JP2018168395A - Manufacturing method of steel plate for easy open can lid - Google Patents

Abstract

A method for producing a steel plate for an easy open can lid having an excellent cut shape is provided. SOLUTION: In mass%, C: 0.010% or more, Si: 0.2% or less, Mn: 0.10% or more and 0.60% or less, P: 0.003% or more and 0.150% or less, S: 0.020% or less, Al: 0.01% or more and 0.06% or less, N: 0.02% or less, and Sn content in the central portion of the plate thickness is 0.001% or more and 0.100 %, And the remainder is annealed at an annealing temperature of 650 ° C. or higher with respect to a cold-rolled steel sheet having a component composition consisting of Fe and inevitable impurities, and then the residence time in the temperature range of 400 ° C. to 550 ° C. is 5 Continuous annealing is performed for at least 2 seconds, followed by cold rolling. [Selection figure] None

Description

  The present invention relates to a method for producing a steel plate suitable for use in a can lid of an easy open can. In particular, it is related with the manufacturing method of the steel plate for easy open can lids which is excellent in cut shape.

  A so-called easy-open can lid that can open a can and take out food and beverages inside the can body by using a cut called a score in the can lid beforehand, without using a special tool such as a can opener. (Easy Open End, EOE) is used in various beverage cans and food cans including beer cans and carbonated beverage juice cans. The types of such can lids include a “pull-off” type in which a tab that acts as a “lever” or “grip” is cut and separated when the lid is opened, and a state where the tab is attached to the can even after the lid is opened. It is roughly divided into “steion type”. In addition, when divided by the size of the lid, there are a partial easy open end where the opening is partially made with respect to the can diameter and a full easy open end where the entire lid is opened. is there.

  Aluminum alloys are often used for easy open can lids. However, since the aluminum alloy is soft, a material thicker than the steel plate is required in order to give strength against dropping impact and internal pressure rise. However, since aluminum alloys are more expensive than steel plates at the same thickness, the use of aluminum alloys increases costs. Therefore, an easy open can lid using an inexpensive steel plate is desired.

  On the other hand, when a steel plate is used for the easy open can lid, in recent years, from the viewpoint of consumer safety, there is a strict requirement for the shape of the cut opening of the easy open can lid. The open end of the easy-open can lid using steel plates has a sharp pointed shape, and there is a risk that it will be cut if a consumer touches the cut end. The final breaking position (tear-off portion) of the lid is a position that requires special attention because burrs are likely to occur on the outer surface side (consumer side) rather than the contents side.

  As described above, a steel plate that is excellent in cut shape while ensuring the strength of the can lid even when it is thinned is a performance that is recently required for an easy open can lid.

  In order to obtain a steel plate used for an easy open can lid, the following techniques have been proposed.

  In Patent Document 1, mass% as a steel component, C: 0.02% to 0.06%, Si: 0.03% or less, Mn: 0.05% to 0.5%, P: 0.02 %: S: 0.02% or less, Al: 0.02% to 0.10%, N: 0.008% to 0.015%, the balance being in the steel plate made of Fe and inevitable impurities The amount of solute N (Ntotal-NasAlN) is 0.006% or more, the total elongation value in the rolling direction after aging treatment is 10% or more, the total elongation value in the sheet width direction after aging treatment is 5% or more, and A DR steel sheet for EOE, which has an average rankford value after aging treatment of 1.0 or less, has been proposed.

  Patent Document 2 is characterized by containing C: 0.02 wt% or less, B: 0.010 to 0.020 wt%, Al: 0.010 wt% or less, and O: 0.010 to 0.030 wt%. A steel plate for easy open can lids has been proposed.

  In patent document 3, in the open end manufacturing method of an easy open can, the material of the easy open can is C: 0.1 wt% or less, Si: 0.30 wt% or less, Mn: 1.00 wt% or less, Al : 0.005 to 0.20 wt% and N: 0.020 wt% or less, with the balance being composed of Fe and unavoidable impurities, the surface being either a single layer of a metal plating layer or an organic resin coating layer Alternatively, when forming a score at the open end using a cold-rolled steel sheet having a surface treatment layer composed of a plurality of layers or a composite layer of both, first, the pre-shearing amount is 10 A pre-shearing process of ˜50% is performed, and then the reverse shearing process is performed in the opposite direction to the shear breaking by the pre-shearing process and the return shearing process. An open-end manufacturing method with excellent lid opening and opening safety, and excellent rust resistance of the score processed portion, characterized in that the portion is applied under a condition that the portion is 30 to 90% of the plate thickness. .

Japanese Patent No. 5044770 Japanese Patent No. 3740779 Japanese Patent No. 3845994

  With the technology described in Patent Document 1, a DR steel plate with excellent rivet workability can be manufactured, but the cut end of the easy open can lid made with this steel plate has a sharp pointed shape, which is a consumer safety There is a problem.

  With the technique described in Patent Document 2, an easy open can lid having excellent can openability and rivet workability can be manufactured. As in Patent Document 1, the cut end of an easy open can lid made of this steel plate is It has a sharp and pointed shape and has a problem in consumer safety.

  In the technique described in Patent Document 3, the opening of the easy open can lid is smooth. However, in the conventional easy open can lid production facility, there are a press machine and a mold that can perform pre-shear processing and reverse shear processing. However, there is a problem that the cost becomes high in order to newly install a press machine and a die that enable these.

  This invention is made in view of the said subject, Comprising: It aims at providing the manufacturing method of the steel plate for easy open can lids which was excellent in the cut shape, ensuring the intensity | strength of a lid even if it thinned. .

  The inventors of the present invention have made extensive studies to solve the above problems. As a result, it succeeded in manufacturing the steel plate for easy open can lids which was excellent in cut shape by prescribing the amount of Sn thickness center and optimizing the manufacturing conditions. The gist of the present invention is as follows.

  In mass%, C: 0.010% or more, Si: 0.2% or less, Mn: 0.10% or more and 0.60% or less, P: 0.003% or more and 0.150% or less, S: 0.0. 020% or less, Al: 0.01% or more and 0.06% or less, N: 0.02% or less, and Sn content in the central portion of the plate thickness is 0.001% or more and 0.100% or less The remainder is annealed at an annealing temperature of 650 ° C. or higher with respect to a cold-rolled steel sheet having a component composition composed of Fe and inevitable impurities, and then the residence time in the temperature range of 400 ° C. to 550 ° C. is set to 5 seconds or more. A method for producing a steel plate for an easy-open can lid, characterized by performing continuous annealing and then cold rolling.

ADVANTAGE OF THE INVENTION According to this invention, the steel plate for easy open can lids which was excellent in cut shape, ensuring the intensity | strength of a lid | cover, even if it thinned is obtained. By using the steel plate for the easy open can lid of the present invention for the easy open can lid, it is possible to have strength against dropping impact and internal pressure rise without any problem in consumer safety.
Moreover, it is not necessary to perform pre-shear processing and back-shear processing for smoothing the cut surface, it is not necessary to newly install a press die, and the cost is not increased.

FIG. 1 is a diagram illustrating a schematic diagram of a cross-sectional shape of a tear-off portion.

  The steel plate for easy open can lids according to the present invention is, in mass%, C: 0.010% or more, Si: 0.2% or less, Mn: 0.10% or more, 0.60% or less, P: 0.003. %: 0.150% or less, S: 0.020% or less, Al: 0.01% or more and 0.06% or less, N: 0.02% or less, and the Sn content in the center of the plate thickness is 0.001% or more and 0.100% or less, and the balance is 400 ° C. or more and 550 ° C. or less after annealing at an annealing temperature of 650 ° C. or more with respect to a cold-rolled steel sheet having a composition composed of Fe and inevitable impurities. It is manufactured by performing continuous annealing with a residence time in the temperature range of 5 seconds or more, and then cold rolling (secondary cold rolling).

  In the present invention, the steel sheet for the easy open can lid is a cold-rolled steel sheet, a cold-rolled steel sheet with various platings, and a cold-rolled steel sheet with a surface coating such as an organic resin coating or an organic resin film. Including things.

  Hereinafter, each component composition will be described. “%” Representing the content in the description of the component composition means “% by mass”.

C: 0.010% or more If the C content is less than 0.010%, the tensile strength of 400 MPa necessary for an easy open can lid cannot be obtained, and the strength of the can lid decreases. From the above, the C content is 0.010% or more. Preferably it is 0.020% or more. The upper limit of the C content is not particularly limited, but if it exceeds 0.100%, the steel sheet becomes excessively hard, and lid-making workability such as rivet processing deteriorates, so 0.100% or less is preferable.

Si: 0.2% or less When the Si content exceeds 0.2%, the surface treatment property of the steel sheet deteriorates and the corrosion resistance decreases. From the above, the Si content is 0.2% or less. Although the minimum of Si content is not specifically limited, Since reducing Si excessively will cause the steelmaking cost to increase, it is preferable to make Si content 0.004% or more.

Mn: 0.10% or more and 0.60% or less If the Mn content is less than 0.10%, it becomes difficult to avoid hot brittleness even when the S content is reduced, and surface cracking during continuous casting, etc. Problem arises. On the other hand, when the Mn content exceeds 0.60%, the corrosion resistance decreases. From the above, the Mn content is set to 0.10% to 0.60%. Preferably, the Mn content is 0.15% or more and 0.50% or less.

P: 0.003% or more and 0.150% or less When the P content is less than 0.003%, the cost due to de-P is excessive. On the other hand, if the P content exceeds 0.150%, the steel sheet becomes excessively brittle, and strength against dropping impact and internal pressure rise cannot be obtained. From the above, the P content is set to 0.003% or more and 0.150% or less. Preferably it is 0.004% or more and 0.140% or less.

S: 0.020% or less S is a harmful element that forms inclusions in the steel sheet and causes a decrease in hot ductility and deterioration of corrosion resistance of the steel sheet. Therefore, the S content is 0.020% or less. The lower limit of the S content is not particularly limited, but excessively lowering the S causes an increase in the cost of removing S, so the S content is preferably set to 0.004% or more.

Al: 0.01% or more and 0.06% or less Al is an element necessary as a deoxidizing agent during steelmaking. However, if the Al content is less than 0.01%, deoxidation becomes insufficient and inclusions increase, resulting in inclusions. Since stress concentrates on the object and becomes the starting point of the void, it is not possible to obtain the strength against a drop impact or an increase in internal pressure. On the other hand, if Al exceeds 0.06%, the frequency of occurrence of surface defects due to alumina clusters and the like increases. From the above, the Al content is set to 0.01% or more and 0.06% or less. Preferably they are 0.015% or more and 0.055% or less.

N: 0.02% or less When the N content exceeds 0.02%, the steel sheet becomes excessively hard and lid-making workability such as riveting is reduced. From the above, the N content is set to 0.02% or less. The lower limit of the N content is not particularly limited, but excessively reducing N causes an increase in manufacturing cost, so 0.0010% or more is preferable.

  Next, the content of Sn, which is an important requirement of the present invention, will be described.

  Sn is an element that segregates at the grain boundaries and embrittles the steel sheet. If the content is appropriate, Sn has an effect of smoothing the shape of the cut when the easy open can lid is opened. The details are unknown, but when the score of the easy open can lid using normal steel plate breaks, the score part is constricted by ductile fracture and the cut shape becomes sharp and burrs are generated. When Sn segregates at the grain boundary, the grain boundary becomes slightly brittle, so when the score of the easy open can lid breaks, the grain boundary fracture is promoted. Is thought to be smooth. When Sn is concentrated near the surface, a sufficient effect cannot be obtained. Sn is segregated at the center of the plate thickness, and the Sn content in the center of the plate thickness is 0.001% or more and 0.100% or less, thereby providing an easy open can lid steel plate having an excellent cut shape. it can.

The Sn content in the center portion of the plate thickness is 0.001% or more and 0.100% or less. If the Sn content in the center portion of the plate thickness is less than 0.001%, the effect on the cut shape cannot be obtained. The shape becomes sharp. If the Sn content in the central portion of the plate thickness exceeds 0.100%, the steel plate becomes excessively brittle and strength against dropping impact and internal pressure rise cannot be obtained. From the above, the Sn content in the center portion of the plate thickness is set to 0.001% or more and 0.100% or less. Preferably it is 0.003% or more and 0.080% or less.

  In the present invention, the plate thickness center portion is a plate thickness center portion 1/2 t ± 25% (t: plate thickness). That is, it is a region obtained by combining a region of 25% of the plate thickness from the plate thickness central portion 1 / 2t to the steel plate surface and a region from the plate thickness central portion 1 / 2t to the steel plate back surface of 25% of the plate thickness.

  Further, the Sn content in the central portion of the plate thickness is obtained by exposing the central portion of the steel plate thickness by a method such as mechanical grinding or chemical polishing, and the iron and steel-tin determination method (JIS G1226) or iron and steel- It can be measured by a method such as a spark discharge emission spectroscopic analysis method (JIS G1253) or an iron and steel-fluorescent X-ray analysis method (JIS G1256).

  In addition, about Sn content of the whole steel plate, since it does not affect the effect of this invention, it does not specifically limit.

  The balance is Fe and inevitable impurities.

  In addition, Cu, Ni, Cr, Mo and other elements can be contained for the purpose of securing tensile strength within a range not impairing the effects of the present invention. However, when it contains excessively, corrosion resistance will fall. Therefore, when contained, Cu is 0.2% or less, Ni is 0.15% or less, Cr is 0.10% or less, Mo is 0.05% or less, and other elements (for example, Ti, Nb, B). ) Is 0.02% or less.

  For the cold-rolled steel sheet having the above component composition, after annealing at an annealing temperature of 650 ° C. or higher, continuous annealing is performed with a residence time in the temperature range of 400 ° C. or higher and 550 ° C. or lower being 5 seconds or longer, then cold Roll (secondary cold rolling).

Continuous annealing process After annealing the cold-rolled steel sheet having the above component composition at an annealing temperature of 650 ° C or higher, heat treatment is performed so that the residence time in the temperature range of 400 ° C to 550 ° C is 5 seconds or longer. When the area ratio of the non-recrystallized structure exceeds 5%, the material in the steel plate becomes non-uniform and the formability deteriorates, the shape deteriorates even if it is processed into a can lid, and there is a gap in the winding part of the can body The annealing temperature is set to 650 ° C. or higher because the pressure strength is inferior. The upper limit of the annealing temperature is not particularly limited, but it is preferably annealed at 750 ° C. or lower in order to increase the manufacturing cost. The residence time of 650 ° C. or higher is not particularly limited, but if it is less than 5 seconds, the non-recrystallized structure may exceed 5%, and if it exceeds 100 seconds, recrystallization becomes saturated and the cost increases. The time is preferably from 100 seconds to 100 seconds. After annealing at 650 ° C. or higher, heat treatment is performed for a residence time in the temperature range of 400 ° C. or higher and 550 ° C. or lower for 5 seconds or longer. In order to obtain an excellent cut shape, it is necessary to promote grain boundary segregation of Sn, but when the residence time in the temperature range of 400 ° C. or more and 550 ° C. or less is less than 5 seconds, the grain boundary segregation is not sufficient, An excellent cut shape cannot be obtained. The upper limit of the residence time is not particularly limited, but if it exceeds 100 seconds, the grain boundary segregation is saturated and the cost is increased.

Cold rolling process (secondary) cold rolling is performed on the annealed steel sheet obtained in the continuous annealing process. The upper limit of the cold rolling reduction is not particularly limited, but if it exceeds 40%, the steel sheet becomes excessively hard and it becomes difficult to process the can lid, so the rolling reduction of the secondary cold rolling is 40% or less. preferable. The lower limit of the rolling reduction is not particularly limited, but 5% or more is preferable in order to stably obtain a tensile strength of 400 MPa or more. The sheet thickness of the steel sheet after cold rolling is not particularly limited, but the sheet thickness of the steel sheet after cold rolling is preferably 0.20 mm or less in order to obtain an economic effect by thinning.

  The steel plate for easy open can lids obtained as described above can be subjected to surface treatment such as various plating treatments, organic resin coating, organic resin coating, and the like as necessary. A surface-treated steel sheet can be obtained by forming a plating layer on the surface of the steel sheet by, for example, electroplating, such as tin plating, chromium plating, or nickel plating. Although it does not specifically limit as a surface treatment process, It is preferable to set it as either a well-known nickel plating process, a tin plating process, or a chromium plating process, and any of a nickel plating layer, a tin plating layer, and a chromium plating layer is preferable as a surface treatment layer. It can be set as the surface treatment steel plate which has these. Moreover, you may perform the surface treatment process which carries out the tin plating of ultra-thin weight after the special base treatment, or the surface treatment process which sticks a polymer organic film. In addition, since the film thickness of surface treatments, such as plating, is sufficiently small with respect to plate | board thickness, the influence on the mechanical characteristics of the steel plate for easy open can lid | covers is a level which can be disregarded.

  In addition, in order to obtain the cold-rolled steel plate used for a continuous annealing process, you may provide a hot rolling process, a pickling process, and a primary cold rolling process prior to a continuous annealing process.

  In the hot rolling process, steel adjusted to the above component composition is melted in a converter or the like, and is made into a slab by a continuous casting method or the like. The slab to be used is preferably produced by a continuous casting method in order to prevent macro segregation of components, but may be produced by an ingot-making method or a thin slab casting method. Also, after manufacturing the slab, after cooling to room temperature and then heating again, do not cool to room temperature, and then insert it into a heating furnace as it is, or carry out slight heat retention Energy saving processes such as direct feed rolling and direct rolling, which are rolled immediately, can be applied without any problem.

  The slab used in the hot rolling process may be heated. In the case of heating, the slab heating temperature is preferably low temperature heating in terms of energy. However, if the heating temperature is less than 1100 ° C., the rolling load is not stable, and the productivity is deteriorated. On the other hand, the slab heating temperature is preferably set to 1300 ° C. or lower because of an increase in scale loss accompanying an increase in oxidized weight. Even when the slab heating temperature is lowered, a so-called sheet bar heater that heats the sheet bar may be used from the viewpoint of preventing troubles during hot rolling.

  The finish rolling temperature in the hot rolling step is preferably 850 ° C. or higher from the viewpoint of rolling load stability. On the other hand, raising the finish rolling temperature more than necessary may make it difficult to produce a thin steel sheet. Specifically, the finish rolling temperature is preferably in the temperature range of 850 to 960 ° C. The upper limit of the coiling temperature is not particularly limited. However, if the coiling temperature is excessively high, the scale thickness on the surface of the steel sheet becomes thick, and the descalability in pickling in the pickling process is deteriorated. On the other hand, the lower limit of the coiling temperature is not particularly limited, but if the coiling temperature is excessively decreased, the strength of the hot-rolled steel sheet obtained in the hot rolling process is increased, and the rolling load in the primary cold rolling process is increased. Since the control becomes difficult, the winding temperature is preferably 500 ° C. or higher.

  In the hot rolling in the present invention, part or all of the finish rolling may be lubricated rolling in order to reduce the rolling load during hot rolling. Performing lubrication rolling is also effective from the viewpoint of uniform steel plate shape and uniform material. The coefficient of friction during lubrication rolling is preferably in the range of 0.25 to 0.10. Moreover, it is preferable to set it as the continuous rolling process which joins the sheet | seat bars which precede and follow and finish-rolls continuously. The application of the continuous rolling process is also desirable from the viewpoint of the operational stability of hot rolling.

  The pickling step is a step of removing the oxidized scale on the surface of the hot-rolled steel sheet obtained in the hot rolling step by pickling. Pickling conditions are not particularly limited, and may be set as appropriate. Further, instead of pickling, a method such as mechanical removal may be used.

  The primary cold rolling step is a step of cold rolling the pickled plate after the pickling step. The cold rolling conditions are not particularly limited. For example, the conditions such as the rolling reduction may be determined from the viewpoint of the desired sheet thickness. In order to finish the sheet thickness of the steel sheet after secondary cold rolling thin, 85 to 94% is preferable.

  The steel plate for easy open can lids of this invention is obtained by the above. From the standpoint of further obtaining the effects of the present invention, the thickness of the present invention is preferably 0.20 mm or less.

  The structure of the steel sheet for easy open can lids of the present invention produced as described above is preferably a recrystallized structure. This is because if there is an unrecrystallized structure after continuous annealing, the material becomes non-uniform and it becomes difficult to process the can lid. If the area ratio of the unrecrystallized structure is 5% or less, it is acceptable because it hardly affects the processing of the can lid. The recrystallized structure is preferably a ferrite phase, and the phase other than the ferrite phase is preferably less than 1.0%.

  Moreover, the steel plate for easy open can lids of this invention manufactured by the above is 400 MPa or more in tensile strength. When the tensile strength is less than 400 MPa, the steel sheet cannot be made thin enough to obtain a remarkable economic effect while securing the strength as a can lid. Therefore, the tensile strength is 400 MPa or more.

  An easy open can lid can be produced by a known method using the above-described steel plate for easy open can lid. The easy open can lid thus obtained has the necessary strength as an easy open can lid, has an excellent cut shape, and can be reduced in thickness, thereby reducing the amount of waste generated during use. It also has an effect.

  It contains the component composition shown in Table 1, and the balance is continuously annealed under the annealing conditions shown in Table 2 with respect to the cold rolled steel sheet made of Fe and inevitable impurities, and subsequently at the rolling reduction shown in Table 2 (secondary) Cold rolling was performed to make the plate thickness 0.18 mm. The obtained steel sheet was subjected to electrolytic chromic acid treatment to obtain tin-free steel. In addition, the content of Sn in Table 1 is a value obtained by analyzing the central portion of the plate thickness after the electrolytic chromic acid treatment. The cold-rolled steel sheet is obtained by melting steel in a converter and continuously casting it to obtain a steel slab. The resulting steel slab is reheated to 1220 ° C. and then finish-rolled at 890 ° C. After application, the film was wound at 650 ° C., then pickled, and subjected to primary cold rolling at a rolling reduction of 90%.

  The steel plate obtained as described above was subjected to a heat treatment equivalent to coating baking at 210 ° C. for 15 minutes, and then a tensile test was performed. The tensile test was performed according to “JIS Z 2241” using a JIS No. 5 size tensile test piece, and the tensile strength in the rolling direction was measured.

  Further, the obtained steel sheet was subjected to a heat treatment equivalent to coating baking at 210 ° C. for 15 minutes, then formed into a 63 mmΦ can lid, and wound and attached to a 63 mmΦ weld can body. The compressive strength was evaluated by the pressure when the compressed air was introduced into the can and the can lid was deformed. The case where the can lid was not deformed even when the internal pressure was 0.2 MPa or more was marked with ◯, and the case where the can lid was deformed below 0.2 MPa was marked with x. Alternatively, even when air leaks from the tightening portion and the pressure cannot be increased to 0.2 MPa, the pressure resistance strength as a can lid is inferior, and x is given.

  Further, the obtained steel sheet was subjected to a heat treatment equivalent to coating baking at 210 ° C. for 15 minutes, and then formed into a 63 mmφ full-easy open can lid. The remaining amount of the plate thickness after score processing (score remaining thickness) was 50 μm. The full easy open can lid was opened manually. The cut shape was evaluated by the presence / absence of burrs on the outer surface side of the tear-off portion, and x was given when burrs were present, and ◯ was given when there were no burrs. FIG. 1 shows a schematic diagram of a cross-sectional shape of the tear-off portion.

  From Table 3, the steel plate for easy open can lids which is excellent in a cut shape is obtained in the example of the present invention.

  On the other hand, in the comparative example, either the pressure strength or the cut shape is inferior.

  No. No. 4 has a P content exceeding 0.150% outside the range of the present invention, and the pressure strength is inferior.

  No. In No. 5, the Sn content in the central portion of the plate thickness exceeds the range of the present invention and exceeds 0.100%, and the pressure resistance is inferior.

  No. In No. 6, the Sn content in the thickness center portion is less than 0.001% outside the range of the present invention, and the cut shape is inferior.

  No. No. 7 has a C content of less than 0.010% outside the range of the present invention, and the pressure strength is inferior.

  No. No. 8 has a residence time in the temperature range of 400 to 550 ° C. is less than 5 seconds outside the scope of the present invention, and the cut shape is inferior.

  No. No. 9 has an annealing temperature outside the range of the present invention, which is less than 650 seconds, and the shape is poor even when processed into a can lid. The air leaks out and the pressure cannot be increased to 0.2 MPa, and the pressure strength is inferior.

Claims (1)

In mass%, C: 0.010% or more, Si: 0.2% or less, Mn: 0.10% or more and 0.60% or less, P: 0.003% or more and 0.150% or less, S: 0.0. 020% or less, Al: 0.01% or more and 0.06% or less, N: 0.02% or less, and Sn content in the central portion of the plate thickness is 0.001% or more and 0.100% or less The remainder is a cold-rolled steel sheet having a component composition consisting of Fe and inevitable impurities.
After annealing at an annealing temperature of 650 ° C. or higher, continuous annealing is performed in which the residence time in the temperature range of 400 ° C. or higher and 550 ° C. or lower is 5 seconds or longer,
Next, a method for producing a steel plate for an easy open can lid, which is cold-rolled.