JPH10317180A - Production of cold rolled and plated steel sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a cold rolled and plated steel sheet by which harmful reactants produced in the process of annealing for a steel sheet is suppressed and a cold rolled and plated steel sheet having uniform surface properties can easily and efficiently be produced. SOLUTION: In the method for producing a cold rolled and plated steel sheet 23 in which a thin steel sheet 11 obtd. by executing cold rolling is immersed in a treating soln. 12 to remove depositions on the surface, which is immersed in a washing soln. 15 and is formed into a washed steel sheet 18, and next, this washed steel sheet 18 is subjected to annealing treatment and is applied with plating treatment of tin, chromium or the like, the coating weight of sulfuric acid components and/or chlorine components is regulated to suppress the reaction of the sulfuric acid components and chlorine components with the washed steel sheet 18 in the annealing stage and to prevent surface defects generated after the plating treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a beautiful cold-rolled steel sheet having no surface defects.

[0002]

2. Description of the Related Art Cold rolled plated steel sheets used for beverage cans and the like are required to have a clean and beautiful impression with a uniform surface property, particularly in view of hygiene and aesthetic requirements. Materials such as tin cans made of tin-plated steel and tin-free-steel (TFS: Tin-Free-Steel) plated with chrome are used by users such as can manufacturers. As the quality requirement level of the GaN increases, the improvement of the surface appearance is required at a higher level. Tinplate and TFS materials for beverage cans and the like have a very thin plating film, so not only to improve the plating method, but also to increase the cleanliness of the cold-rolled steel sheet as the original plate for forming beautiful plating appearance. Need to be kept. A typical example of a method for reducing the cleanliness of a cold-rolled steel sheet is formation of an oxide film as disclosed in Japanese Patent Application Laid-Open No. 7-70799. After that, it is pressed with a rubber ringer roll, drains the liquid, and further measures the amount of water adhering to the steel plate with a moisture measuring device in the upper stage,
If the amount exceeds the predetermined amount, adjust the pressing device of the rubber ringer roll to adjust the amount of water to be equal to or less than the predetermined amount of water.
A cold-rolled steel sheet to be annealed by adjusting the residual moisture content to not more than g / m ² has been proposed, and a cold-rolled steel sheet having an oxide film formed on the original sheet having a thickness of 30 Å or less has been proposed. I have. Japanese Patent Application Laid-Open No. Hei 6-262241 discloses that any one of three types of unsteady states, that is, when the liquid-absorbing ringer roll is closed, when the metal strip passes through a different-width joining portion, or when the metal strip is accelerated, is set to be in an unsteady state. It senses in advance when it will be
A method has been proposed in which, when the state changes to the unsteady state, the suction vacuum pressure of the liquid-absorbing ringer roll is temporarily increased to increase the suction flow rate, thereby shortening the response delay time of the liquid drainage capability.

[0003]

However, in the case of a method in which a cold-rolled steel sheet described in Japanese Patent Application Laid-Open No. 7-70799 is plated and used as a beverage can or the like, the following is shown. There was such a problem. The washing water used in washing with water or the washing solution used in alkaline electrolytic washing contains residue components that are concentrated on the original plate and adhered as solids in the washing process and high-temperature drying process,
When the steel sheet to which the residue component adheres is annealed at a high temperature, the residue component reacts with the surface of the steel sheet to generate a unique reactant. Such a reactant cannot be easily removed by a subsequent pickling treatment or the like. When a steel sheet on which the reactant is formed is subjected to plating treatment, a streak pattern is formed on the plated surface, and the The appearance as a can is significantly impaired. When the ringer roll is pressed against the steel plate surface and comes into contact with the ringer roll, water droplets tend to remain in a streak shape along the rotation direction of the ringer roll, and are hung on the pressing device of the ringer roll. By adjusting the pressing pressure,
It is difficult to completely remove this. Since the oxide film formed on the steel plate can be easily removed by the subsequent pickling treatment, the load on production is small, but on the other hand, there is a problem that only the cost required for adjusting the amount of adhering water increases. Further, Japanese Patent Application Laid-Open No.
In the method using the absorbent ringer roll described in
A control mechanism for adjusting the suction vacuum pressure applied to the liquid-absorbing ringer roll is required, and this management is complicated. The present invention has been made in view of such circumstances, and suppresses generation of harmful reactants generated during annealing of a steel sheet to easily and efficiently produce a cold-rolled plated steel sheet having a uniform surface texture. It is an object of the present invention to provide a method for producing a cold-rolled plated steel sheet that can be performed.

[0004]

According to the present invention, there is provided a semiconductor device comprising:
The method for producing a cold-rolled plated steel sheet according to the method described above is to immerse a thin steel sheet obtained by cold rolling in a treatment liquid to remove surface deposits, and then immerse the cleaning liquid in a cleaning liquid, and then use this as a cleaning steel sheet. In the method for producing a cold-rolled steel sheet in which a washed steel sheet is annealed and plated with tin, chromium, or the like, the amount of sulfuric acid and / or the amount of chlorine adhering to the washed steel sheet is adjusted, and the annealing treatment is performed. And the reaction between the sulfuric acid component and chlorine component and the cleaning steel sheet in the above is suppressed, and surface defects generated after the plating treatment are prevented. The method for producing a cold-rolled plated steel sheet according to claim 2 is the method for producing a cold-rolled plated steel sheet according to claim 1, wherein the sulfuric acid content and / or the chlorine content are attached to the thin steel plate. A first draining device for draining a cleaning liquid, a steam cleaning device for spraying steam to the thin steel plate after draining, and a second draining device for draining the thin steel plate taken out from the steam cleaning device Adjust using. The method for producing a cold-rolled steel sheet according to claim 3 is the method for producing a cold-rolled steel sheet according to claim 1 or 2, wherein the sulfuric acid content of the washed steel sheet is 0.7 mg.
/ M ² or less. The method for producing a cold-rolled plated steel sheet according to claim 4 is the method for producing a cold-rolled plated steel sheet according to any one of claims 1 to 3, wherein a chlorine content of the washed steel sheet is 1.4 mg / m. Control to ² or less. Claim 5
In the method for producing a cold-rolled steel sheet according to any one of claims 1 to 4, the cold-rolled steel sheet is a plated steel sheet for a beverage can.

[0005] The sulfuric acid content is a value obtained by converting the weight of the sulfate group (SO ₄ ) in the sulfate compound in the deposit on the thin steel plate into a unit area of the thin steel plate. The chlorine content refers to a value obtained by converting the weight of chlorine (Cl) in the chlorine compound in the deposits remaining on the thin steel sheet into a unit area of the thin steel sheet. The cold-rolled steel sheet is a common tin material obtained by tinning the steel sheet, and a tin-free chrome-plated steel sheet TFS (tin-free steel material)
Etc. are included. 0.7mg /
In the case of exceeding m ² , the sulfuric acid component reacts with the components of the steel sheet when annealing the washed steel sheet, and after plating this, increases the incidence of surface defects such as streak-like residual liquid patterns. It is not preferable because it becomes a factor. Regarding the chlorine content of the cleaned steel sheet, if the chlorine content exceeds 1.4 mg / m ² , a reaction between the chlorine content and the steel sheet component occurs similarly during the annealing of the washed steel sheet, and this is subjected to a plating treatment. The occurrence of surface defects becomes more remarkable.

According to the present invention, it is possible to suppress the production of Fe-S based composite oxides and chlorine-induced iron compounds which are difficult to remove in an electrolytic pickling or immersion pickling facility installed upstream of an electroplating line. As a result, abnormal growth of iron oxide and the like can be prevented, and a cold-rolled plated steel sheet having a beautiful plated appearance can be manufactured. In addition, by spraying water vapor on the thin steel plate after draining once, the harmful compound can be more efficiently removed, so that use of expensive washing water such as pure water or a liquid absorbing ringer roll or the like which is difficult to manage is used. Use can be avoided, and increase in production cost and line stoppage for ringer roll replacement can be minimized.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention. Here, FIG. 1 is an explanatory view of a cold-rolled plated steel sheet production equipment to which the method for producing a cold-rolled plated steel sheet according to the first embodiment of the present invention is applied, and FIG. FIG. 3 is a diagram showing the relationship between the evaluation of remaining liquid pattern generation and the amount of attached chlorine, FIG. 4 is a diagram showing the relationship between the evaluation of occurrence of remaining liquid pattern and the amount of attached sodium,
FIG. 5 is a diagram showing the relationship between the evaluation of the appearance of the remaining liquid pattern and the amount of attached calcium, FIG. 6 is a diagram showing the relationship between the evaluation of the appearance of the remaining liquid pattern and the amount of attached hydroxyl, and FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing of the cold rolling plated steel plate manufacturing equipment which applied the manufacturing method of the cold rolled plated steel plate which concerns on embodiment.

[0008] Cold rolled steel sheet manufacturing equipment 1 to which the method for manufacturing a cold rolled steel sheet according to the first embodiment of the present invention is applied.
0 is a degreasing treatment tank 14 for immersing the thin steel plate 11 in a degreasing liquid 12 which is an example of a treatment liquid to remove surface deposits such as grease, as shown in FIG. The thin steel plate 11 thus obtained is immersed in the cleaning liquid 15 to remove the degreasing liquid 12.
Cleaning tank 16 (also called a rinsing tank)
A ringer roll 17 which is an example of a drainer for draining the thin steel plate 11 pulled up from the cleaning tank 16, and a washed steel plate 18 treated by the ringer roll 17
A component analyzer 19 for measuring the amount of residual components adhering to the steel sheet, an annealing furnace 20 for annealing the cleaning steel sheet 18 to adjust it to a predetermined softness, and pressure-controlling the annealed annealing steel sheet 21. And a plating apparatus 22 for obtaining a cold-rolled plated steel sheet 23 plated with tin or chromium after removing an oxide film formed in the annealing furnace 20 by pickling.

The degreasing tank 14 contains sodium hydroxide (N
aOH) a solution tank for holding a degreasing solution 12 such as an aqueous solution, which continuously processes a thin steel sheet 11 supplied through a dipping roll 13 disposed in the tank, and performs a thin-rolled steel sheet 11 in a cold rolling process or the like. Can be removed by eluting fats and the like adhering to the surface. Note that, instead of the degreasing tank 14, an electrolytic bath for performing alkaline electrolytic cleaning can also be used.
May be continuously subjected to a surface treatment with an electrolytic bath and a degreasing solution 12. The cleaning tank 16 is an apparatus for immersing the thin steel plate 11 in a cleaning liquid 15 such as industrial water or the like to continuously clean the processing liquid 12 or the like adhering to the surface thereof. Ringer roll 1
7, a thin steel plate 11 is fed between a pair of rolls made of urethane rubber or the like, the front and back of the thin steel plate 11 are sandwiched between rolls and pressed, and drainage of water or the like adhering to the surface is performed for cleaning. This is a device for forming a steel plate 18. FIG. 1 shows a case where a pair of ringer rolls 17 are arranged, but two or more ringer rolls can be arranged between the cleaning tank 16 and the annealing furnace 20 as necessary.

The component analyzer 19 is a device for measuring sulfuric acid, chlorine, calcium, sodium, hydroxyl group and the like adhering to the cleaning steel plate 18. For example, a part of the cleaning steel plate 18 is cut and tested. After preparing a piece, a test piece having a predetermined area is immersed in the extract, and the amount of each ion contained in the extract is measured, thereby converting each component per unit area of the washed steel sheet 18. A chemical analyzer that calculates the attached amount, an analyzer that applies the principle of X-ray spectroscopy, or the like can be applied. In addition, the component analyzer 1
As a means for measuring the amount of adhesion in place of 9, the degreasing tank 1
4. For each treatment condition in the cleaning tank 16 and the ringer roll 17, a data table is prepared by previously measuring the amount of the specific component adhering to the cleaning steel plate 18 by chemical analysis or the like,
It is also possible to determine the amount of adhesion corresponding to the actual processing condition based on this data table. Further, the chlorine ion concentration C _c in the cleaning liquid 15 (mg / l), coating weight W _a of the cleaning liquid 15 adhering component concentrations such as sulfuric acid ion concentration C _s (mg / liter), and washed steel plate 18 per unit area (Mg / m ² ), and the chlorine content W remaining as a solid content when the volatile components of the cleaning liquid 15 are removed.
_{c (= K c × C c} × W a), sulfuric acid content coating weight W _s (= K _s
× C _s × W _a ) may be calculated. The unit of each adhesion amount is mg / m ² , and K _c and K _s are conversion coefficients set for each component. The annealing furnace 20 continuously feeds the washed steel sheet 18 to, for example, 600 to 780 ° C., preferably 650 to 7000C.
This is a device that heats to a temperature of 00 ° C. and adjusts the hardness of the steel sheet work-hardened by cold rolling or the like to a predetermined range. When the washed steel sheet 18 to which sulfuric acid and chlorine are adhered is subjected to heat treatment in the annealing furnace 20, the sulfuric acid and chlorine react with the steel sheet, and tend to cause surface defects such as flow patterns after the subsequent plating.

Subsequently, the cold-rolled steel sheet manufacturing equipment 10
A method for manufacturing a cold-rolled plated steel sheet according to the first embodiment of the present invention applied to the present invention will be described. First, a cold-rolled thin steel plate 11 taken out from a coil dispenser (not shown) is immersed in a treatment liquid 12 in a degreasing tank 14 to perform a degreasing treatment. Next, the treated thin steel plate 11 is removed from the cleaning tank 16.
After being treated under a predetermined transport speed, a cleaning liquid temperature, and cleaning conditions to be a cleaning liquid component, pulled up from the cleaning liquid 15, and passed through a ringer roll 17 set at a predetermined pressure and a predetermined number of rotations, the cleaning steel plate is washed. It is assumed to be 18. After measuring the amounts of sulfuric acid and chlorine adhering to the cleaning steel sheet 18, the cleaning steel sheet 18 is sent to an annealing furnace 20, where the cleaning steel sheet 18 is annealed. Then, the annealed annealed steel sheet 21 is fed into the plating apparatus 22 to finally obtain a cold-rolled plated steel sheet 23 plated with chromium or tin. Note that the annealed steel sheet 21 may be once wound and held by a winder (not shown) without being directly sent from the annealing furnace 20 to the plating apparatus 22. In such a cold-rolled steel sheet 23, during the annealing process of the cleaning steel sheet 18, the harmful component adhering to the cleaning steel sheet 18 reacts with the component of the steel sheet, and this portion becomes a surface defect called a liquid residue pattern by the plating process. The expression was revealed by the experiments shown below by the present inventors. In the present embodiment, by controlling the sulfuric acid content and the chlorine content in the cleaning steel sheet 18 to be equal to or less than the limit value of the occurrence of surface defects set based on the experimental results, The purpose is to prevent surface defects occurring in the steel plate 23.

FIGS. 2 to 6 show sulfuric acid, chlorine, sodium, calcium,
It shows the result of experimentally determining the relationship between the adhesion amount of hydroxyl and the amount of hydroxyl content and the evaluation of the occurrence of a residual liquid pattern on the cold-rolled plated steel sheet 23. Here, the remaining liquid pattern generation evaluation is such that the remaining liquid pattern does not appear after pickling and plating after removing the oxide film (symbol: ○), and the remaining liquid pattern appears after pickling.
The three-level evaluation of a state that does not appear after plating (symbol: Δ) and a state that a residual liquid pattern appears after plating (symbol: ×) are shown. 2 to 6 indicate the weight W (mg / m ² ) per unit area of the cleaning liquid 15 adhered to the surface of the cleaning steel plate 18 measured on the exit side of the ringer roll 17 and the cleaning liquid 15. An example of a variation range of each adhesion amount in an actual machine, which is set based on a product (= W × C) of each component concentration C (wt%) included therein, is shown.

As apparent from FIGS. 4 to 6, sodium (Na), calcium (Ca), and hydroxyl (O)
Even if the amount of each of H) increases or decreases, no liquid remaining pattern occurs (symbol:）), indicating that there is no influence of the amount of the adhesion. On the other hand, in the case of the sulfuric acid and chlorine adhering amounts shown in FIGS. 2 and 3, it can be seen that the evaluation of the occurrence of the liquid remaining pattern worsens as the adhering amounts of the respective components increase.
Therefore, by adjusting the sulfuric acid content and the chlorine content to a specific range where the residual liquid pattern is less likely to occur, it is possible to prevent the occurrence of surface defects after the plating process. For example, as shown in FIGS. 2 and 3, the sulfuric acid content and the chlorine content were 0.7 mg / m ² and 1.4, respectively.
By controlling the concentration to not more than mg / m ² , it is possible to achieve a state (symbol: Δ, ○) in which no residual liquid pattern occurs after the plating treatment. Such adjustment of the amount of adhesion can be performed, for example, by controlling the sulfate ion concentration and the chloride ion concentration in the cleaning liquid 15, the pressure of the ringer roll, the supply speed of the thin steel plate 11 to the ringer roll 17, and the like. . This makes it possible to efficiently manufacture the cold-rolled plated steel sheet 23 having a beautiful plated appearance, and to obtain a plated steel sheet suitable for use in beverage cans, in which appearance evaluation is strictly required.

Next, a method of manufacturing a cold-rolled steel sheet according to a second embodiment of the present invention will be described. Note that the cold-rolled steel sheet manufacturing equipment 30 to which this manufacturing method is applied is replaced with the ringer roll 17 in the cold-rolled steel sheet manufacturing equipment 10 of the first embodiment, and is a ringer roll which is an example of a first liquid drainer. 32, a steam cleaning device 31 disposed downstream of the ringer roll 32, and a ringer roll 33, which is an example of a second liquid draining device, disposed downstream of the steam cleaning device 31. Since they are almost the same, they are denoted by the same reference numerals,
Detailed description is omitted. As shown in FIG. 7, the cold-rolled steel sheet manufacturing equipment 30 includes a degreasing treatment tank 14 such as an alkaline electrolytic tank for immersing the thin steel sheet 11 in the treatment liquid 12 to remove surface deposits such as grease, and the like. A cleaning tank 16 for immersing the thin steel sheet 11 processed in the processing tank 14 in the cleaning liquid 15 to remove the processing liquid 12 and the like, and a ringer roll 32 for draining the thin steel sheet 11 pulled up from the cleaning tank 16. And a steam washing device 31 for spraying steam following the ringer roll 32 onto the thin steel plate 11, a ringer roll 33 for draining the thin steel plate 11 taken out from the steam washing device 31, and a treatment with the ringer roll 33. Component analyzer 19 for measuring the amount of the residual component adhering to the cleaned cleaning steel sheet 18, an annealing furnace 20 for annealing the cleaning steel sheet 18, and annealed annealing steel 21 has a plating treatment device 22 for obtaining a cold-rolled steel sheet 23 plated with tin or chromium after removing the oxide film formed in the annealing furnace 20 or the like by pickling. doing.

The steam cleaning device 31 has a temperature of, for example, 15
A cleaning device for spraying steam having a pressure of 0 to 500 ° C. and a pressure of 1 to 15 kg / cm ² onto the surface of the thin steel plate 11 to efficiently remove the cleaning liquid 15 or the surface deposits on the thin steel plate 11. The amount V (kg / m ² ) of steam sprayed per unit area of the thin steel plate 11 can be set, for example, as follows. First, the minimum values V _s and V _c of the steam spray amount V for the sulfuric acid component and the chlorine component are calculated using the following equations (1) and (2). ^{_{V s = W a 2 · C}} s · K / 0.7-W a · (10 -3 g / mg) ··· (1) V c = W a 2 · C c · K / 1.4-W _a · (10 ⁻³ g / mg) (2) where C _s and C _c are the sulfuric acid concentration (mg / l) and the chlorine concentration (mg / l) in the washing solution 15, respectively.
It is. W _a is wringer roll 32 or a water adhesion amount at the delivery side of the wringer roll 33 (mg / m ^2),
K represents a unit conversion coefficient and is a numerical constant of 0.7, 1..
4 is a sulfuric acid content to prevent the formation of a liquid residue pattern,
It is the limit adhesion amount of chlorine (mg / m ² ). And
V _s and V calculated respectively by the equations (1) and (2)
_The higher value of _c is _VL , and the vapor spray amount V is V
_The thin steel plate 11 can be cleaned by setting the range to be _L or more. By this steam spray, the sulfuric acid component and the chlorine component attached to the surface of the thin steel plate 11 are efficiently diluted and removed, and the cleaning efficiency of the thin steel plate 11 can be maintained at a predetermined level.

In the second embodiment, since the ringer roll 33 is provided on the downstream side of the steam cleaning device 31, the adhered water condensed with the steam is removed from the surface of the thin steel plate 11 and the predetermined water is removed. A clean washed steel plate 18 adjusted to a sulfuric acid content and a chlorine content that are equal to or less than the reference value can be obtained. Then, when adjusting the respective adhesion amounts, the sulfate ion concentration, the chloride ion concentration,
In addition to adjusting the pressing pressure of the ringer roll 32, the supply speed of the thin steel plate 11 to the ringer roll 32, etc., the steam spray amount V, steam temperature, steam pressure,
Alternatively, by adjusting the operating conditions of the ringer roll 33, each amount of adhesion can be controlled to an appropriate range. This makes it possible to efficiently and efficiently manufacture a cold-rolled plated steel sheet 23 having a beautiful plated appearance for beverage cans and the like.

The embodiment of the present invention has been described above.
The present invention is not limited to these embodiments, and all changes in conditions without departing from the gist are within the scope of the present invention. For example, in the present embodiment, an example in which a ringer roll is used as a liquid draining device has been described, but a compressed air jetting device that blows high-pressure air onto the surface of a thin steel plate to remove it, or a liquid absorbing type that has a vacuum suction mechanism May be used.

[0018]

In the method for producing a cold-rolled steel sheet according to any one of claims 1 to 5, the sulfuric acid content and / or the chlorine content attached to the washed steel sheet are adjusted so that the sulfuric acid content and the chlorine content in the annealing treatment are adjusted. Since the reaction between the surface and the cleaning steel sheet is suppressed and the surface defects generated after the plating treatment are prevented, the rate of occurrence of surface defects such as a liquid residue pattern can be reduced, and a beautiful cold-rolled steel sheet can be efficiently manufactured. The production yield can be improved. In the method for producing a cold-rolled plated steel sheet according to claim 2, a first draining device for draining a cleaning liquid that adheres to a thin steel plate, the amount of sulfuric acid and / or the amount of chlorine attached, and steam after draining. Steam cleaning equipment that sprays
In addition, since the adjustment is performed using the second liquid removal device that performs liquid removal of the thin steel plate taken out from the steam cleaning device, the incidence of surface defects such as liquid residue patterns can be further effectively reduced. In the method for manufacturing a cold-rolled steel sheet according to claim 3, the sulfuric acid content of the washed steel sheet is controlled to a specific value or less, so that the reaction between the sulfuric acid content and the steel sheet component in the annealing process is further effectively suppressed. Can be. In the method for producing a cold-rolled plated steel sheet according to claim 4, since the amount of chlorine attached to the washed steel sheet is controlled to a specific value or less, generation of harmful reactants due to chlorine and steel sheet components is suppressed, and The incidence of defects can be further reduced. In the method for producing a cold-rolled plated steel sheet according to the fifth aspect, since the cold-rolled plated steel sheet is a plated steel sheet for a beverage can, the production yield of the plated steel sheet for a beverage can with particularly strict quality standards for surface properties is improved. Can be done.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a cold-rolled plated steel sheet manufacturing equipment to which a method for manufacturing a cold-rolled plated steel sheet according to a first embodiment of the present invention is applied.

FIG. 2 is a diagram showing the relationship between the evaluation of occurrence of a liquid residue pattern and the amount of sulfuric acid attached.

FIG. 3 is a diagram showing the relationship between the evaluation of the occurrence of a liquid residue pattern and the amount of adhered chlorine.

FIG. 4 is a diagram showing the relationship between the evaluation of the occurrence of a residual liquid pattern and the amount of sodium content.

FIG. 5 is a diagram showing the relationship between the evaluation of the occurrence of a liquid remaining pattern and the amount of adhered calcium.

FIG. 6 is a diagram showing the relationship between the evaluation of the occurrence of a liquid residue pattern and the amount of attached hydroxyl components.

FIG. 7 is an explanatory view of a cold-rolled plated steel sheet manufacturing equipment to which a method for manufacturing a cold-rolled plated steel sheet according to a second embodiment of the present invention is applied.

[Explanation of symbols]

Reference Signs List 10 Cold rolled plated steel sheet manufacturing equipment 11 Thin-walled steel sheet 12 Degreasing liquid (treatment liquid) 13 Dipping roll 14 Degreasing treatment tank 15 Cleaning liquid 16 Cleaning tank 17 Ringer roll (liquid removing device) 18 Cleaning steel sheet 19 Component analyzer 20 Annealing furnace 21 Annealing steel sheet 22 Plating Equipment 23 Cold Rolled Coated Steel Sheet 30 Cold Rolled Coated Steel Sheet Manufacturing Equipment 31 Steam Cleaning Device 32 Ringer Roll (First Drainer) 33 Ringer Roll (Second Drainer)

Claims (5)

[Claims] 1. A thin steel sheet obtained by cold rolling is immersed in a treatment liquid to remove surface deposits, then immersed in a cleaning liquid, and this is used as a cleaning steel sheet. , Tin, chromium, etc., in a method for producing a cold-rolled plated steel sheet, wherein the sulfuric acid content and / or the chlorine content attached to the washed steel sheet are adjusted to adjust the sulfuric acid content and the chlorine content in the annealing treatment. And suppressing a reaction between the steel sheet and the washed steel sheet to prevent a surface defect occurring after the plating treatment. 2. A first draining device for draining the cleaning liquid adhering to the thin steel plate, wherein the sulfuric acid deposit amount and / or the chlorine deposit amount is blown to the thin steel plate after draining. The method for producing a cold-rolled plated steel sheet according to claim 1, wherein the adjustment is performed using a steam cleaning device to be attached and a second liquid draining device that drains the thin steel sheet taken out from the steam cleaning device. 3. The cleaning steel sheet has a sulfuric acid content of 0.7 m.
The method for producing a cold-rolled plated steel sheet according to claim 1, wherein the method is controlled to be not more than g / m ² . 4. The cleaning steel sheet has a chlorine adhesion amount of 1.4 m.
g / m < ² > or less.
The method for producing a cold-rolled plated steel sheet according to any one of the above. 5. The steel sheet according to claim 1, wherein the cold-rolled steel sheet is a steel sheet for beverage cans.
The method for producing a cold-rolled plated steel sheet according to the above item.