JPS5831399B2 - Manufacturing method of tinned steel plate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the production of tin-plated steel sheets with excellent ironing workability.

In recent years, DI cans (Drawn and Ironed Can5) have been used for cans of carbonated drinks, beer, aerosols, etc.
Seamless cylindrical containers, called cylindrical containers, are increasingly being used.

Initially, aluminum DI cans were the main product, but steel DI cans are gradually increasing.

Traditionally, steel cans have mainly been so-called three-piece cans with a top and bottom on a body joined by soldering, adhesive, or welding, but DI cans have a body and bottom formed by deep drawing and ironing. It is a two-piece can with a lid attached to the can.

With two-piece cans, there is no risk of leakage of the contents that can occur at the joints of three-piece cans, and since there are no seams on the body, it is possible to print the entire can, giving it a better appearance. Since aluminum DI cans can be made thinner than aluminum DI cans, material costs can be reduced.On the other hand, the material cost of aluminum DI cans is higher than that of steel DI cans. The number of steel DI cans is likely to increase in the future.

When manufacturing DI cans using tin-plated steel sheets, tin exhibits excellent lubrication during the drawing and ironing processes. When the temperature of the can rises above the melting point of tin due to the heat generated by the friction between the die and punch and the side walls of the can, unsightly, dull areas called reflow marks form on the side walls of the can, causing the can to deteriorate. damage the product value.

These reflow marks not only deteriorate the appearance of the can, but tin-plated steel sheets that are prone to such flow marks are undesirable because they put extra load on the ironing machine and shorten the life of dies and punches.

In order to reduce material costs in the future, the side walls of DI cans will tend to become thinner and thinner, and the degree of processing will increase accordingly.

Furthermore, in order to increase productivity, the ironing speed is expected to increase from the current 120 cans per minute to about 200 cans per minute in the future.

From either point of view, reflow marks are likely to occur.

Furthermore, in terms of the amount of spotting, in order to reduce costs,
The amount of sparrowing currently used is 8.479/r
Instead of rr' or 5,6ji/m2 tinned steel plate,
It is thought that tin-plated steel sheets with a plating amount of 2.8 g/m" or less will be used, but as this happens, it will be difficult to suppress the occurrence of flow marks with regular tin-plated steel sheets. It gets more and more difficult.

As a way to suppress the occurrence of reflow marks, countermeasures can be considered in terms of can manufacturing, such as increasing the amount of coolant in the ironing process or forcibly cooling the coolant, but can manufacturing costs will be reduced accordingly. Therefore, improvement of tin-plated steel sheets is strongly desired by can manufacturers.

On the other hand, Modern Packaging
-ging) On page 67 of the October 1972 issue, “
Compared to the tin-plated steel plate with a tin-layer melting process used in the production of regular three-piece cans, the matte-finish tin-plated steel plate is more prone to overheating of tools and causing unsightly flow marks. ``The tendency is small,'' and a patent related to this has also been published (Japanese Patent Publication No. 12578/1978).

However, even matte-finished tinned steel sheets cannot completely prevent the occurrence of reflow marks, and from this point of view as well, there is a strong demand for the development of even better tinted steel sheets.

In response to the above-mentioned demands, the present invention aims to provide a method for producing a tin-plated steel plate that is less likely to generate reflow marks and has excellent formability, especially during high-speed ironing.

The applicant has already published JP-A-49-73340°, JP-A-49-104844, and JP-A-50-4576.5 regarding the manufacturing method of tinned steel sheets with excellent ironing workability.
However, it reduces the occurrence of reflow marks,
As a result of further studies on various ways to improve formability, we found that by treating the surface of low-carbon cold-rolled steel sheets before annealing and then annealing, we could reduce the occurrence of reflow marks inexpensively and effectively. Developed a method to improve sex.

The present invention will be explained in detail below.

After electrolytically degreasing and cleaning cold-rolled low carbon steel, an aqueous solution or suspension containing one or more of Ca, Ti, Mn, Ni, B, and Al compounds is applied to the surface, After that, box-type annealing or continuous annealing is performed at a temperature higher than the recasting temperature, and Ca and Ti are deposited on the steel plate.

Mn, Ni, B, A6 (7) 1 or 2
Attach 0.1 to 60,711 fl/m'' of seeds or more.

After annealing, a tinned steel plate is produced through the same process as for manufacturing a normal tinned steel plate.

The tinned steel plate thus obtained had excellent ironing workability, suppressed the occurrence of reflow marks, and reduced ironing load.

Although soot is an excellent solid lubricant, the soot-steel interface contains Ca, Ti, and Mn that have undergone annealing treatment on the steel surface.

By interposing one or more of Ni, B, and Al as an intermediate layer, the lubricating properties of soot are further improved.

The amount of the intermediate layer in the soot and steel enclosure is 0.1 as metal.
If it is less than 7 ng/tri, the effect will be small, and if it exceeds 100 wj/m2, the intermediate layer itself will have an adverse effect.
00■/m2, preferably 0.1
~60 TIg/m'.

When two or more of the above-mentioned metals are included, the total may be within the above range.

As a method for applying the treatment liquid, any known method such as dipping, spraying, roll coating F or L may be used.

The annealing method is not particularly limited as long as it is a known recrystallization annealing method.

Examples will be specifically described below.

Example 1 A low carbon steel plate (thickness 0.325W) that had been degreased and cleaned after cold rolling and before recrystallization annealing was immersed in the treatment liquid shown in Table 1, squeezed with a rubber roll, and then heated in a mildly reducing atmosphere (N2 :93%,
Annealing was carried out at 675° C. for 10 hours.

Thereafter, it was subjected to temper rolling with an elongation rate of 1.0%, electrolytically cleaned in 5% caustic soda, immersed in 3% sulfuric acid, and then 5.6 j! /m sparrow was applied.

The ironing workability of this tinned steel plate was evaluated by the following method.

First, each sample was punched into a disk with a diameter of 138.9 g.
After deep drawing with a 9.5w punch to form a cup, the diameter is 65.4mm. Using a punch, adjust the clearance between the die and the punch to 0.25 mm for the first stage and 0.25 mm for the second stage.
It was ironed to a thickness of 16 mm and a third step of 0.10.

The rubbing speed was 160 cans per minute.

The occurrence of glue flow marks at this time is as shown in Table 1.

In this example, samples A1 to A6 are found to be more effective in suppressing reflow marks than sample A7 (comparative material).

Example 2 A steel plate similar to that in Example 1 was used, and after applying the treatment liquid shown in Table 2 before annealing, it was heated for 650' in the same atmosphere as in Example 1.
After annealing at C for 6 hours and adjusting the surface in the same manner as in Example 1, both surfaces were tinted at a rate of 1.12 g/m in a known acidic tinting bath.

This tin plated steel plate has a diameter of 125.5. A cup was formed by punching out a disk and deep drawing with a punch having a diameter of 67.9 m.

Using a punch with a diameter of 52.7 mm, the clearance between the die and the punch is 0.290 mm for the first stage and 0.180712 mm for the second stage. m, 3rd row 0.106111jn
The ironing process was performed with a clearance of .

The rubbing speed was 120 cans per minute.

After successively molding 100 cans of the same sample, the occurrence of external defects on the 100th can was observed, and the results are shown in Table 2.

As in this example, the amount of tinting is 1.12. ? /m'', a normal tin-plated steel plate (sample layer 15) subjected to tin layer melting treatment was prone to scratches and broke at the 50th can.

The matte-finished tin-plated steel plate (sample A14) that had not been subjected to the treatment of the present invention did not break, but many fairly deep scratches occurred.

In comparison, no flaws were observed in the tin-plated steel plates (samples A11 to A13) treated according to the present invention.

When the amount of tinting decreases in this way, the effect of the present invention becomes noticeable in suppressing external surface flaws related to breakage.

Example 3 Using the same steel plate as in Example 1, after applying the treatment liquid shown in Table 3, annealing in a weakly reducing atmosphere as in Example 1, and then treating sparrow as in Example 1. A steel plate was manufactured.

Ironing was performed in the same manner as in Example 1, and the ironing load was measured.

The results are shown in Table 3, and the ironing load of the tinted steel plate treated according to the present invention (sample points 21 to 22) was higher than that of the tinted steel plate not treated according to the present invention (sample A23). low.

As is clear from Example 1 above, the tin-plated steel sheet treated according to the present invention has a great effect in suppressing the occurrence of glue flow marks during ironing.

This not only improves the appearance of the can, but also because the ironing load is low as shown in Example 3, the load on the ironing machine is small and the tool life can be extended.

Further, as shown in Example 2, when the amount of plating is smaller than that of the tinned steel sheet currently used for ordinary DI cans, the tinned steel sheet according to the present invention is different from the tinned steel sheet not subjected to the treatment of the present invention. It exhibits good lubricity that cannot be obtained with other materials, suppresses the occurrence of external flow on the can, and prevents the can from breaking.

In addition, DI cans manufactured using the tinned steel sheet obtained by the treatment of the present invention have a D
It showed better corrosion resistance than the I can.

Claims (1)

[Claims] 1. In the manufacturing process of tinned steel sheets, Ca is added to the surface of low carbon cold rolled steel sheets that have been degreased and cleaned after cold rolling. 1 of the compounds Ti, Mn, Ni, B, or A6
An aqueous solution or suspension containing the species or two or more species is
, Ti, Mn, Ni, B, and A6 are coated on the steel in a total amount of 0.1 to 60 μ/d and annealed. Production method.