KR20210054712A - Zinc-plated steel sheet having excellent workability and method for manufacturing thereof - Google Patents

Abstract

Provided are a zinc-plated steel sheet, and a method for manufacturing the same. The zinc-plated steel sheet comprises a base steel sheet; and a zinc-plated layer provided on the base steel sheet. The zinc-plated steel sheet comprises fine pores inside the zinc-plated layer, and porosity of the zinc-plated layer is at least 4.3% based on a cross-sectional area.

Description

Zinc-plated steel sheet with excellent workability and its manufacturing method {ZINC-PLATED STEEL SHEET HAVING EXCELLENT WORKABILITY AND METHOD FOR MANUFACTURING THEREOF}

The present invention relates to a zinc-based plated steel sheet excellent in workability and a method of manufacturing the same.

Zinc and zinc alloy plated steel sheets by vacuum evaporation have a relatively small grain size compared to hot-dip or electroplated steel sheets. Accordingly, it has a beautiful exterior surface, it is possible to precisely control the amount of plating, so that economic efficiency can be secured through prevention of overplating, and it has characteristics that it can retain uniform physical properties over the entire width and the entire length due to excellent plating amount/composition uniformity. In addition, such a uniform plating amount makes it possible to improve the welding quality during welding such as lazer brazing, arc welding, etc. and improve productivity by increasing the working speed. In particular, the plating material of the vacuum deposition method is attracting attention as a plating method of various high-strength steels and ultra-high-strength steels as it can reduce or prevent Hydrogen Delayed Fracture.

However, since the crystal grains of the vacuum-deposited plating layer are very fine in the range of several to tens of micrometers (㎛), the ductility is relatively reduced, and accordingly, cracks in the plating layer may occur during processing, and in severe cases, problems such as peeling of the plating layer may occur. do.

On the other hand, due to the characteristics of the sacrificial method, when zinc and zinc alloy plating, which are the most representative plating materials in the steel industry, are formed by vacuum deposition, the above-described problem of cracking and peeling of the processed part may occur. In particular, in the case of zinc alloy, as various intermetallic compounds having excellent corrosion resistance in the plating layer are formed, the corrosion resistance is higher than that of pure zinc plating, but these intermetallic compounds have high brittleness, so that the problem of cracking and peeling of the processed part is more severe.

In order to solve this adhesion problem, in the prior art, in order to coat an inter-layer containing Al, Ti, etc. having good adhesion and ductility, or to limit the amount of formation of brittle intermetallic compounds, the total amount of alloying elements Additional processes, such as limiting or increasing ductility through tempering heat treatment, were applied.

However, in the case of the prior art as described above, there is a problem in that economic efficiency is poor because the number of processes increases or the production speed decreases, and there is a problem that sufficient corrosion resistance improvement is limited due to a decrease in the amount of alloying elements added.

The present invention solves the problem of cracking and peeling of the plated layer occurring during various processing due to the increase in hardness and brittleness of the plated layer due to grain refinement and formation of intermetallic compounds in the zinc and zinc alloy plated steel sheet manufactured by the vacuum deposition method. Has its purpose.

The subject of the present invention is not limited to the above description. Those of ordinary skill in the art to which the present invention pertains will not have any difficulty in understanding the additional subject of the present invention from the general details of the present specification.

An aspect of the present invention is a holding steel plate; And a zinc-based plating layer provided on the holding steel sheet, wherein the zinc-based plating layer includes micropores therein, and a porosity of the zinc-based plating layer may be a zinc-based plated steel sheet having a cross-sectional area of 4.3% or more.

The micropores may be located in at least one of an interface side region between the holding steel sheet and the zinc-based plating layer and an outermost surface side region of the zinc-based plating layer within the galvanized layer.

The zinc-based plating layer may be a zinc plating layer.

The zinc-based plating layer may be a zinc alloy plating layer including Zn and at least one of Mg, Al, and Ni.

The zinc-based plating layer may have a multilayer structure comprising a combination of two or more selected from a zinc plating layer and a zinc alloy plating layer including at least one of Zn and Mg, Al, and Ni.

The micropores may be located in at least one of an interface side region between the holding steel sheet and the zinc-based plating layer, an interface between the plating layer, and an outermost surface side region of the zinc-based plating layer within the galvanized layer.

The size of the micropores may be 50 ~ 500nm.

The porosity may be 4.3% or more and 18.0% or less.

Another aspect of the present invention is a method of manufacturing a galvanized steel sheet using a vacuum deposition method, comprising: preparing a holding steel sheet; Including, in the step of vacuum deposition by spraying metal vapor of zinc or zinc alloy on at least one surface of the holding steel sheet through a nozzle, at least a portion of the metal vapor is at least one surface of the holding steel sheet It may be a method of manufacturing a zinc-based plated steel sheet that is sprayed to have an incidence angle that is not perpendicular to

The vacuum deposition method may be an Electromagnetic Levitation Physical Vapor Deposition (EML-PVD) method, and a distance between the nozzle and the steel plate may be 6 cm or less (excluding 0 cm).

The distance between the nozzle and the holding steel plate may be 2 to 6 cm.

The nozzle may be a diffusion type nozzle having the same diameter at the inlet side and the outlet side or a larger outlet side diameter based on a nozzle cross section.

In the case of a diffusion type nozzle, the distance between the nozzle and the holding steel plate may be 10 cm or less (excluding 0 cm).

According to the present invention, it is possible to provide a zinc-based plated steel sheet having no cracking and peeling of the plating layer during processing and having excellent processing adhesion, and a method of manufacturing the same.

Various and beneficial advantages and effects of the present invention are not limited to the above description, and may be more easily understood in the course of describing specific embodiments of the present invention.

1 shows the spraying form in a general nozzle.
Figure 2 is a schematic diagram of an electromagnetic levitation physical vapor deposition (Electromagnetic Levitation Physical Vapor Deposition, hereinafter also referred to as'EML-PVD') type evaporation source that can be applied as an embodiment of the manufacturing method according to the present invention.
3 is a scanning electron microscope (SEM) photograph of a Zn-Mg plated steel sheet manufactured by the prior art and results of adhesion evaluation. (a) is a cross-sectional SEM photograph (×20000 magnification) of a Zn-Mg alloy plating layer plated by a conventional EML-PVD method. (b) is a photograph of the tape after the 0T bending test, and the dark part in the middle of the tape shows the part where the plating side was peeled off and buried. (c) is a photograph (×100 magnification) of the surface of the part where cracks and peeling occurred in the processed part of the Zn-Mg plated steel sheet, observed by SEM. In the photo, the bright part is the plating layer and the dark part is due to the peeling of the plating layer. It represents the exposed part of the steel plate.
4 is a cross-sectional (TEM) photograph of the Zn-Mg alloy plating layer according to the spray distance (TS, 2 to 16 cm). In Fig. 4, CR denotes a cold-rolled steel sheet.
5 is a graph showing the porosity (area %) and adhesion test results (peel width) of the plating layer according to the spray distance.
6 shows the results of the 0T bending test of the Zn-Mg alloy plated steel sheet according to the spray distance, and is a photograph taken of the tape after the 0T bending test. The dark part in the middle of the tape at the spraying distance of 8~16cm is the part where the plating layer was peeled off and the plating layer was buried on the tape, and in the case of the spraying distance of 2~6cm, the tape was folded and shaded due to wrinkles, but the actual plating layer No bleeding occurred.
7 is a photograph of a cross section of a Zn-Mg alloy plated steel sheet manufactured with a spray distance of 2 cm observed with a transmission electron microscope (TEM) (plating thickness of 4.1 μm). The lower left is the holding steel plate, the upper right is the surface portion of the plating layer, and the micropores are indicated by arrows.
8 is a comparison of the occurrence of cracking/peeling in the processed part according to the presence or absence of micropore formation in the vacuum-deposited pure galvanized galvanized steel sheet. (a) is a photograph observed through a scanning electron microscope (SEM) at a magnification ×300 of the surface of a conventional galvanized steel sheet without pore formation, and the dark part is a cracked part. (b) is a cross-sectional photograph of a focused ion beam (FIB) of a galvanized steel sheet having a porosity of 4.6% or more according to the present invention, and the dark part corresponds to the part in which micropores are formed. (c) is a photograph of the surface of the galvanized steel sheet having pores formed in accordance with the present invention observed through SEM at a magnification ×300, and unlike (a), a dark part where cracks occurred did not appear.
9 schematically shows a comparison of the spacing required for forming a sufficient porosity in the case of a general straight nozzle and a diffusion nozzle.

The terminology used herein is for reference only to specific embodiments and is not intended to limit the present invention. Singular forms as used herein also include plural forms unless the phrases clearly indicate the opposite.

The meaning of "comprising" as used in the specification specifies a specific characteristic, region, integer, step, action, element and/or component, and other specific characteristic, region, integer, step, action, element, component and/or group It does not exclude the existence or addition of

Although not defined differently, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms defined in a commonly used dictionary are additionally interpreted as having a meaning consistent with the related technical literature and the presently disclosed content, and are not interpreted in an ideal or very formal meaning unless defined.

In general, a metal plating layer formed by a physical vapor deposition (PVD) method in a vacuum is formed under a tremendous rapid cooling condition due to condensation from a gas phase to a solid phase. Accordingly, there is a characteristic that sufficient growth of the crystal is not possible, and thus a very fine grain size is obtained. Various materials can be improved according to such grain refinement, and it is typically expected to improve strength (strengthening grain refinement) according to grain refinement.

However, due to the increase in strength and brittleness due to excessive grain refinement of the plated steel sheet plated by the vacuum deposition method, problems related to workability such as cracking of the plated layer and peeling of the plated layer may occur in various processing processes performed in the post process.

The present inventors have studied in depth to solve the above-described problems with the plated steel sheet manufactured by the vacuum deposition method, and when micro-voids are formed in the plated layer during the vacuum deposition process, such micropores are generated during processing. It was found that the processability can be improved by absorbing the stress and blocking the propagation of cracks, and the present invention was completed.

Hereinafter, a zinc-based plated steel sheet having excellent workability according to an aspect of the present invention will be described in detail. In the present invention, when expressing the content of each element, it is necessary to note that, unless otherwise specified, it means weight %. In addition, the ratio of crystals or tissues is based on the area unless otherwise indicated.

First, a zinc-based plated steel sheet according to an aspect of the present invention includes a holding steel sheet and a zinc-based plating layer vacuum-deposited on the holding steel sheet.

In the present invention, the type of the holding steel sheet may not be particularly limited. However, as a non-limiting example, the holding steel sheet may be a high-strength steel sheet, and it is more preferable that it is a UHSS (Ultra High Strength Steel) steel sheet having a yield strength of 1.2 Gpa or more.

In addition, the alloy composition of the holding steel sheet in the present invention may not be particularly limited. However, as a non-limiting example, the holding steel sheet may contain, in weight%, C: 0.2 to 0.25%, Si: 0.5 to 1.0%, Mn: 0.8 to 1.6%, the balance Fe and unavoidable impurities.

A zinc-based plating layer formed by vacuum deposition may be provided on the holding steel sheet. The zinc-based plating layer may be a pure zinc plating layer containing only pure Zn and other unavoidable impurities, or a zinc alloy plating layer containing at least one of Zn and Mg, Al, and Ni.

In addition, in some cases, it may be a combination of one or more pure zinc plating layers and one or more zinc alloy plating layers, or a multilayer structure consisting of a combination of one or more zinc alloy plating layers deposited by different sources.

When the zinc-based plating layer is a zinc alloy plating layer, the component range of Zn, Mg, Al, and Ni may not be particularly limited, but as a non-limiting embodiment, the zinc alloy plating layer is, in weight%, Mg: 0.1 to 20%, Al: 0.1-10%, Ni: 0.1-5%, balance Zn and other unavoidable impurities.

The zinc-based plating layer may include micropores having a size of several to several hundred nm therein, and the porosity of the zinc-based plating layer may be 4.3% or more based on a cross-sectional area. Here, the porosity may be defined as a ratio of the area occupied by micropores to the total area of the plating layer when the cross section of the zinc-based plating layer is observed. In the present invention, the porosity can be measured through an electron microscope and image analyzer after taking and polishing an arbitrary cross section of the zinc-based plating layer, or observing the cross-section of the zinc-based plating layer using a focused ion beam (FIB). It may be measured by, but is not limited thereto.

The micropores present in the zinc-based plating layer may be mainly located in an interface-side region between the base steel sheet and the zinc-based plating layer or a surface-side region of the zinc-based plating layer within the zinc-based plating layer. When the zinc-based plating layer has a multilayer structure, the micropores are in the interface side region between the holding steel sheet and the zinc-based plating layer, the interface between each plating layer constituting the zinc-based plating layer, and the outermost surface side of the zinc-based plating layer. Can be formed. However, this does not mean that micropores should be formed only at the interface or surface portion of the plating layer, and some micropores may be formed inside the plating layer.

In the present invention, since metal vapor is sprayed at an angle of incidence that is not perpendicular to the surface of the holding steel sheet during vacuum deposition, the zinc-based plating layer is also grown with an inclination according to the incident angle of the metal vapor. Due to the angle of incidence with an inclination, it is not a dense structure in a direction perpendicular to the initial (e.g., interface) and late (e.g., surface) deposition, but is formed into a structure that grows in an oblique direction and has a number of micropores. .

Since most of these micropores are very small with a size of several to several hundred nm, they can absorb stress generated during processing and buffer against deformation without deteriorating physical properties of the plating layer such as corrosion resistance. In particular, it can block the propagation of cracks to prevent the occurrence of cracks and peeling of the plating layer during processing.

The size of the micropores may not be particularly limited, but may have a size of 50 to 500 nm as a non-limiting embodiment.

The porosity of the zinc-based plating layer may be 4.3% or more based on the cross-sectional area. As described above, when a zinc-based plating layer is formed by physical vapor deposition, a space in which metal atoms are unintentionally empty, that is, a small amount of micropores, due to insufficient movement and diffusion time of metal atoms as it is performed under rapid cooling conditions. void) may occur. In the prior art, the porosity due to the micropores is somewhat different depending on the deposition conditions, but is mostly formed to 3 to 4% or less, and is generally neglected or recognized as a defect in the plating layer because it does not significantly affect the physical properties of the plating layer. there was. However, the present invention is based on the technical idea that such micropores can improve workability by absorbing stress generated during processing and blocking the propagation of cracks, and for this purpose, the porosity of the zinc-based plating layer is more than the conventional one. It can be limited to the high level of 4.3% or higher.

As can be seen from the results of the example shown in FIG. 5, if the porosity of the zinc-based plating layer is 4.3% or more, the intended effect can be obtained, and thus the upper limit of the porosity may not be separately limited. However, if the spraying distance is set very close to less than 2cm, the upper limit of the porosity may be determined in consideration of the porosity obtained when the spraying distance is 2cm, as there is a possibility that the equipment may be damaged if the steel sheet is shaken due to the occurrence of an unexpected situation or when the welding part is sold. It can be limited to 18.0% or less.

Hereinafter, a method of manufacturing a zinc-based plated steel sheet having excellent workability, which is another aspect of the present invention, will be described in detail. However, the manufacturing method described below is only one of all possible embodiments, and does not mean that the galvanized steel sheet of the present invention must be manufactured only by the following manufacturing method.

The zinc-based plated steel sheet according to the present invention comprises the steps of preparing a holding steel sheet; Including, in the step of vacuum deposition by spraying metal vapor of zinc or zinc alloy on at least one surface of the holding steel sheet through a nozzle, at least a portion of the metal vapor is at least one surface of the holding steel sheet It can be manufactured through a manufacturing method that is sprayed so as to have an incidence angle that is not perpendicular to.

First, prepare your own steel plate. As described above, the holding steel sheet is not particularly limited. As a preferred embodiment, the holding steel sheet may be from high strength steel to advanced high strength steel (AHSS) and ultra high strength steel of UHSS class, but is not limited thereto.

Metal vapor of zinc or zinc alloy is sprayed onto at least one surface of the holding steel sheet through a nozzle for vacuum deposition, but at least a portion of the metal vapor is sprayed so as to have an incidence angle that is not perpendicular to the surface of the holding steel sheet. I can.

Fig. 1 shows an injection form in a general nozzle. As shown in Fig. 1, since the spray type in a general nozzle has a constant spray angle, it is common to perform uniform plating by sufficiently setting a distance (spray distance) between the nozzle and the object to be plated. .

In fact, in zinc-magnesium alloy plating using PVD vacuum deposition methods such as conventional EML-PVD, as shown in FIG. 2, plating is usually performed with a spray distance of about 14 cm, and the resulting Zn-Mg alloy thin film The cross section of is dense and uniform as shown in FIG. 3 (a). However, in the case of such a dense Zn-Mg alloy thin film as described above, the adhesion of the plating layer decreases during processing as shown in FIG. 3 (b) due to high brittleness, and as shown in FIG. 3 (c), cracks and There was a problem that peeling occurred. Here, in FIG. 3(c), the bright part is the plating layer, and the dark part shows the part where the base iron is exposed due to cracking and peeling.

However, when the spraying distance is reduced, at least some of the metal vapor is sprayed with an incident angle that is not perpendicular to the surface of the plated material, that is, the holding steel sheet due to the radiation angle, which is a characteristic of the nozzle. In this case, the formed plating layer is also grown with an inclination according to the angle of incidence of the metal vapor, and as a result, a plating layer structure having a plurality of micropores that is not relatively dense compared to the conventional plating layer is formed.

In the case of vacuum deposition, if the angle of incidence of the metal vapor to the steel sheet is not a vertical angle, the object of the present invention may be achieved, and thus may not be particularly limited. As a preferred embodiment, it may be greater than 30° and less than 90°, and may be greater than 90° and less than 150°, but is not limited thereto.

Accordingly, in the method of manufacturing a galvanized steel sheet according to another aspect of the present invention, in order to ensure that at least some of the metal vapor is sprayed at an angle of incidence other than perpendicular to at least one surface of the holding steel sheet, the vacuum deposition is performed based on the EML-PVD method. The spraying distance of can be limited to 6cm or less. As shown in Fig. 5, the spraying distance during vacuum deposition is inversely correlated with the porosity of the plating layer of the plated steel sheet to be manufactured, and when the spraying distance is 6cm or less, a porosity of 4.3% or more can be secured, thereby securing excellent workability. I can. However, the spray distance may be different depending on the vacuum deposition method, and the spray distance according to the vacuum deposition method other than the EML-PVD method can be experimentally obtained under conditions of securing a porosity of 4.3% or more.

On the other hand, the smaller the spraying distance is, the higher the porosity ratio is, so the lower limit of the spraying distance may not be separately limited.However, if the spraying distance is too small, there is a possibility of equipment damage when the steel plate shakes due to the occurrence of an unexpected situation or when the welding part is sold. As can occur, the lower limit can be limited to 2cm or more.

Micropores inside the zinc-based plating layer can be formed by changing the shape of the nozzle. In this case, as a preferred embodiment, the nozzle may be a diffusion type nozzle having the same diameter at the entrance and exit sides or a larger diameter at the exit side based on the cross section of the nozzle.

Fig. 9 shows a jet type according to a nozzle shape. In the case of a generally used straight nozzle, it is manufactured in the form as shown in FIG. 9 (a). In the case of using a straight nozzle, a spraying distance of about 6 cm or less is required in order to form an angle at which metal vapor is incident on the steel plate that is to be plated during the deposition process. However, if the spraying distance is too small, there is a possibility of equipment damage when the steel plate shakes due to the occurrence of an unexpected situation or when the welding part is sold.

However, when the spray angle is increased by using a diffusion type nozzle having the same diameter on the inlet and outlet based on the nozzle cross-section as shown in Fig. 9(b) or the diameter on the outlet side is large, the distance between the nozzle and the steel plate is increased to about 10 cm. Also, the desired porosity of the plating layer can be obtained, and the effect of preventing cracking and peeling of the processed portion can be obtained even in the thus formed plating layer. Therefore, in the case of using a diffusion type nozzle, the spraying distance can be limited to 10 cm or less.

Hereinafter, the present invention will be described in more detail through examples. However, it should be noted that the following examples are only for exemplifying the present invention and not for limiting the scope of the present invention. This is because the scope of the present invention is determined by matters described in the claims and matters reasonably inferred therefrom.

(Example 1)

First, a base steel sheet having an alloy composition containing 0.22C-0.7Si-1.0Mn in weight% was prepared, and the spraying distance was changed to 2~16cm on the base steel sheet according to the conditions in Table 1 below. A Zn-Mg alloy plated layer containing 10% Mg and the balance Zn was formed. At this time, the Zn-Mg alloy plating layer was formed to a thickness of 2 μm in order to remove an error according to the thickness.

Thereafter, for each Zn-Mg plated steel sheet, the porosity and plating adhesion of the Zn-Mg alloy plated layer were evaluated, and the results are shown together in Table 1 below.

The porosity of the Zn-Mg alloy plated layer was determined by cutting the Zn-Mg plated steel sheet and observing the cross section with a scanning electron microscope (SEM), and measuring the porosity of the Zn-Mg alloy plated layer through an image analyzer. At this time, for each example, a cross section was taken at three arbitrary points, the porosity was measured, and the average value was taken as the porosity of the example.

The processing adhesion was tested by taping the outer winding portion after the 0T bending test, and the width of the stripped area buried on the tape was measured.

Example No. Nozzle shape Spray distance (TS, ㎝) Porosity (%) Peeling width (mm) 1-1 Straight 2 17.4 0 1-2 Straight 4 8.7 0 1-3 Straight 6 4.3 0 1-4 Straight 8 1.8 0.9 1-5 Straight 10 0.7 1.8 1-6 Straight 12 0 1.9 1-7 Straight 14 0 2.7 1-8 Straight 16 0 2.6 1-9 Diffuse 8 9.2 0 1-10 Diffuse 10 4.5 0 1-11 Diffuse 12 2.7 0.5

4 shows a cross-sectional transmission electron microscope (TEM) photograph of the Zn-Mg alloy plating layer of each of the plated steel sheets of Examples 1-1 to 1-8, and micropores appearing in white on the photograph as the spray distance decreases. It is easy to see the increase.

More specifically, referring to FIG. 4, there was no significant change in the plating layer until the spraying distance of 12 to 16 cm, which is the same level as in the prior art, Micropores (white part) began to appear, and at a spray distance of 2 cm, the porosity was measured to be about 17.4%, confirming that the porosity increased as the spray distance decreased.

5 is a graph showing the porosity according to the spray distance and the 0T bending test result together, and FIG. 6 is a tape taken after the 0T bending test for Examples 1-1 to 1-8. It shows a picture. As can be seen in FIGS. 5 and 6, in the case of Zn-Mg plated steel sheet manufactured at a spray distance of 14 cm (that is, in the case of Example 1-7), peeling of the processed part occurred, but the spray distance decreased. Accordingly, the peeling width gradually decreased, and it can be seen that peeling did not occur in Example 1-3 in which the spraying distance of 6 cm or less was applied.

(Example 2)

The present inventors produced a Zn-Mg plated steel sheet by increasing the thickness of the plating layer to about 4 μm at a spray distance of 2 cm, and then performed a 0T bending test in the same manner as in the above example. In the case of Example 2, the porosity was measured to be 0% and the peeling width was measured to be 2.9 mm.

7 is a photograph showing a TEM cross-section of a Zn-Mg alloy plated steel sheet manufactured at a spray distance of 2 cm. Even if the thickness of the plating layer was changed through the coating speed, it was confirmed that micropores were formed at the interface and the surface of the plating layer (refer to the arrow), and it was also confirmed that the adhesion was improved.

(Example 3)

In the case of Example 3, unlike Example 1, pure zinc plating having relatively excellent ductility compared to zinc alloy was performed, and other conditions were applied in the same manner as in Example 1. After measuring the porosity in the same manner as in Example 1 and performing the 0T bending test, it was observed whether the plating layer cracked, and the results are shown in Table 2 below.

Example No. Nozzle shape Spray distance (TS, ㎝) Porosity (%) Whether the plating layer is cracked 3-1 Straight 14 0 O 3-2 Straight 6 4.6 X

8 shows a comparison of the occurrence of cracks/peeling in the processed part according to the presence or absence of pore formation in the galvanized steel sheet. As a result of checking whether cracks and peeling in the processed part of the galvanized steel sheet according to the presence or absence of micropore formation, in the case of the galvanized steel sheet without pore formation, a number of cracks and peeling occurred on the surface of the processed part, In the case of the galvanized steel sheet having pores, it was confirmed that cracks and peeling did not occur on the surface of the processed part as shown in FIG. 8 (c). Therefore, it was confirmed that the occurrence of cracks in the processed part was remarkably reduced when the porosity was formed by more than 4.3% in the galvanized steel sheet as in the zinc alloy steel sheet.

Although it has been described with reference to the above embodiments, it will be understood that a person skilled in the art can variously modify and change the present invention within the scope not departing from the spirit and scope of the present invention described in the following claims. I will be able to.

Claims (13)

Holding steel plate; And
Including; a zinc-based plating layer provided on the holding steel sheet,
The zinc-based plating layer contains micropores therein,
A galvanized steel sheet having a porosity of the zinc-based plating layer of 4.3% or more based on a cross-sectional area.
The method of claim 1,
The micropores are inside the galvanized layer,
A galvanized steel sheet, characterized in that it is located in at least one of an interface-side region between the holding steel sheet and the zinc-based plating layer and an outermost surface-side region of the zinc-based plating layer.
The method of claim 1,
The zinc-based plating layer is a zinc-based plated steel sheet, characterized in that the zinc-plated layer.
The method of claim 1,
The zinc-based plated layer is a zinc-based plated steel sheet, characterized in that it is a zinc alloy plated layer containing at least one of Zn, and Mg, Al, and Ni.
The method of claim 1,
The zinc-based plated layer is a zinc-based plated steel sheet, characterized in that the multi-layered structure consisting of a combination of two or more selected from a zinc plated layer and a zinc alloy plated layer containing at least one of Zn, and Mg, Al, and Ni.
The method of claim 5,
The micropores are inside the galvanized layer,
Galvanized steel sheet, characterized in that located in at least one of an interface side region between the holding steel sheet and the zinc-based plating layer, an interface between the plating layer, and an outermost surface side region of the zinc-based plating layer.
The method of claim 1,
Galvanized steel sheet, characterized in that the size of the micropores is 50 ~ 500nm.
The method of claim 1,
The porosity is a zinc-based plated steel sheet, characterized in that not less than 4.3% and not more than 18.0%.
As a method of manufacturing a zinc-based plated steel sheet using a vacuum deposition method,
Preparing a holding steel plate;
Including; and vacuum deposition by spraying metal vapor of zinc or zinc alloy onto at least one surface of the holding steel sheet through a nozzle,
In the vacuum deposition step, at least a portion of the metal vapor is sprayed so as to have an incidence angle that is not perpendicular to at least one surface of the holding steel sheet.
The method of claim 9,
The vacuum deposition method is an Electromagnetic Levitation Physical Vapor Deposition (EML-PVD) method,
A method of manufacturing a galvanized steel sheet, characterized in that the distance between the nozzle and the holding steel sheet is 6 cm or less (excluding 0 cm).
The method of claim 10,
A method of manufacturing a galvanized steel sheet, characterized in that the distance between the nozzle and the holding steel sheet is 2 to 6 cm.
The method of claim 9,
The nozzle is a method of manufacturing a galvanized steel sheet, characterized in that the nozzle is a diffusion type nozzle having the same diameter at the entrance and exit sides or a larger diameter at the exit side based on the nozzle cross section.
The method of claim 12,
A method of manufacturing a galvanized steel sheet, characterized in that the distance between the nozzle and the holding steel sheet is 10 cm or less (excluding 0 cm).

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