KR102310202B1 - Plated mas steel sheet having a patterned surface and a method for preparing it - Google Patents

Abstract

The present invention relates to a patterned black Al-Mg-based plated steel sheet comprising a steel sheet and an Al-Mg-Si alloy layer positioned on the steel sheet. The Al-Mg-Si alloy layer exists in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase. The Mg-Si alloy particles form a blackening inhibiting layer to form a non-blackening portion on the surface of the plated steel sheet during the blackening process. In addition, the present invention heat-treats an Al-Mg-Si alloy layer present in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase on the surface of the steel sheet to at least partially form a _{Mg 2 Si layer on the surface of the steel sheet.} step; and applying water vapor at a high temperature to the steel sheet in an airtight container to prepare a black plated steel sheet in which blackened and non-blackened portions are mixed, preferably patterned, Al-Mg having a black plating layer It relates to a method for manufacturing a plated steel sheet.

Description

Surface patterned Al-Mg-based (MAS) coated steel sheet and manufacturing method thereof

The present invention relates to a method for manufacturing a surface pattern of an Al-Mg-based (MAS) plated steel sheet by applying a MAS steel sheet to blackening technology. In the present invention, a specific alloy structure that does not blacken is created and a high-grade pattern pattern is produced on the surface of the steel sheet through this.

In the fields of building materials, automobiles, home appliances, and the like, plated steel sheets with advanced black appearance have been continuously developed. As a method of blackening the surface of a steel sheet, there is a method of forming a black coating layer by applying a black paint to the surface of the steel sheet, but this has problems such as cost due to the additional process of forming the coating layer, and insufficient corrosion resistance and weather resistance of the coating layer. not desirable from the point of view. Therefore, in recent years, a method of manufacturing a black plated steel sheet by applying a plating layer containing at least one of molten Zn, Al, or Mg on the steel sheet surface and blackening it has been predominantly used.

A method of forming a thin black film on the surface layer of a steel sheet by spraying high-temperature steam for 24 hours or more on an Al-Mg-Zn plated steel sheet is known. In addition, a technique for manufacturing a black plated steel sheet at a high speed using a PosMAC material under a high oxygen concentration is known. In particular, a technique for blackening the plating layer of MAS steel sheet by spraying hot steam is known. However, the prior art only discloses a technique for forming a single black layer having a uniform non-pattern.

The present inventors found that when an Al-Mg-Si-based plated steel sheet (MAS steel sheet) is steam treated at a high temperature in a sealed reactor, the specific part with the blackening inhibiting layer is not blackened, and the part without the blackening inhibiting layer is blackened, It has been discovered that a surface pattern can be created and the present invention has been completed. Therefore, the present invention relates to a technique for manufacturing a high-grade pattern in which a blackening part and a non-blackening part are mixed on the surface of a plated steel sheet using a specific alloy structure that does not blacken, in addition to the blackening technique using the MAS steel sheet.

The present invention relates to a patterned black Al-Mg-based plated steel sheet comprising a steel sheet and an Al-Mg-Si alloy layer positioned on the steel sheet. The Al-Mg-Si alloy layer exists in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase. The Mg-Si alloy particles form a blackening inhibiting layer to form a non-blackening portion on the surface of the plated steel sheet during the blackening process. The plated steel sheet includes 8 to 10% by weight of Si, 88 to 90% by weight of Al and the balance Fe based on the total weight of the plated steel sheet, and the Al-Mg-Si alloy layer is Mg based on the total weight of the alloy layer. 15 to 90% by weight.

In addition, the present invention heat-treats an Al-Mg-Si alloy layer present in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase on the surface of the steel sheet to at least partially form a _{Mg 2 Si layer on the surface of the steel sheet.} step; and applying water vapor at a high temperature to the steel sheet in an airtight container to prepare a black plated steel sheet in which blackened and non-blackened portions are mixed, preferably patterned, Al-Mg having a black plating layer It relates to a method for manufacturing a plated steel sheet. In the blackening step, if the partially formed Mg ₂ Si layer acts as a blackening inhibiting layer and a non-black portion is formed in the blackening process, the overall black portion and the non-black portion are mixed, repeated, or preferably alternating patterning Black plating is formed on the surface of the steel sheet.

According to the present invention, the blackened portion and the non-blackened portion in the plating layer are mixed and/or repeated, or alternately appearing, thereby providing a plated steel sheet with a beautiful, high-quality texture.

1 shows the degree of blackening after the blackening process (150° C. 95% relative humidity, 1 hour) according to the thickness of Mg vacuum plating and heat treatment time.
2 shows the TEM-EDS result of the gray part after the blackening process.
3 shows the TEM-EDS results of the black part after the blackening process.
4 shows the results after the blackening process of the comparative example.

Unless otherwise defined, all terms (including technical and scientific terms) used in this specification may be used with meanings commonly understood by those of ordinary skill in the art to which the present invention belongs. When a part "includes" a certain component throughout the specification, this means that other components may be further included, rather than excluding other components, unless otherwise stated. The singular also includes the plural, unless the phrase specifically states otherwise.

In addition, since the size and thickness of each component shown in the drawings are arbitrarily indicated for convenience of description, the present invention is not necessarily limited to the illustrated bar.

Throughout the specification, when a part, such as a layer, film, region, plate, etc., is referred to as being “on” or “on” another part, it means not only when it is “immediately on” another part, but also another part in between. Including cases where there are parts.

Throughout the specification, when a part, such as a layer, film, region, plate, etc., is said to be “on” or “on” another part, it means that it is located above or below the target part, and must be It does not mean that it is located on the upper side with respect to the direction of gravity.

Throughout the specification, unless otherwise defined, "layer A" includes not only the case in which the corresponding layer consists only of A, but also the case in which the layer includes A.

Throughout the specification, unless otherwise defined, the term "A-B alloy layer" includes not only the case in which the corresponding layer consists only of the A-B alloy, but also the case in which the layer includes the A-B alloy. Further, throughout the specification, unless otherwise defined, "ABC alloy layer" refers to an AB alloy and an AC alloy, or an AB alloy and a BC alloy, or BC, as well as when the layer includes all of A, B, and C. Also includes alloys and AC alloys.

MAS steel sheet is a plated steel sheet with strong corrosion resistance developed by POSCO. It is manufactured by coating and heat-treating a material containing aluminum, magnesium, and silicon on the surface of the steel sheet. It is a plated steel plate.

MAS steel sheet is a plated steel sheet having an alloy layer containing Al, Si, and/or Mg on the steel sheet. The MAS-coated steel sheet of the present invention preferably includes an Al-Mg-Si alloy layer, an Al-Mg alloy layer, and an Mg-Si alloy layer, and may optionally include an Al-Si alloy layer. Preferably, the Al-Mg-Si alloy layer is present in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase. The Mg-Si alloy particles may form an Mg ₂ Si blackening inhibiting layer.

The plated steel sheet of the present invention contains Si in an amount of 8 to 10% by weight based on the total weight of the plated steel sheet, 88 to 90% by weight of Al, and Fe as the balance. In the plated steel sheet, the Al-Mg-Si alloy layer contains 15 to 90% by weight of Mg based on the total weight of the alloy layer. In addition, the Al-Mg-Si alloy layer may include an Al-Mg alloy and an Mg-Si alloy in an amount of 1 to 70 wt%, respectively, based on the total weight of the alloy layer.

The present invention heat-treats an Al-Mg alloy and an Mg-Si alloy that are present in a form in which Mg-Si alloy particles are included in the Al-Mg alloy phase on the surface of the steel sheet to at least partially form a _{Mg 2 Si layer on the surface of the steel sheet} step; and blackening the plated steel sheet by applying water vapor at a high temperature to the steel sheet in an airtight container, wherein the partially formed Mg ₂ Si layer acts as a blackening inhibiting layer, so that a black portion and a non-black portion are mixed. It relates to a method for manufacturing an Al-Mg-based plated steel sheet having a black plating layer having a pattern or pattern in which black portions and non-black portions are mixed, comprising the step of being formed on the surface of the steel sheet. In the blackening step, when the partially formed Mg ₂ Si layer acts as a blackening inhibiting layer and a non-black portion is formed in the blackening process, a patterned black plating in which the black portion and the non-black portion alternate as a whole is formed on the surface of the steel sheet do.

The heat treatment step is preferably performed at a temperature higher than the conventional blackening heat treatment temperature. The heat treatment temperature is 300 to 400°C, preferably 320 to 375°C. The heat treatment time is 1 minute to 30 minutes, preferably 3 minutes to 20 minutes, and more preferably 5 minutes to 15 minutes. _{By the heat treatment step, the Mg 2} Si layer is at least partially formed in the alloy layer on the surface of the steel sheet.

In the blackening step of the plated steel sheet, as the blackening proceeds, the non-blackened portion and the blackened portion are more reliably contrasted to form a stronger pattern. Accordingly, it can be understood that the degree of blackening and the degree of patterning are mutually proportional.

The degree of blackening may be determined according to the thickness of the Mg plating, and the temperature and time of the heat treatment step. The thickness, heat treatment temperature and time of Mg plating may be proportional to the degree of blackening. Therefore, the degree of blackening and patterning of the plated steel sheet can be variously changed by controlling the heat treatment temperature and time.

The blackening step is performed by applying high-temperature steam to the heat-treated plated steel sheet in a sealed container. The at least partially formed Mg ₂ Si layer acts as a blackening inhibiting layer in the blackening step. The Mg ₂ Si layer forms a non-blackened portion in the blackening step, whereby a patterned black plating in which the black portion and the non-black portion intersect is formed on the surface of the plated steel sheet. The _{more particles of Mg 2} Si, the more the blackening is inhibited. _{Therefore, since the content of the Mg 2} Si particles formed in the alloy layer is non-uniform, the shape of the generated black pattern may not be uniform.

The temperature of the blackening step is 105°C to 200°C, preferably 140°C to 160°C. Humidity in the blackening step is 50% to 100%, and the higher the humidity, the more preferable. The time of the blackening step is 5 minutes to 2 hours, preferably 30 minutes to 1 hour. In the blackening step, blackening-non-blackening proceeds according to the presence of the Mg alloy layer to achieve patterning, and in particular, depending on the temperature, humidity, and time change of the blackening step, color control between gray color and black color is possible. In one embodiment, the humidity is 95% and the time is 1 hour in the blackening process.

The degree of blackening may be determined according to changes in temperature, humidity, and time of the blackening step. The blackening temperature and time may be proportional to the blackening degree. Therefore, by controlling the blackening temperature and time, the degree of blackening of the plated steel sheet can be changed from light gray to completely black.

Hereinafter, embodiments of the present invention will be described in detail. However, this is provided as an example, and the present invention is not limited thereto, and the present invention is only defined by the scope of the claims to be described later.

Example

Example 1 to 9

9 steel sheets including 9 wt% Si, 88 wt% Al, and an Al plating layer containing Fe as the balance were prepared on the cold-rolled steel sheet. While supplying the steel sheets into the vacuum vessel through the supply device, Mg was coated on the Al plating layer through an electromagnetic levitation source installed in the vacuum vessel so that the thickness of Mg vacuum plating was 1.0 μm, 1.5 μm, and 2.0 μm per 3 pieces. After the coating was completed, the steel sheets were continuously moved and discharged to the atmosphere, and then each steel sheet was heat-treated at 400° C. for 2 minutes, 3 minutes, and 4 minutes in the atmosphere using an induction heating device. After the heat treatment was completed, the steel sheet was continuously transferred to obtain a manufactured alloy coated steel sheet. After these steel sheets were fed back into the vacuum vessel, steam was added at 150°C under 95% relative humidity. As shown in Fig. 1, a patterned blackened plated steel sheet in which various blackening-non-blackening portions were non-uniformly formed was obtained. The table below shows the degree of blackening and patterning according to each Example as relative strength.

Example number Mg vacuum plating thickness (㎛) Heat treatment temperature (℃) Heat treatment time (min) degree of blackening degree of patterning One One 400 2 approximately approximately 2 One 400 3 approximately middle 3 One 400 4 approximately River 4 1.5 400 2 middle approximately 5 1.5 400 3 middle middle 6 1.5 400 4 middle River 7 2 400 2 River approximately 8 2 400 3 River middle 9 2 400 4 River River

As shown in the above examples, the overall blackening degree of the plated steel sheet was proportional to the thickness of the Mg vacuum plating. However, in the plated steel sheet having each Mg vacuum plating thickness, the pattern strength of the non-blackened portion and the blackened portion was found to be proportional to the heat treatment time. The blackened portion and the non-blackened portion were observed by TEM-EDS. The results are shown in Figures 2 and 3. 2 shows the TEM-EDS results of the gray part (non-blackening part) after the blackening process. As the Mg ₂ Si layer increases, the blackening is inhibited, and it can be seen that the gray part is formed. 3 shows the TEM-EDS result of the black part after the blackening process, it was found that the more Mg, the stronger the blackening.

comparative example

MAS steel sheet was manufactured in the same process as in Examples 1 to 9, but the heat treatment step after vacuum plating of Mg PVD was performed at 250° C. for 60 minutes. After heat treatment, as a blackening process, the degree of blackening of the surface of the plated steel sheet was examined after treatment at 150° C., 95% RH, and 1 hour. As shown in FIG. 4 , there was no non-blackening part on the surface, and a uniform black appearance was confirmed without a pattern.

Claims (10)

grater; and
Al-Mg-Si alloy layer positioned on the steel plate
As an Al-Mg-based plated steel sheet having a surface in which a black portion and a non-black portion are mixed, comprising:
To form a black portion, wherein the Al-Mg-Si alloy layer comprises a Mg ₂ Si alloy layer in the layer at least in part, to the Mg ₂ Si layer acts as a blackening layer is not inhibited
Al-Mg-based plated steel sheet. The plated steel sheet according to claim 1, wherein the plated steel sheet comprises 8 to 10% by weight of Si, 88 to 90% by weight of Al, and the balance Fe based on the total weight of the plated steel sheet. The plated steel sheet according to claim 1, wherein the Al-Mg-Si alloy layer comprises 15 to 90 wt% of Mg based on the total weight of the alloy layer. A step of applying and heat-treating Al-Mg alloy and Mg-Si alloy on the surface of the steel sheet so that Mg-Si alloy particles are included in the Al-Mg alloy phase, and Mg ₂ Si on the surface of the steel sheet by the heat treatment at least partially forming a layer;
A step of blackening the plated steel sheet by applying water vapor to the steel sheet at a high temperature in a closed container, wherein the partially formed Mg ₂ Si layer acts as a blackening inhibiting layer, so that a black portion and a non-black portion are mixed. Formed on the steel plate surface
A method of manufacturing an Al-Mg-based plated steel sheet having a surface in which black portions and non-black portions are mixed, comprising: The method according to claim 4, wherein the heat treatment temperature of the heat treatment step is 300 to 400° C., and the heat treatment time is 1 minute to 30 minutes. The method according to claim 4, wherein the heat treatment temperature of the heat treatment step is 320 to 375° C., and the heat treatment time is 4 minutes to 20 minutes. The method according to claim 4, wherein the blackening temperature is 105°C to 200°C, or 140°C to 160°C, the blackening humidity is 50% to 100%, and the blackening time is 30 minutes to 1 hour. The method according to claim 4, wherein _{blackening is inhibited in proportion to the content of Mg 2} Si, thereby forming a non-blackening surface on the plating layer. An Al-Mg-based plated steel sheet having a surface in which black portions and non-black portions are mixed, manufactured according to any one of claims 4 to 8. A step of applying and heat-treating Al-Mg alloy and Mg-Si alloy on the surface of the steel sheet so that Mg-Si alloy particles are included in the Al-Mg alloy phase, and Mg ₂ Si on the surface of the steel sheet by the heat treatment at least partially forming a layer; and
A step of blackening the plated steel sheet by applying water vapor to the steel sheet at a high temperature in a closed container, wherein the partially formed Mg ₂ Si layer acts as a blackening inhibiting layer, so that a black portion and a non-black portion are mixed. Formed on the steel plate surface
A method of forming a pattern in which a black portion and a non-black portion are mixed on the surface of an Al-Mg-based plated steel sheet, comprising a.

Images