KR101585710B1 - Patterning steel plate and method for patterning the same - Google Patents

Abstract

The present invention relates to a base steel sheet excellent in surface quality and plating adhesion with a pattern formed on its surface, and a hot-dip galvanized steel sheet comprising the same. According to another aspect of the present invention, there is provided a method of manufacturing a coated steel sheet, Masking the coating layer on the backing steel sheet with a patterning pattern; Exposing the base steel sheet having the masked coating layer formed thereon to ultraviolet rays; Heating the ground steel sheet exposed to ultraviolet rays; Etching the heated ground steel sheet; And removing the remaining coating layer. As a result, a pattern is formed and a ground steel sheet having excellent surface quality and plating adhesion can be obtained.

Description

BACKGROUND OF THE INVENTION Field of the Invention [0001] The present invention relates to a patterned steel plate and a method for patterning the same,

More particularly, the present invention relates to a base steel sheet having improved plating adhesion by increasing the contact area between Si and Mn and iron and zinc contained in the base steel sheet, And a method of processing the patterned steel sheet.

In order to use the hot-dip galvanized steel sheet for automobile parts which require weight reduction and stability, high strength and corrosion resistance are required. The steel sheet thus developed has been mainly made of a transformed structure to increase the strength (hereinafter referred to as AHSS steel), and mainly contains Si and Mn in a large amount. Si and Mn are easily used to fabricate a textured steel. However, in the case of producing a hot-dip galvanized steel sheet in order to secure corrosion resistance, Si and Mn are concentrated on the surface of the steel sheet during annealing to form an oxide, thereby deteriorating wettability in zinc plating.

As a method for solving this problem, US Patent Publication No. 2006-0108032 improves plating ability by adding Cr to a zinc plating bath. However, when Cr is added to the plating bath, there is a problem that Cr forms an oxide layer on the surface of the base steel sheet to generate dross.

In U.S. Patent Application Publication No. 2008-0053576, Ni is added to steel to suppress the surface enrichment of Si and Mn through internal oxidation of Ni during annealing to secure plating ability. However, the addition of Ni in the steel has a problem that the manufacturing cost is increased because the added element is expensive.

In addition, in US-A-6913658, the dew point of the annealing furnace is controlled to secure the plating property. However, this method is difficult to control the dew point of the annealing furnace, and has a problem that can cause surface oxidation in other steel types. In addition, when these steel grades are manufactured by galvannealed hot dip galvanizing, the alloying temperature is increased due to oxides of Si or Mn concentrated on the surface. If the alloying temperature increases, residual austenite or martensite structure must remain in the AHSS steel after alloying, but the alloying temperature will increase and these will transform into ferrite or bainite structures. In this case, there arises a problem that proper strength and toughness can not be secured.

Korean Patent Publication No. 2010-0046072 discloses a method of reducing iron oxide in a reducing atmosphere and performing plating when the steel is oxidized before annealing and then annealed. However, this method has problems in manufacturing due to difficulty in managing the oxide layer thickness. Also, there is a problem that Si or Mn is concentrated on the oxidized layer before annealing, and plating peeling occurs after hot dip galvanizing.

Japanese Unexamined Patent Application Publication No. 2005-200690 discloses a technique in which a metal such as Ni is annealed after annealing and cooling a base steel sheet, and Mn, Si, or Al oxide on the surface generated at the time of annealing is covered with the metal coating layer . However, in the case of Ni, there is a problem that surface selective oxidation of Si or Mn contained in the base steel sheet can not be suppressed due to the alloying reaction with the base steel sheet in the heat treatment process.

In the present invention, the surface of the base steel sheet is subjected to a patterning treatment to increase the contact area between Si and Mn contained in the base steel sheet and the iron and zinc, thereby improving the plating adhesion without causing unplated coating.

The present invention provides a base steel sheet excellent in surface quality and plating adhesion with a pattern formed on its surface.

The pattern may be polygonal or circular. The polygon may be selected from the group consisting of a triangle, a rectangle, a pentagon, and a hexagon.

The present invention may also include a hexagonal pattern having a length of one side on the surface of 0.5 to 2.5 占 퐉, a total size of 1 to 5 占 퐉, a depth of 1 to 25 占 퐉, and a ratio of total size to depth of 1 to 5 on the surface.

Said hexagonal pattern comprising two circular patterns therein; The two circular patterns may each have a diameter of 0.1 to 0.6 탆, 0.3 to 1.7 탆, and a depth of 0.5 to 1 times the depth of the regular hexagon.

The present invention also relates to the above-mentioned base steel sheet; And a hot-dip galvanized layer formed on the base steel sheet.

According to another aspect of the present invention, there is provided a method of manufacturing a coated steel sheet, Masking the coating layer on the backing steel sheet with a patterning pattern; Exposing the base steel sheet having the masked coating layer formed thereon to ultraviolet rays; Heating the ground steel sheet exposed to ultraviolet rays; Etching the heated ground steel sheet; And removing the remaining coating layer.

The coating layer may have a thickness of 0.1 to 10 mu m.
The masking may be performed using at least one selected from the group consisting of chromium, nickel, and stainless steel.

The ultraviolet ray may have a wavelength of 10 nm to 400 nm.

Also, the ultraviolet ray exposure may be performed for 10 seconds to 100 seconds.

The heating is preferably performed at 120 to 180 ° C for 10 to 100 seconds.

Further, the etching may be performed using a hydrochloric acid or sulfuric acid solution, and the solution may have a mass percentage concentration of 5 to 20.

According to the present invention, by increasing the contact area between iron and zinc while suppressing surface enrichment of Si or Mn contained in the base steel sheet by patterning the surface of the base steel sheet, the plating adhesion can be improved without causing unplated have.

1 is a schematic view showing a patterning processing method according to the present invention.
2 is a schematic view showing the shape of a patterning according to the present invention.
Fig. 3 is a graph showing the results of measurement of the surface roughness of the surface of a steel sheet obtained by the conventional hot-dip galvanized steel sheet (length of one side of a regular hexagonal pattern of 2.5 mu m, total size of 5 mu m, depth of 15 mu m, size to depth ratio of 3, diameter of an outer circular pattern of 1.67 mu m, 탆, hexagonal depth to circular depth ratio 1.0).
Fig. 4 is a graph showing the relationship between the diameter of the inner circular pattern and the diameter of the outer circular pattern of the comparative example (the length of one side of a regular hexagonal pattern is 2.5 mu m, the total size is 5 mu m, the depth is 15 mu m, 탆, hexagonal depth to circular depth ratio 0.4).

The present invention relates to a base steel sheet excellent in surface quality and plating adhesion and a manufacturing method thereof. According to one embodiment of the present invention, there is provided a base steel sheet having a pattern formed on its surface and excellent in surface quality and plating adhesion.

The base steel sheet is not particularly limited as long as it is commonly used, but it is preferable to use a cold-rolled steel sheet.

In order to improve the wettability of the base steel sheet, it is necessary to have a large amount of anchoring areas as well as a reaction area between the molten zinc and the base steel sheet. Accordingly, in the present invention, by forming a pattern on the surface of the base steel sheet, the bonding area between the molten zinc and the base steel sheet can be increased to improve the wettability, thereby increasing the anchoring area between the base steel sheet and the molten zinc. The method of forming the pattern is not particularly limited as long as it is a commonly used method, but micro patterning and nanopatterning can be used.

The pattern may be polygonal or circular. In addition, the polygon may be in the shape of a triangle, a rectangle, a pentagon, a hexagon, or the like. The hexagonal shape is most preferable. The adhesion of the surface of the base steel sheet can be improved through the regular hexagonal pattern.

Preferably the pattern comprises a hexagon and a circle, more preferably the pattern comprises a first circular pattern within a hexagonal pattern and a second circular pattern having a smaller diameter inside the first circular pattern. In the present invention, it is preferable that the pattern is formed in the form of a concave portion.

According to another embodiment of the present invention, the base steel sheet of the present invention comprises a base steel sheet having a length of one side of 0.5 to 2.5 탆, a total size of 1 to 5 탆, a depth of 1 to 25 탆, May include a regular hexagonal pattern of 1 to 5.

As shown in FIG. 2, the regular hexagonal pattern preferably has a length of 0.5 to 2.5 μm on one side, a total size of 1 to 5 μm, a depth of 1 to 25 μm, and a ratio of the total size to the depth of 1 to 5.

When the size of one side of the hexagonal pattern is less than 0.5 mu m, the wettability of zinc is deteriorated due to the surface tension between the peaks of the pattern. When the thickness is more than 2.5 占 퐉, the wettability is lowered due to surface enrichment of Si and Mn.

If the total size of the hexagonal pattern is less than 1 mu m, the reactivity between the molten zinc and the base steel sheet is not improved, and the wettability of zinc is lowered due to the surface tension between the peaks of the pattern. When the thickness is more than 5 mu m, the wettability is lowered due to surface enrichment of Si and Mn.

In addition, when the depth of the regular hexagonal pattern is less than 1 mu m, the increase in the surface area is insignificant and the anchoring effect is not large. If it is more than 25 mu m, the patterning process time becomes longer.

Also, when the ratio of the total size to the depth is less than 1, the increase in the surface area is insignificant and the anchoring effect is not large. 5, there is a problem that the patterning processing time becomes long.

On the other hand, the hexagonal pattern may have a plurality of circular patterns therein. The number of the circular patterns is not particularly limited as long as the surface area can be increased, but it is preferable that the circular patterns have two circular patterns. The base steel sheet having a circular pattern in the hexagonal pattern further widens the bonding area with molten zinc and increases anchorable portions. As a result, the wettability of the base steel sheet is improved, and the adhesion with molten zinc is increased.

As shown in Fig. 2, the two circular patterns preferably have a diameter of 0.1 to 0.6 mu m, 0.3 to 1.7 mu m, and a depth of 0.5 to 1 times the depth of the regular hexagon.

If the diameter of the protruding pattern is less than 0.3 탆, it is difficult to disperse the surface thickening, which is an advantage of the prototype. If it exceeds 1.7 탆, interference with the regular pattern may occur. In addition, when the diameter is less than 0.1 탆, the plating adhesion of the base steel sheet deteriorates, and when the diameter exceeds 0.6 탆, interference with the circular pattern having a large diameter occurs.

The depth of the circular pattern is preferably 0.5 to 1 times the depth of the regular hexagon. If it is less than 0.5 times, adhesion with molten zinc due to capillary phenomenon is not smooth. If it is more than 1 time, there is a problem that molten zinc can not enter the inside of a regular hexagon due to surface tension, and is damaged during heat treatment.

The present invention also provides a method of manufacturing a steel sheet, And a hot-dip galvanized layer formed on the base steel sheet. The base steel sheet having the pattern formed thereon has a large contact area between the base steel sheet and the zinc sheet to improve the wettability of the base steel sheet and zinc although the Si or Mn contained in the base steel sheet is concentrated to the surface during the heat treatment. Accordingly, the hot-dip galvanized steel sheet including the base steel sheet has an advantage of improved plating adhesion and excellent plating property.

According to another embodiment of the present invention, there is provided a method of manufacturing a steel sheet, comprising: forming a coating layer on a steel sheet; Masking the coating layer on the backing steel sheet with a patterning pattern; Exposing the base steel sheet having the masked coating layer formed thereon to ultraviolet rays; Heating the ground steel sheet exposed to ultraviolet rays; Etching the heated ground steel sheet; And a step of removing the remaining coating layer

Best Mode for Carrying Out the Invention Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. The shape and size of elements in the drawings may be exaggerated for clarity.

1 is a schematic view showing a patterning processing method according to the present invention.

First, a coating layer is formed on the base steel sheet (1). The coating layer is coated with a photoresist material for patterning processing. As the photoresist material, PMMA (polymethyl methacrylate), PMGI (polymethyl glutarimide), SU-8, or the like may be used.

The coating layer is dried or heated to volatilize the solvent present in the coating layer. The volatilized steel sheet is exposed to ultraviolet light (UV) using a patterned mask (2). The coating layer on the surface of the base steel sheet exposed to ultraviolet rays is cured and the masked coating layer on the surface of the base steel sheet not exposed to ultraviolet rays is not cured. The material used for the masking is not particularly limited as long as it is a material commonly used for masking, but a metal can be used, and chromium, nickel and stainless steel can be used.

The ultraviolet ray may have a wavelength of 10 nm to 400 nm. If the wavelength is less than 10 nm, scum may be generated in the coating layer. If the wavelength is more than 400 nm, the polymer is not sufficiently interconnected in the coating layer, and even if exposed to ultraviolet rays, the coating is not sufficiently cured.

The exposure time of the ultraviolet rays is preferably 10 to 100 seconds. In the case of less than 10 seconds, interconnection of the polymer in the coating layer does not occur sufficiently, and even if exposed to ultraviolet rays, it is not cured sufficiently, and if it exceeds 100 seconds, it may cause scum on the coating layer.

The base steel sheet exposed to ultraviolet rays is heated (3). The coated steel sheet exposed to ultraviolet rays is heated to 120 to 180 ° C to sufficiently cure the coating layer. The heating is preferably performed at 120 to 180 ° C for 10 to 100 seconds. More preferably 140 deg. C is preferable. If the amount is less than the above range, it is not sufficiently cured and the pattern may be lost during washing. If the amount exceeds the above range, pudding may occur in the coating layer. When the coated steel sheet is melted with a printing solution such as a Stoddard solvent mixture, the UV-cured coating layer remains and the UV-uncoated coating layer is removed.

In the next step, the base steel sheet thus treated is etched (4). The etching is not particularly limited as long as it is a commonly used material, but it can be performed using hydrochloric acid, sulfuric acid, or the like. More preferably, hydrochloric acid or sulfuric acid having a mass percentage concentration of 5 to 20 can be used. If the zeolite percent concentration is less than 5, erosion of the uncoated portion will not occur sufficiently, and if the mass percent concentration is more than 20, erosion will occur excessively, causing damage to the steel sheet. When etching is performed, only the uncoated portion is eroded and the coated portion is present.

After the etching, the coating layer remaining on the base steel sheet is removed (5). When the coating layer remaining on the base steel sheet is removed, a desired pattern can be formed on the surface of the base steel sheet.

Hereinafter, the present invention will be described more specifically by way of specific examples. The following examples are provided to aid understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

The present invention relates to a steel sheet having a composition of 0.5 to 2 wt% of Si, 0.5 to 3 wt% of Mn, 0.01 to 0.1 wt% of Al, 0.001 to 0.05 wt% of P and 3 to 50 ppm of B, Cold-rolled steel sheets, which are inevitable impurities due to smelting, were used.

A regular hexagonal pattern was formed on the cold-rolled steel sheet. The length, total size, depth, size-to-depth ratio of one side of the hexagonal pattern are shown in Table 1 below. In addition, two circular patterns were formed in the hexagonal pattern. The diameters, depths, diameters and depth ratios of the circular patterns are shown in Table 1 below.

The cold-rolled steel sheet was patterned in the following manner.

First, the cold-rolled steel sheet was coated with SU-8, which is a photoresist material. A cold-rolled steel sheet having a coating layer formed of a photoresist material was masked with a patterning pattern using chromium. The masked cold-rolled steel sheet was irradiated with ultraviolet (UV) at 95 ° C to cure the photoresist material exposed to ultraviolet rays. Then, the coating layer was further cured by heating at 140 DEG C and a coating layer which was not cured was removed by using a printing agent. The cold-rolled steel sheet thus treated was etched with 10% hydrochloric acid to cause erosion only in the uncoated portion, so that the surface of the cold-rolled steel sheet was patterned. Finally, the coating layer remaining on the cold rolled steel sheet was removed to form a pattern.

The cold-rolled steel sheet subjected to the patterning treatment was maintained at an annealing temperature of 800 ° C for 60 seconds, and the atmosphere was maintained at a hydrogen concentration of 5% and a dew point temperature of -40 ° C. The heat-treated cold-rolled steel sheet was dipped in a zinc plating bath containing 0.13 to 0.2 wt% of Al for 4 seconds to perform hot-dip plating.

The cold-rolled steel sheet, which was hot-dip galvanized, was subjected to naked-eye observation, and the adhesion of the coating was evaluated by bending test.

The appearance of the surface was visually observed after the hot dip coating. In the case of unplated, it is marked as defective, and in the case where unplated is not occurred, it is marked as good.

Adhesion was evaluated by taping after bending test and the presence or absence of peeling of the plating. In the case of peeling of the plating, it was marked as defective, and in the case of no peeling of the plating, it was marked as good.

Workability was judged based on the time required for the patterning process (20 seconds). If it exceeds 20 seconds, it is marked as bad, and when it is 20 seconds or less, it is marked as good.

The evaluation results according to the respective conditions are shown in detail in Table 1 below.

Hexagonal shape Circular shape Properties Length of one side size depth Size vs. depth ratio Outer circle
diameter Inner circle
diameter Hexagon Depth to Round Depth Exterior Adhesiveness Workability Remarks 0.4 0.8 0.64 0.8 0.27 0.09 0.4 Bad Bad Good Comparative Example 0.5 1.0 1.2 0.8 One 0.27 0.09 0.4 0.5 1.0 1.2 2.4 3 0.27 0.09 0.4 0.5 1.0 1.2 4 5 0.27 0.09 0.4 0.5 1.0 1.2 4.8 6 0.27 0.09 0.4 Bad 0.5 1.0 1.2 0.5 One 0.8 0.8 0.33 0.11 0.4 Bad Bad Good Comparative Example 0.5 1.0 1.2 One One 0.33 0.11 0.4 Bad Bad Good Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 3 3 0.33 0.11 0.4 Bad Bad Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 5 5 0.33 0.11 0.4 Bad Bad Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 6 6 0.33 0.11 0.4 Bad Bad Bad Comparative Example 0.5 Good Good 1.0 1.2 Bad Bad 2.5 5 4 0.8 1.67 0.56 0.4 Bad Bad Good Comparative Example 0.5 1.0 1.2 5 One 1.67 0.56 0.4 Bad Bad Good Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 15 3 1.67 0.56 0.4 Bad Bad Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 25 5 1.67 0.56 0.4 Bad Bad Comparative Example 0.5 Good Good Honor 1.0 1.2 Bad Bad Comparative Example 30 6 1.67 0.56 0.4 Bad Bad Bad Comparative Example 0.5 Good Good 1.0 1.2 Bad Bad 3 6 4.8 0.8 2.00 0.67 0.4 Bad Bad Good Comparative Example 0.5 1.0 1.2 6 One 2.00 0.67 0.4 0.5 1.0 1.2 18 3 2.00 0.67 0.4 0.5 1.0 1.2 30 5 2.00 0.67 0.4 0.5 1.0 1.2 36 6 2.00 0.67 0.4 Bad 0.5 1.0 1.2

As shown in Table 1, the hexagonal pattern had the best appearance, adhesion, and workability when the overall size was 1 to 5 탆. Also, when the depth of the regular hexagonal pattern was 1 to 5 times the total size, the best appearance of the surface, adhesion, and workability were exhibited.

Also, the two circular patterns formed in the regular hexagonal pattern have the best appearance when the diameter is 0.1 to 0.67 mu m, 0.3 to 1.7 mu m, and the depth is 0.5 to 1 times the depth of the regular hexagon, appear.

Claims (14)

delete delete delete A polygonal pattern having a length of one side on the surface of 0.5 to 2.5 占 퐉, a total size of 1 to 5 占 퐉, a depth of 1 to 25 占 퐉 and a ratio of total size to depth of 1 to 5,
Wherein the polygon is at least one selected from the group consisting of a triangle, a rectangle, a pentagon and a hexagon, and has excellent surface quality and plating adhesion. 5. The method of claim 4, wherein the polygonal pattern comprises two circular patterns therein;
Wherein the two circular patterns each have a diameter of 0.1 to 0.6 탆, 0.3 to 1.7 탆, and a depth of 0.5 to 1 times the depth of the polygon, respectively, and are excellent in surface quality and plating adhesion. The base steel sheet of claim 4 or 5; And a hot-dip galvanized layer formed on the upper portion of the steel strip. Forming a coating layer on the steel sheet;
Masking the coating layer on the backing steel sheet in a polygonal pattern;
Exposing the base steel sheet having the masked coating layer formed thereon to ultraviolet rays;
Heating the ground steel sheet exposed to ultraviolet rays;
Etching the heated ground steel sheet; And
Removing the remaining coating layer,
The polygon has a length of one side of 0.5 to 2.5 탆, a total size of 1 to 5 탆, a depth of 1 to 25 탆, a ratio of total size to depth of 1 to 5,
Wherein the polygon is at least one selected from the group consisting of a triangle, a rectangle, a pentagon, and a hexagon. 8. The patterning method according to claim 7, wherein the coating layer has a thickness of 0.1 to 10 mu m. 8. The method of claim 7, wherein the masking is performed using at least one selected from the group consisting of chromium, nickel, and stainless steel. 8. The patterning method according to claim 7, wherein the ultraviolet rays have a wavelength of 10 nm to 400 nm. 8. The method of claim 7, wherein the ultraviolet exposure is performed for 10 seconds to 100 seconds. 8. The method of claim 7, wherein the heating is performed at 120 to 180 DEG C for 10 to 100 seconds. 8. The method of claim 7, wherein the etching is performed using a hydrochloric acid or a sulfuric acid solution. 14. The method of claim 13, wherein the solution has a mass percent concentration of 5-20.

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