KR20230170643A - Substrate with sanding surface, manufacturing method thereof, and tin-plated sheet/chrome-plated sheet - Google Patents

Abstract

A method of manufacturing a substrate having a sanding surface includes providing a temper rolling mill including a first frame and a second frame, wherein the first frame includes opposingly installed first and third work rolls, and the second frame includes: It includes a second work roll and a fourth work roll installed oppositely, wherein the first work roll and the second work roll are located on the same side, the first work roll is an EDT roll, the second work roll is a grounding smooth surface roll, and the second work roll is a grounding smooth surface roll. The roughness of the surface of the first work roll is 1.6 to 2.2㎛, and the roughness of the surface of the second work roll is 0.35 to 0.75㎛; and forming a sanding surface on the first surface of the substrate by sequentially passing the substrate between the first work roll and the third work roll and between the second work roll and the fourth work roll. When the substrate having the sanding surface is processed into a necking can or an easy-open lid after undergoing tin plating or chrome plating, the plating layer at the necking point and the pre-scribing film point is not easily damaged and has excellent corrosion resistance.

Description

Substrate with sanding surface, manufacturing method thereof, and tin-plated sheet/chrome-plated sheet

The present invention relates to the field of metal material processing technology, and more specifically, to a substrate having a sanding surface, a manufacturing method thereof, and a tin-plated plate/chrome-plated plate.

Tin-plated/chrome-plated plates are widely used in beverage packaging, and are generally hot-rolled at a steel mill from a steel billet into a strip of about 2.0 mm, followed by acid rolling, annealing, temper rolling, tin plating/chrome plating, and passivation. It is manufactured from a tin-plated plate/chrome-plated plate, and then goes through an iron plate printing and can manufacturing process to produce cans, which are used to contain various beverages. Because the contents are acidic and high in protein, tin-plated/chrome-plated plate products must have high corrosion resistance.

Currently, the tin plate/chrome plate surface type selected for the necking can (Figure 1) or the easy-open lid (Figure 2) is R1 (fine stone pattern surface), the roughness Ra is 0.29 to 0.55 μm, and the plate surface pattern is stone. It has a pattern shape and a general wire-drawing feel (similar to a thin, shallow, short scratch to the naked eye), and when exposed to strong light, it exhibits a relatively light particle feel. However, necking cans or easy-open lids made of these tin-plated/chrome-plated plates are used at the necking point or pre-scribing film point (by scribing the film in advance at the target opening area after molding the easy-open lid, guides the opening direction) is easily corroded by the contents, so it can meet the corrosion resistance requirements.

The technical problem to be solved by the present invention is to provide a tin-plated plate/chrome-plated plate so that necking cans or easy-open lids made from the tin-plated plate/chrome-plated plate have excellent corrosion resistance and are not corroded by the contents. .

In order to solve the above technical problems, the present invention provides the following technical solutions.

A first aspect of the invention provides a method for manufacturing a substrate having a sanded surface, comprising the following steps:

Providing a temper rolling mill including a first frame and a second frame;

The first frame includes a first work roll and a third work roll installed oppositely, and the second frame includes a second work roll and a fourth work roll installed oppositely;

The first work roll and the second work roll are located on the same side, and the first work roll and the second work roll are used to contact the first surface of the substrate to form the sanding surface, wherein;

The first work roll is an Electro Discharge Texturing (EDT) roll, the second work roll is a grounding smooth surface roll, the roughness of the surface of the first work roll is 1.6 to 2.2 μm, and the roughness of the surface of the second work roll is 0.35 to 0.75 μm;

The substrate to be cold rolled is transferred to the temper rolling mill, so that the substrate sequentially passes between the first work roll and the third work roll and between the second work roll and the fourth work roll, and is attached to the first surface of the substrate. It includes; forming a sanding surface.

Furthermore, the rolling force of the first frame is 3500 to 4500 kN, and the rolling force of the second frame is 3500 to 4000 kN.

Furthermore, the roll replacement cycle of the first work roll and the second work roll is 120 ± 20 km, and the rolling tonnage is 150 ± 30 tons.

Furthermore, when the second surface of the substrate is a glossy surface, both the third work roll and the fourth work roll are ground smooth surface rolls, the roughness of the surface of the first work roll is 1.8 ± 0.2 μm, and the second work roll is a smooth surface. The roughness of the surface of the work roll is 0.70 ± 0.05 μm, the roughness of the surface of the third work roll is 0.70 ± 0.05 μm, the roughness of the surface of the fourth work roll is 0.40 ± 0.05 μm, and the rolling force of the first frame is The rolling force of the second frame is 3500 ± 100 kN, and the substrate is cold rolled by a temper rolling mill to form a glossy surface on the second surface.

Furthermore, when the second surface of the substrate is a fine stone surface, the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, and the roughness of the first work roll surface is 2.0 ± 0.2 μm. The roughness of the surface of the second work roll is 0.40 ± 0.05 μm, the roughness of the surface of the third work roll is 1.2 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.40 ± 0.05 μm, and the roughness of the surface of the first work roll is 0.40 ± 0.05 μm. The rolling force of the frame is 4000 ± 100 kN, and the rolling force of the second frame is 3500 ± 100 kN. After the substrate is cold rolled by a temper rolling mill, a fine stone pattern surface is formed on the second surface.

Furthermore, when the second surface of the substrate is a rough stone surface, the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, and the roughness of the first work roll surface is 2.0 ± 0.2 μm. The roughness of the surface of the second work roll is 0.40 ± 0.05 μm, the roughness of the surface of the third work roll is 1.5 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.70 ± 0.05 μm, and the roughness of the surface of the first work roll is 0.70 ± 0.05 μm. The rolling force of the frame is 4500 ± 100 kN, and the rolling force of the second frame is 4000 ± 100 kN. After the substrate is cold rolled by a temper rolling mill, a rough stone pattern is formed on the second surface.

A second aspect of the invention provides a substrate having a sanded surface manufactured using the manufacturing method according to the first aspect. One side of the substrate is a sanding surface, and the other side is a non-sanding surface. The sanding surface includes a shading pattern with dot-shaped irregularities and some filament-like lines located on the shading pattern. The shaded pattern and the filament-like line are distributed so that the roughness of the sanding surface is 0.05 to 0.80 μm.

Furthermore, the material of the substrate is MR-type, L-type, or D-type disk steel.

Furthermore, the non-sanded surface is a glossy surface, a fine stone surface, a rough stone surface, a silver surface, a rough silver surface, or a matte surface.

A third aspect of the present invention provides a tin-plated sheet, which is obtained by performing tin metal electroplating and reflow on the surface of the substrate according to the second aspect.

Furthermore, during tin metal electroplating, the concentration of divalent tin in the electroplating solution is 20 to 25 g/L, the concentration of methanesulfonic acid is 30 to 50 mL/L, and the concentration of antioxidant is 35 to 60 mL/L, The concentration of the additive is 20 to 30 mL/L, and during the electroplating process, the temperature of the electroplating solution is controlled to 38 to 45°C and the current density is controlled to 22 to 28A/mm ² .

Furthermore, during reflow, the reflow set temperature is 260 to 290°C, the reflow feedback temperature is 255 to 295°C, and the reflow output proportion is 30% to 50%.

Furthermore, one side of the substrate is a sanding surface, and the other side is a fine stone pattern surface.

A fourth aspect of the present invention provides a chrome plated plate, which is obtained by electroplating chromium metal and chromium oxide on the surface of the substrate according to the second aspect.

Furthermore, when electroplating chromium metal, the concentration of chromic anhydride in the electroplating solution is 140 to 160 g/L, the concentration of ammonium fluoride is 3 to 4 g/L, and during the electroplating process, the temperature of the electroplating solution is 36 to 40°C, the current density is controlled to be 50 to 80A/mm ² , the concentration of chromic anhydride in the first recovery groove is controlled to ≤50g/L, and the concentration of chromic anhydride in the second recovery groove is controlled to be ≤40g/L.

Furthermore, when electroplating chromium oxide, the concentration of chromic anhydride in the electroplating solution is 60 to 70 g/L, the concentration of ammonium fluoride is 1 to 2 g/L, and the concentration of sodium hydroxide is 8 to 10 g/L, During the electroplating process, the temperature of the electroplating solution is controlled to 31 to 35°C, the current density is controlled to 9 to 22A/mm ² , and the weight of the generated chromium oxide layer is controlled to 8 to 15 g/m ² .

Furthermore, one side of the substrate is a sanding surface, and the other side is a fine stone pattern surface.

A fifth aspect of the present invention provides a necking can, wherein the necking can is manufactured from the tin plate or chrome plate.

A sixth aspect of the present invention provides an easy-open lid, wherein the easy-open lid is manufactured from the tin plate.

Compared to the prior art, the beneficial effects of the present invention are as follows.

1. The present invention creatively proposes a new processing process for tin-plated/chrome-plated substrates, allowing the substrate to have two different surfaces, inner and outer, and forming a new surface type, a sanding surface, on the inner surface of the inner wall of the can. It is used to Its roughness is 0.50 to 0.80 μm, and its aesthetic appearance includes shaded patterns with dot-shaped irregularities and filament-like lines located on some of the shaded patterns. During the tin plating or chrome plating process on a substrate with such a sanding surface, the plating layer can be distributed more evenly on the substrate surface. Therefore, when the obtained tin-plated plate/chrome-plated plate is processed into a necking can or an easy-open lid, the plating layer at the necking point and the pre-scribing film point is not easily damaged and has excellent corrosion resistance, so it is not corroded by the contents. . Since the outer surface used to form the outer wall of the can can maintain its original surface shape, when the tin-plated/chrome-plated substrate manufactured by the present invention is fabricated to form various can packages, the visual characteristics of conventional can packages can be maintained. Therefore, marketing costs due to changes in new can packages can be avoided, and the substrate of the present invention can have stronger universality.

2. The present invention improves the conventional tin plating and chrome plating processes, and the new electroplating process improves the density of the tin plating layer and the chrome plating layer and the uniformity of alloy layer application, and reduces the void depth, so that the plating layer is attached to the substrate. It was able to protect the body well from heat and further improved the corrosion resistance of the board.

Figure 1 is a structural diagram of a necking can.
Figure 2 is a structural diagram of the easy-open lid.
Figure 3 is a plate pattern of the R1 surface as seen under a microscope.
Figure 4 is a plate pattern of the Rs surface as seen under a microscope.
Figure 5 is a schematic diagram of the wire drawing patterns of the R1 surface (a) and the Rs surface (b).
Figure 6 is a diagram showing the surface morphology of the tin layer on the substrate when using the conventional tin plating process (a) and the tin plating process (b) of the present invention.
Figure 7 shows the surface morphology of the alloy layer on the substrate when using the conventional reflow process (a, b, c) and the tin plating process (d, e, f) of the present invention.
Figure 8 is a surface morphology diagram of a chrome metal layer obtained using the chrome metal electroplating process of the present invention.
Figure 9 is a diagram showing the integrated surface morphology of the metal chromium layer and the chromium oxide layer obtained by adopting the chromium oxide electroplating process of the present invention.

Hereinafter, the present invention is described with reference to the accompanying drawings and specific examples so that those skilled in the art can better understand and practice the present invention, but the listed examples do not limit the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. The terms used in the specification of the present invention are for describing specific embodiments and are not intended to limit the present invention. As used herein, the term “and/or” includes any and all combinations of one or more associated listed items.

As explained in the background art, currently, the tin plated/chrome plated surface type selected for necking cans (Figure 1) or easy open lids (Figure 2) is R1 (fine stony surface), with a roughness Ra of 0.29 to 0.29. It is 0.55μm, the surface pattern is stone-like, has a general wire-drawing feel (similar to a thin, shallow, and short scratch to the naked eye), and exhibits a relatively light particle feel when exposed to strong light. However, necking cans or easy-open lids made of these tin-plated/chrome-plated plates do not meet the corrosion resistance requirements because the necking point or the pre-scribing film point is prone to corrosion by the contents during use.

Through long-term research, the inventor discovered that the main reason why necking points or pre-scribed film points are susceptible to corrosion by contents is the surface morphology of the tin-plated/chrome-plated substrate. In the prior art, since the content surface of the substrate is a fine stone pattern surface (R1), the surface has the shape of a wire drawing. Due to the presence of the wire drawing, a significant height difference appears on the substrate surface. As shown in FIG. 3, when observed under a microscope, a serious height imbalance appears at the wire drawing area, which appears as if valleys are distributed on the substrate surface.

Taking a tin-plated plate as an example, when tin is electroplated on such a substrate, if the tin deposition amount is constant, the tin plating amount in the protruding area on the substrate may be larger than the concave area due to the presence of wire drawing, thereby preventing uniform deposition of tin. It's a hindrance. During the reflow process, the tin deposited on the substrate melts and flows into the concave area, and then the concave area obstructs the further flow of the tin melt, preventing flattening after the tin melting and ultimately affecting the formation of the alloy layer. You can. Therefore, when tin is electroplated on a fine stone pattern surface, the distribution of the tin layer is uneven, and the tin content in the wire drawing area is significantly low. As a result, during the process of manufacturing cans or lids, during necking deformation or lid pre-scribing film, the relatively small tin layer of the wire drawing area itself is additionally damaged, and there is no tin layer to protect the substrate of the wire drawing area, Because it is directly exposed to the outside, the corrosion resistance of the wire drawing area is drastically reduced.

The same situation exists for chrome-plated plates. When electroplating chromium metal on the surface of a substrate, the pores on the surface of the plating layer are relatively small but take the form of deep pits. This is mainly because the chromium metal electroplating layer has a body-centered cubic structure, and is formed by preferred directional growth of the crystal lattice as the current density changes. The current efficiency of chrome plating is generally 20% to 25%, and since the side reaction is a hydrogen evolution reaction, the pores created by the chrome metal layer in the longitudinal direction are increased. Furthermore, wire drawing scratches exist along the longitudinal direction on the fine stony surface of the substrate, resulting in deeper longitudinal voids, which further reduces the deposition of chromium metal at the bottom of the wire drawing valley during the chrome electroplating process. The chromium oxide layer has a network and layered structure, and as the degree of corrugation increases, the protective function for the chrome metal layer further deteriorates and the corrosion resistance of the chrome-plated plate deteriorates.

Currently, in the can manufacturing industry, the substrate surface types of tin plated/chrome plated plates include B (glossy surface), R1 (fine stone surface), R2 (rough stone surface), S1 (silver surface), S2 (rough surface). There are silver surface) and M (matte surface), and the specifications and standards for each product type are listed in Table 1.

Table 1 Shape specifications and standards of conventional tin-plated/chrome-plated plate products

The inventors discovered that not all of the above surface shapes are suitable as inner surfaces of can and lid materials. In order to overcome the problem of tin-plated/chrome-plated plate corrosion in the prior art, the inventor studied and designed the surface form of a new tin-plated/chrome-plated substrate, which was defined as a sanding surface and denoted by Rs. As shown in Figure 4, when observed under a microscope, this Rs surface has shading patterns with dot-like irregularities and some filament-like lines located on the shading patterns. The shaded pattern and the filament-like line are distributed so that the roughness of the sanding surface is 0.50 to 0.80 μm. When observed under general light, there is a feeling of grain on the surface of Rs, which is relatively fine. Under strong light irradiation, there is a feeling of light and fine wire drawing, the gloss of the plate surface is slightly silvery, and the light reflection performance is relatively poor. As shown in FIG. 5, compared to the R1 surface, the drawing wire pattern of the Rs surface of the present invention is shorter and shallower, which reduces the degree of wire drawing (scratches), and the substrate corrugation caused by the wire drawing is used for the deposition and deposition of electroplated tin. In the reflow process, anything affecting the flattening of tin is removed, so the substrate surface is uniformly covered with a tin layer and alloy layer. Furthermore, because tin has excellent expansion properties, it ultimately increases the corrosion resistance of the deformation area during the process of manufacturing cans and lids.

The present invention provides a method for manufacturing a substrate with a sanding surface, and specifically includes the following steps.

Step (1) Provide a temper rolling mill. The temper rolling mill includes a first frame and a second frame. The first frame includes a first work roll and a third work roll installed opposite each other. The second frame includes opposingly installed second and fourth work rolls. The first work roll and the second work roll are located on the same side. The first work roll and the second work roll are used to contact the first surface of the substrate to form the sanding surface.

Here, the first work roll is an EDT (Electro Discharge Texturing) roll, and the second work roll is a grounding smooth surface roll. The roughness of the surface of the first work roll is 1.6 to 2.2 μm, and the roughness of the surface of the second work roll is 0.35 to 0.75 μm.

Step (2) Transfer the substrate to be cold rolled to the temper rolling mill, so that the substrate sequentially passes between the first work roll and the third work roll and between the second work roll and the fourth work roll, 1 Form the above sanding surface on the surface.

The EDT roll is a roll manufactured using EDT (Electro Discharge Texturing) technology, which creates pit-shaped burrs on the roll surface based on the EDT discharge principle, and forms particle shapes on the surface of the substrate by rolling the EDT roll. can be formed. The grounding smooth surface roll is formed on the roll surface based on a grinding process, and the shape of a wire drawing can be formed on the surface of the substrate by rolling the grounding smooth surface roll. In the present invention, by controlling the shape and roughness of the surfaces of the first work roll and the second work roll, the shape and roughness of the roll surface are printed on the surface of the substrate under the action of an externally applied rolling force, so that the sanding is performed on the surface of the substrate. A face shape is formed. Preferably, the rolling force applied by the first frame to the first work roll is 3500 to 4500 kN, and the rolling force applied by the second frame to the second work roll is 3500 to 4000 kN.

The first work roll and the second work roll must be replaced after being used for a certain period of time, and whether replacement is necessary can be determined according to the roll replacement cycle or rolling tonnage. Among them, the roll replacement cycle refers to the total length of the substrate rolled by the work roll, and the rolling tonnage refers to the total weight of the substrate rolled by the work roll. For example, a roll replacement cycle of 120 km means that after the work roll has rolled 120 km of substrate, work must be stopped and the roll replaced. Likewise, a rolling tonnage of 150 tons means that after the work rolls have rolled 150 tons of substrate, work must be stopped and the rolls replaced. In the present invention, the roll replacement cycle of the first work roll and the second work roll is preferably 120 ± 20 km, and the rolling tonnage is preferably 150 ± 30 tons.

Furthermore, the inventor abandoned the production manufacturing process of the conventional double-sided R1 side, used a new differentiated surface shape control, and the outer surface of the can still adopts the original R1 side, and the inner surface adopts the Rs side of the present invention. Thus, a differentiated type of substrate Rs/R1 was obtained. Through differentiated shape control (Rs content surface/R1 outer surface), the density and uniformity of the plating layer cover are improved during the electroplating process of the substrate, and deformation and cracking do not easily occur when the substrate expands and contracts, making the can Internal corrosion resistance is improved while also ensuring visibility outside the can. This Rs/R1 differentiated type substrate can be used to manufacture necking cans or easy-open lids after tin plating, and can be used to manufacture necking cans after chrome plating.

The substrate is a substrate material commonly used in the can manufacturing industry, and is preferably MR-type, L-type, or D-type disk steel.

The Rs/R1 differentiated type substrate can be manufactured by controlling the types of the third and fourth work rolls, surface roughness, and rolling force. Specifically, the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, the roughness of the surface of the first work roll is 2.0 ± 0.2 μm, and the roughness of the surface of the second work roll is 0.40 ± 0.40 μm. 0.05 μm, the roughness of the surface of the third work roll is 1.2 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.40 ± 0.05 μm, the rolling force of the first frame is 4000 ± 100 kN, and the second The rolling force of the frame is 3500 ± 100 kN, and after the substrate is cold rolled by a temper rolling mill, a fine stone pattern is formed on the second surface (R1).

Through the same method, differentiated types of substrates with different second surfaces can be obtained, for example, Rs/B substrates, Rs/R2 substrates, etc.

The manufacturing method of the Rs/B substrate is as follows: the third work roll and the fourth work roll are both ground smooth rolls, the roughness of the surface of the first work roll is 1.8 ± 0.2 μm, and the second work roll is The roughness of the roll surface is 0.70 ± 0.05 μm, the roughness of the third work roll surface is 0.70 ± 0.05 μm, the roughness of the fourth work roll surface is 0.40 ± 0.05 μm, and the rolling force of the first frame is 3500 ±100kN, the rolling force of the second frame is 3500±100kN, and the substrate is cold rolled by a temper rolling mill to form a glossy surface on the second surface (B).

The manufacturing method of the Rs/R2 substrate is as follows: the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, the roughness of the first work roll surface is 2.0 ± 0.2 μm, and the first work roll is an EDT roll. The roughness of the surface of the 2 work roll is 0.40 ± 0.05 μm, the roughness of the surface of the third work roll is 1.5 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.70 ± 0.05 μm, and the rolling force of the first frame is 4000 ± 100 kN, the rolling force of the second frame is 4000 ± 100 kN, and the substrate is cold rolled by a temper rolling mill to form a rough stone-patterned surface on the second surface (R2).

Table 2 shows in detail the roll arrangement method for manufacturing the several differentiated types of substrates.

Table 2 Temper rolling mill roll arrangement method for differentiated types of metal substrates

Of course, according to the different needs of downstream users, the same method may be used to manufacture various other differentiated types of substrates Rs/S1, Rs/S2s, and Rs/M, and the specific methods will not be repeated here.

In addition to the surface shape of the substrate, the effect of the electroplating process on the corrosion resistance performance of the tin-plated sheet/chrome-plated sheet cannot be ignored. Therefore, the present invention further studied the tin electroplating and reflow processes of the substrate.

Table 3 Conventional tin electroplating process parameters

As a result of observing the surface of the tin plating plate under a microscope, it can be seen that both the tin layer and the alloy layer are not densely covered on the surface of the substrate using the conventional tin electroplating process. As shown in Figure 6(a), the crystal grains of the tin layer are coarse and loose, and the gap between the crystal grains is large, so the corrosion resistance of the tin plate is poor. Therefore, in order to improve the corrosion resistance of a tin plated plate, the most important method is to improve the density of the tin layer and the covering power of the alloy layer.

In order to improve the conventional tin electroplating process, the inventor provided a new tin electroplating process, specifically as shown in Table 4. During tin metal electroplating, the concentration of divalent tin in the electroplating solution is 15 to 25 g/L, the concentration of methanesulfonic acid is 30 to 50 mL/L, the concentration of antioxidant is 35 to 60 mL/L, and the concentration of additives. is 25 to 30 mL/L. During the electroplating process, the temperature of the electroplating solution is controlled to 38 to 45°C and the current density is controlled to 22 to 28A/mm ² . Preferably, the concentration of divalent tin in the electroplating solution is controlled to 20 g/L, the concentration of methanesulfonic acid is controlled to 40 mL/L, the concentration of antioxidant is controlled to 45 mL/L, and the concentration of additives is controlled to 25 mL/L, The temperature of the electroplating solution is controlled at 42°C and the current density is controlled at 25A/mm ² .

Note that the antioxidant may be selected from oxidizing agents commonly used in the art, including but not limited to one or more of phenol, hydroquinone, resorcinol, and catechol. In the present invention, the antioxidant used is Quaker QUAKERTIN ^™ TPMW AOX antioxidant. The additives may be selected from additives commonly used in the art, including but not limited to one or more of surfactants and grain refiners. In the present invention, the additive used is Quaker QUAKERTIN ^™ Additive additive.

Table 4 Tin electroplating process parameters of the present invention

Tin plating is performed by adopting the improved electroplating process of the present invention, and the surface shape of the tin layer on the substrate is as shown in Figure 6(b). As can be seen from the figure, the tin layer has dense and fine crystal grains and the spacing between grains is small, which can better protect the substrate and improve the corrosion resistance of the substrate.

After tin electroplating, the uniformity of the tin plating layer can be improved by melting and flowing the tin layer through a reflow process to obtain an alloy layer. Table 5 lists conventional tin electroplating and reflow process parameters.

Table 5 Conventional tin electroplating and reflow process parameters

As shown in FIGS. 7(a) to 7(c), the crystal grains of the alloy layer formed by adopting a conventional reflow process are relatively fine, and thus the corrosion resistance is also relatively poor.

The present invention also improved the reflow process, specifically as shown in Table 6. During reflow, the height of the reflow box used is 3.5 to 5.5 m, the reflow set temperature is 260 to 290 ° C, the reflow feedback temperature is 255 to 295 ° C, and the reflow output proportion is 30% to 50%. Preferably, the height of the reflow box used is 4.5 m, the reflow set temperature is 270°C, the reflow feedback temperature is 275°C, and the reflow output proportion is 40%.

Table 6 Reflow process parameters of the present invention

The surface shape of the alloy layer obtained by adopting the reflow process of the present invention is as shown in Figures 7(d) to (f). As can be seen from the figure, the alloy layer crystal grains are coarse, columnar, and have excellent continuity, so corrosion resistance is also superior.

Furthermore, the present invention also studied the chrome plating process of the substrate.

As mentioned above, when performing chromium metal electroplating with conventional processes (as shown in Table 7), the crystal lattice prefers directional growth and the characteristics of the chrome plating process itself (current efficiency is low, typically 20%). to 25%, and the side reaction is a hydrogen evolution reaction), causing the chromium metal layer to create deep pit-shaped pores along the longitudinal direction. Therefore, improving the density of grains and reducing the void depth during the chromium metal deposition process is a major measure to improve the corrosion resistance of chrome plated sheets.

Table 7 Conventional chrome metal electroplating process parameters

The chromium metal electroplating of the present invention was also improved, as shown in Table 8. When electroplating chromium metal, the concentration of chromic anhydride in the electroplating solution is 140 to 160 g/L, the concentration of ammonium fluoride is 3 to 4 g/L, the concentration of chromic anhydride in the first recovery groove is ≤50 g/L, and the concentration of chromate in the second recovery groove is ≤50 g/L. The concentration of chromate anhydride in the groove is ≤40g/L. During the electroplating process, the temperature of the electroplating solution is controlled to 33 to 43°C and the current density is controlled to 25 to 100 A/mm ² . Preferably, when electroplating chromium metal, the concentration of chromic anhydride in the electroplating solution is 150 g/L, the concentration of ammonium fluoride is 3.5 g/L, the concentration of chromic anhydride in the first recovery groove is 30 g/L, and the concentration of chromate in the second recovery groove is 30 g/L. The concentration of chromic anhydride in the groove is 10g/L. During the electroplating process, the temperature of the electroplating solution is controlled to 38°C and the current density is controlled to 65A/mm ² .

Table 8 Chrome metal electroplating process parameters of the present invention

The surface shape of the chrome metal layer obtained by adopting the above chrome metal electroplating process is as shown in FIG. 8. As can be seen from the figure, a shallow pit depth and a dense chromium metal layer can be obtained through the electroplating process, and this type of chromium metal layer can better protect the substrate and improve corrosion resistance.

In the chromium electroplating process, the action between chromium metal and chromium oxide is reciprocal. That is, chromium oxide is produced at the same time that chromium metal is deposited, and chromium metal is also produced at the same time that chromium oxide is deposited, and they intersect with each other. As can be seen in Table 9, when performing chromium oxide electroplating by adopting a conventional process, the main components of the generated chromium oxide layer are Cr ₂ O ₃ , CrOOH, and Cr(OH) ₃ , and the surface pores are flat and Fine. It has a network, layered structure, and mainly serves to block the fine pores in the chromium metal layer. Therefore, by improving the density of the network structure of the chromium oxide layer, the corrosion resistance of the chrome plated plate can also be improved.

Table 9 Conventional chromium oxide electroplating process parameters

In order to improve the density of the chromium oxide layer network structure, the present invention improved the chromium oxide electroplating process, which is shown in Table 10. When electroplating chromium oxide, the concentration of chromic anhydride in the electroplating solution is 60 to 70 g/L, the concentration of ammonium fluoride is 1 to 2 g/L, and the concentration of sodium hydroxide is 6 to 12 g/L, and during the electroplating process, , the temperature of the electroplating solution is controlled at 27 to 37°C, the current density is controlled at 9 to 22A/mm ² , and the weight of the chromium oxide layer produced is controlled at 8 to 15 g/m ² . Preferably, when electroplating chromium oxide, the concentration of chromic anhydride in the electroplating solution is 65 g/L, the concentration of ammonium fluoride is 1.5 g/L, and the concentration of sodium hydroxide is 9 g/L, and during the electroplating process, The temperature of the electroplating solution is controlled to 32°C, the current density is controlled to 19A/mm ² , and the weight of the generated chromium oxide layer is controlled to ≥10g/m ² .

Table 10 Chromium oxide electroplating process parameters of the present invention

The integrated surface morphology of the metal chromium layer and the chromium oxide layer obtained by adopting the chromium oxide electroplating process is shown in FIG. 9. As can be seen from the drawing, the chromium oxide electroplating process according to the present invention helps improve the corrosion resistance of the chrome plated plate by forming a dense network chromium oxide layer.

In summary, the present invention provides a new tin-plated/chrome-plated substrate with a surface shape Rs, and the substrate having this surface shape allows the distribution of the plating layer to be more uniform during the electroplating process, and is used in the necking can/easy-open lid manufacturing process. In this way, the plating layer at the necking point and the pre-scribing film point is not easily deformed or ruptured, improving the corrosion resistance of the necking can/easy open lid. Furthermore, the present invention can improve the corrosion resistance of necking cans/easy-open lids by improving the tin plating and chrome plating processes and improving the density of the plating layer.

The above-described embodiments are only preferred embodiments to completely explain the present invention, and the scope of protection of the present invention is not limited thereto. Any equivalent replacement or modification made by a person skilled in the art based on the present invention shall fall within the protection scope of the present invention. The scope of protection of the present invention is based on the claims.

Claims (20)

In the method of manufacturing a substrate having a sanding surface,
The following steps,
Providing a temper rolling mill including a first frame and a second frame;
The first frame includes a first work roll and a third work roll installed oppositely, and the second frame includes a second work roll and a fourth work roll installed oppositely;
The first work roll and the second work roll are located on the same side, and the first work roll and the second work roll are used to contact the first surface of the substrate to form the sanding surface, wherein;
The first work roll is an Electro Discharge Texturing (EDT) roll, and the second work roll is a grounding smoothing roll; The roughness of the surface of the first work roll is 1.6 to 2.2 μm, and the roughness of the surface of the second work roll is 0.35 to 0.75 μm;
The substrate to be cold rolled is transferred to the temper rolling mill, so that the substrate sequentially passes between the first work roll and the third work roll and between the second work roll and the fourth work roll, and is attached to the first surface of the substrate. A method of manufacturing a substrate having a sanding surface, comprising: forming a sanding surface. According to paragraph 1,
A method of manufacturing a substrate having a sanding surface, characterized in that the rolling force of the first frame is 3500 to 4500 kN, and the rolling force of the second frame is 3500 to 4000 kN. According to paragraph 1,
A method of manufacturing a substrate having a sanding surface, characterized in that the roll replacement cycle of the first work roll and the second work roll is 120 ± 20 km, and the rolling tonnage is 150 ± 30 tons. According to paragraph 1,
When the second surface of the substrate is a glossy surface, both the third work roll and the fourth work roll are ground smooth surface rolls, the roughness of the first work roll surface is 1.8 ± 0.2 μm, and the second work roll surface The roughness of the third work roll surface is 0.70 ± 0.05 μm, the roughness of the fourth work roll surface is 0.40 ± 0.05 μm, and the rolling force of the first frame is 3500 ± 100 kN. and the rolling force of the second frame is 3500±100kN; A method of manufacturing a substrate with a sanded surface, characterized in that the substrate is cold rolled by a temper rolling mill and then a glossy surface is formed on the second surface. According to paragraph 1,
When the second surface of the substrate is a fine stone surface, the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, the roughness of the first work roll surface is 2.0 ± 0.2 μm, and The roughness of the surface of the second work roll is 0.40 ± 0.05 μm, the roughness of the surface of the third work roll is 1.2 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.40 ± 0.05 μm, and the rolling of the first frame The force is 4000 ± 100 kN, the rolling force of the second frame is 3500 ± 100 kN, and the substrate is cold rolled by a temper rolling mill, and then a sanding surface characterized in that a fine stone pattern is formed on the second surface. A method of manufacturing a substrate having a. According to paragraph 1,
When the second surface of the substrate is a rough stone surface, the third work roll is an EDT roll, the fourth work roll is a grounding smooth surface roll, the roughness of the first work roll surface is 2.0 ± 0.2 μm, and The roughness of the surface of the second work roll is 0.40 ± 0.05 μm, the roughness of the surface of the third work roll is 1.5 ± 0.2 μm, the roughness of the surface of the fourth work roll is 0.70 ± 0.05 μm, and the rolling of the first frame The force is 4500 ± 100 kN, the rolling force of the second frame is 4000 ± 100 kN, and the substrate is cold rolled by a temper rolling mill, and then a sanding surface characterized in that a rough stone pattern is formed on the second surface. A method of manufacturing a substrate having a. In the substrate having a sanded surface manufactured using the manufacturing method according to any one of claims 1 to 6,
One side of the substrate is a sanding surface, and the other surface is a non-sanding surface, and the sanding surface includes a shaded pattern with point-shaped irregularities and a filament-like line partially located on the shaded pattern, and the shaded pattern and the filament A substrate having a sanding surface, characterized in that the mold line distributes the roughness of the sanding surface to be 0.05 to 0.80 μm. In clause 7,
A substrate having a sanding surface, characterized in that the material of the substrate is MR-type, L-type, or D-type disk steel. In clause 7,
A substrate having a sanding surface, wherein the non-sanding surface is a glossy surface, a fine stone pattern surface, a rough stone pattern surface, a silver surface, a rough silver surface, or a matte surface. In the tin plate,
The tin-plated plate is obtained by performing tin metal electroplating and reflow on the surface of the substrate according to claim 7. According to clause 10,
During tin metal electroplating, the concentration of divalent tin in the electroplating solution is 20 to 25 g/L, the concentration of methanesulfonic acid is 30 to 50 mL/L, the concentration of antioxidant is 35 to 60 mL/L, and the concentration of additives. is 20 to 30 mL/L, and during the electroplating process, the temperature of the electroplating solution is controlled to 38 to 45°C and the current density is controlled to 22 to 28A/mm ² . According to clause 10,
When reflowing, the reflow set temperature is 260 to 290°C, the reflow feedback temperature is 255 to 295°C, and the reflow output proportion is 30% to 50%. According to any one of claims 10 to 12,
A tin-plated plate, characterized in that one side of the substrate is a sanding surface, and the other side is a fine stone pattern surface. In the chrome plated plate,
The chrome plated plate is obtained by electroplating chromium metal and chromium oxide on the surface of the substrate according to claim 7. According to clause 14,
When electroplating chromium metal, the concentration of chromic anhydride in the electroplating solution is 140 to 160 g/L, and the concentration of ammonium fluoride is 3 to 4 g/L; In the electroplating process, the temperature of the electroplating solution is 36 to 40℃, the current density is 50 to 80A/mm ² , the concentration of chromic anhydride in the first recovery groove is ≤50g/L, and the anhydride in the second recovery groove is ≤50g/L. A chrome-plated plate characterized in that the chromic acid concentration is controlled to ≤40g/L. According to clause 14,
When electroplating chromium oxide, the concentration of chromic anhydride in the electroplating solution is 60 to 70 g/L, the concentration of ammonium fluoride is 1 to 2 g/L, and the concentration of sodium hydroxide is 8 to 10 g/L, and the electroplating process , the temperature of the electroplating solution is controlled to 31 to 35°C, the current density is controlled to 9 to 22A/mm ² , and the weight of the resulting chromium oxide layer is controlled to 8 to 15 g/m ² . According to any one of claims 14 to 16,
A chrome-plated plate, characterized in that one side of the substrate is a sanding surface, and the other side is a fine stone pattern surface. In necking cans,
A necking can, characterized in that the necking can is manufactured from the tin plated plate according to claim 13. In necking cans,
A necking can, characterized in that the necking can is manufactured from the chrome plated plate according to claim 17. For the easy open lid,
The easy-open lid is characterized in that it is manufactured from the tin-plated plate according to claim 13.