the material.
The tension in the secondary cold rolling mainly acts to control the shape of the steel sheet. The large tension is equivalent to the tensile deformation of the steel plate in one rolling direction, the anisotropy of the steel plate can be further improved, particularly the anisotropy of the steel plate after the secondary cold-rolled steel plate is baked and aged, and the tension is too small to ensure the good strip shape, so that the strip shape can be effectively ensured by the rolling tension of 60-100MPa, and the influence on the elongation of the material is small.
Table 1 units: mass percent
| C | Mn | Al | N | B | Cr | Cu | Mo | Ti | Nb | |
| Example 1 | 0.039 | 0.25 | 0.05 | 0.0021 | 0.0001 | 0.0016 | 0.013 | 0.002 | 0 | 0.006 |
| Example 2 | 0.035 | 0.2 | 0.01 | 0.0025 | 0.0002 | 0.0018 | 0.009 | 0.001 | 0.003 | 0.008 |
| Example 3 | 0.042 | 0.26 | 0.06 | 0.0021 | 0.0001 | 0.0016 | 0.008 | 0 | 0.005 | 0.003 |
| Example 4 | 0.043 | 0.30 | 0.03 | 0.0031 | 0 | 0.0016 | 0 | 0.002 | 0.002 | 0.005 |
| Example 5 | 0.036 | 0.28 | 0.02 | 0.0028 | 0.0001 | 0 | 0.010 | 0.005 | 0.004 | 0.002 |
| Example 6 | 0.048 | 0.31 | 0.05 | 0.0033 | 0.0001 | 0.0016 | 0 | 0.002 | 0.003 | 0 |
| Example 7 | 0.026 | 0.33 | 0.04 | 0.0035 | 0 | 0.016 | 0.007 | 0.007 | 0 | 0.004 |
| Example 8 | 0.052 | 0.22 | 0.07 | 0.0038 | 0.0004 | 0 | 0.002 | 0 | 0.002 | 0.006 |
| Example 9 | 0.02 | 0.4 | 0.05 | 0.0018 | 0.0003 | 0.018 | 0.0265 | 0.004 | 0.006 | 0.005 |
| Example 10 | 0.028 | 0.35 | 0.04 | 0.0027 | 0.0003 | 0.014 | 0.028 | 0.006 | 0 | 0 |
| Example 11 | 0.045 | 0.34 | 0.06 | 0.0035 | 0.0005 | 0 | 0 | 0 | 0 | 0 |
| Example 12 | 0.06 | 0.38 | 0.04 | 0.0040 | 0 | 0 | 0 | 0 | 0.01 | 0.008 |
| Example 13 | 0.054 | 0.31 | 0.05 | 0.0029 | 0.0004 | 0 | 0 | 0 | 0.008 | 0.006 |
| Example 14 | 0.036 | 0.28 | 0.02 | 0.0028 | 0.0001 | 0 | 0.010 | 0.005 | 0.004 | 0.002 |
| Comparative example 1 | 0.05 | 0.40 | 0.07 | 0.0038 | 0 | 0.001 | 0.006 | 0 | 0.006 | 0.003 |
| Comparative example 2 | 0.048 | 0.35 | 0.05 | 0.0035 | 0 | 0.0012 | 0.004 | 0 | 0.003 | 0.005 |
| Comparative example 3 | 0.055 | 0.38 | 0.06 | 0.003 | 0 | 0.0009 | 0.008 | 0 | 0 | 0 |
| Comparative example 4 | 0.048 | 0.31 | 0.05 | 0.0033 | 0.0001 | 0.0016 | 0 | 0.002 | 0.003 | 0 |
| Comparative example 5 | 0.026 | 0.33 | 0.04 | 0.0035 | 0 | 0.016 | 0.007 | 0.007 | 0 | 0.004 |
TABLE 2
TABLE 3
Note: and (3) keeping the temperature of the steel plate obtained by the secondary cold rolling for 20min at 200 ℃, then carrying out baking hardening, and then measuring the mechanical property according to a processing tensile sample of JIS5, wherein Rp0.2 is the stress value which generates 0.2% of residual deformation and is taken as the yield strength value, A% is the elongation at break, and the measuring gauge length is 50 mm.
Claims (10)
1. The chromium-plated plate for the easy-open end is characterized by comprising one or more of the following six components in percentage by mass:
B：0.0001％～0.0005％，Cr：0.0015～0.02％，Ti：0.002～0.01％，Nb：0.002～0.008％，Cu：0.002～0.03％，Mo：0.001％～0.008％；
and the combination of (a) and (b),
C：0.02～0.06％，Mn：0.2～0.4％，Al：0.01～0.08％，N：0～0.004％；
and the balance of Fe and inevitable impurities.
2. The chromium plating plate for easy open end of claim 1, wherein in the composition, B: 0.0002 to 0.0004%, Ti: 0.002-0.008%, Nb: 0.006-0.008%, Mo: 0.002-0.006%.
3. The chromium-plated sheet for easy-open end according to claim 1 or 2, which is prepared by the following process steps:
converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling, continuous annealing, secondary cold rolling and chromium plating treatment;
in the process steps, the continuous annealing temperature is 720-740 ℃; the speed of the unit is more than or equal to 480 mpm; the secondary cold rolling is mainly carried out in a rolling mode, the secondary cold rolling tension is 60-100MPa, the intermediate tension is controlled, and the secondary cold rolling reduction rate is controlled to be 11-14%.
4. A method for processing a chromium-plated sheet for easy-open ends as claimed in claim 1 or 2, comprising the following process steps:
converter steelmaking, continuous casting blank, hot rolling, acid pickling, primary cold rolling, continuous annealing, secondary cold rolling and chromium plating treatment;
the method is characterized in that the secondary cold rolling reduction rate is controlled to be 11-14%, the rolling tension is 60-100MPa, the intermediate tension is controlled during rolling, the elongation difference of the rolling direction RD, the 45-degree direction and the vertical direction TD is reduced, and the elongation in the three directions is controlled to be more than or equal to 8%.
5. The method for processing a chromium-plated sheet for easy-open ends as claimed in claim 4, wherein the amount of chromium metal on one side of the plating layers on the upper and lower surfaces is controlled to be not less than 50mg/m during the chromium plating treatment2The single chromium oxide layer is more than or equal to 5mg/m2。
6. The method of processing a chromium plating sheet for easy open end as set forth in claim 4, wherein the hot rolling conditions before the secondary cold rolling of the chromium plating raw sheet are: the slab is heated to be more than or equal to 1200 ℃, the finishing temperature is more than or equal to 840 ℃, and the coiling temperature is less than or equal to 650 ℃.
7. The method for processing a chromium-plated sheet for easy-open ends as claimed in claim 4, wherein the reduction ratio of the primary cold rolling before the secondary cold rolling of the chromium-plated raw sheet is 85% to 90%.
8. The method for processing the chromium-plated sheet for the easy-open end according to claim 4, wherein in the continuous annealing step before the secondary cold rolling of the chromium-plated raw sheet, the annealing temperature is 720-740 ℃, the speed of a machine set is not less than 480mpm, the induction heating at the RH section is not used, the over-aging OA section is not required, and the sheet is cooled along with the furnace.
9. The method for processing a chromium-plated sheet for easy-open ends as claimed in claim 4, wherein the secondary cold rolling is mainly performed in a rolling manner, the secondary cold rolling tension is 60 to 100MPa, the intermediate tension is controlled, and the secondary cold rolling reduction is controlled to 11 to 14%.
10. The method for processing the chromium-plated sheet for easy-open ends as claimed in claim 9, wherein the secondary cold rolling tension is 70 to 90MPa and the reduction rate is controlled to 12 to 14%.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105838994A (en) * | 2016-04-26 | 2016-08-10 | 江苏省沙钢钢铁研究院有限公司 | Chrome-plated board, manufacturing method thereof and crown cap |
| CN106086643A (en) * | 2016-06-23 | 2016-11-09 | 宝山钢铁股份有限公司 | The uncoated tinplate base of a kind of high-strength high-elongation and secondary cold-rolling method thereof |
| CN107234132A (en) * | 2016-03-28 | 2017-10-10 | 宝山钢铁股份有限公司 | The production method of high corrosion-resistant secondary cold-rolling chromium plating steel plate |
-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107234132A (en) * | 2016-03-28 | 2017-10-10 | 宝山钢铁股份有限公司 | The production method of high corrosion-resistant secondary cold-rolling chromium plating steel plate |
| CN105838994A (en) * | 2016-04-26 | 2016-08-10 | 江苏省沙钢钢铁研究院有限公司 | Chrome-plated board, manufacturing method thereof and crown cap |
| CN106086643A (en) * | 2016-06-23 | 2016-11-09 | 宝山钢铁股份有限公司 | The uncoated tinplate base of a kind of high-strength high-elongation and secondary cold-rolling method thereof |
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