Plated steel sheet

Abstract

The plated steel sheet has a steel sheet and a plating layer disposed on the surface of the above-mentioned steel sheet. The chemical composition of the above-mentioned plating layer contains Al: 10.0 to 25.0%, Mg: 3.0 to 10.0%, Fe: 0.01 to 2.00%, Si: more than 0.00% and 2.00% or less, and the balance contains Zn and impurities. When performing grazing incidence X-ray diffraction measurement on the above-mentioned plating layer under the conditions of using Cu-Kα rays, setting the acceleration voltage as the X-ray output to 50 kV, and setting the X-ray incident angle with respect to the surface of the above-mentioned plating layer to 1°, Mg 21 Zn 25 The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) of the (300) plane of the phase and the (002) plane of the η-Zn phase exceeds 0.3.

Description

Technical Field

[0001] The present invention relates to a plated steel sheet.

[0002] This application claims priority based on Japanese Patent Application No. 2022-130521 filed on August 18, 2022, and incorporates its content herein. Background Art

[0003] A Zn-Al-Mg hot-dip plated steel sheet having a hot-dip Zn layer containing Al and Mg has excellent corrosion resistance. Therefore, for example, as a material for structural members such as building materials that require corrosion resistance, Zn-Al-Mg hot-dip plated steel sheets are widely used.

[0004] For example, Patent Document 1 describes a plated steel material having a steel material and a plating layer containing a Zn-Al-Mg alloy layer disposed on the surface of the steel material. The Zn-Al-Mg alloy layer has a Zn phase and contains a Mg-Sn intermetallic compound phase in the Zn phase. The plating layer has the following chemical composition: containing, by mass%, Zn: more than 65.0%, Al: more than 5.0% and less than 25.0%, Mg: more than 3.0% and less than 12.5%, Sn: 0.1% to 20.0%, and impurities, and satisfying the following Formulas 1 to 5.

[0005] Formula 1: Bi + In < Sn

[0006] Formula 2: Y + La + Ce ≤ Ca

[0007] Formula 3: Si < Sn

[0008] Formula 4: O ≤ Cr + Ti + Ni + Co + V + Nb + Cu + Mn < 0.25

[0009] Formula 5: O ≤ Sr + Sb + Pb + B < 0.5

[0010] Patent Document 2 describes a plated steel material having a steel material and a plating layer disposed on the surface of the steel material and containing a Zn-Al-Mg alloy layer. Among them, in the cross section of the Zn-Al-Mg alloy layer, the area fraction of the MgZn2 phase is 45 to 75%, the total area fraction of the MgZn2 phase and the Al phase is 70% or more, and the area fraction of the Zn-Al-MgZn2 ternary eutectic structure is 0 to 5%. The plating layer has the following chemical composition: containing Zn: more than 44.90% and less than 79.90%, Al: more than 15% and less than 35%, Mg: more than 5% and less than 20%, Ca: 0.1% or more and less than 3.0%, and impurities by mass%. When the element group A is set as Y, La, and Ce, the element group B is set as Cr, Ti, Ni, Co, V, Nb, Cu, and Mn, the element group C is set as Sr, Sb, and Pb, and the element group D is set as Sn, Bi, and In, the total content of the elements selected from the element group A is 0% to 0.5%, the total content of Ca and the elements selected from the element group A is 0.1% or more and less than 3.0%, the total content of the elements selected from the element group B is 0% to 0.25%, the total content of the elements selected from the element group C is 0% to 0.5%, and the total content of the elements selected from the element group D is 0% to 20.00%.

[0011] Patent Document 3 describes a hot-dip Al-Zn-Mg-Si steel sheet having a plating film on the surface of the steel sheet. Among them, the plating film includes an interface alloy layer present at the interface with the base steel sheet and a main layer present on the alloy layer, contains 25 to 80% by mass of Al, more than 0.6% by mass and 15% by mass or less of Si, and more than 0.1% by mass and 25% by mass or less of Mg, and the area ratio of Mg2Si at the surface of the main layer is 10% or more.

[0012] In recent years, for hot-dip plated steel materials used in building materials such as roofs and wall materials, excellent corrosion resistance of the plating layer itself, i.e., planar corrosion resistance, and corrosion resistance of the cut end face, i.e., end face corrosion resistance, are required. On the other hand, technologies that balance both planar corrosion resistance and end face corrosion resistance at a high level have not been studied.

[0013] Prior Art Documents

[0014] Patent Documents

[0015] Patent Document 1: International Publication No. 2018 / 139619

[0016] Patent Document 2: International Publication No. 2018 / 139620

[0017] Patent Document 3: Japanese Patent Application Laid-Open No. 2016-166414 Summary of the Invention

[0018] Problems to be Solved by the Invention

[0019] The present invention has been made in view of the above circumstances, and the problem is to provide a plated steel sheet excellent in both planar corrosion resistance and end face corrosion resistance.

[0020] Means for Solving the Problems

[0021] In order to solve the above problems, the present invention adopts the following configuration.

[0022] [1] A plated steel sheet comprising a steel sheet and a plating layer disposed on the surface of the steel sheet,

[0023] The chemical composition of the plating layer contains, in mass %,

[0024] Al: 10.0 to 25.0%,

[0025] Mg: 3.0 to 10.0%,

[0026] Fe: 0.01 to 2.00%,

[0027] Si: more than 0.00% and 2.00% or less, and

[0028] one or more selected from the following Group A, Group B, and Group C,

[0029] The balance contains Zn and impurities,

[0030] When the plating layer is subjected to grazing incidence X-ray diffraction measurement using Cu-Kα rays under the conditions that the acceleration voltage as the X-ray output is set to 50 kV and the X-ray incident angle with respect to the surface of the plating layer is set to 1°, Mg 21 Zn 25 The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) exceeds 0.3.

[0031] [Group A]

[0032] Ni: 0 to 1.000%

[0033] [Group B]

[0034] Ca: 0 to 0.05%

[0035] [Group C]

[0036] Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, La: 0 to 0.50%, Ce: 0 to 0.50%, B: 0 to 0.50%, Y: 0 to 0.50%, P: 0 to 0.50%, Sr: 0 to 0.50%, Co: 0 to 0.500%, Bi: 0 to 0.500%, In: 0 to 0.500%, V: 0 to 0.500% and W: 0 to 0.500%, one or more of which: total is 0 to 5.000%

[0037] [2] The coated steel sheet according to [1], wherein the chemical composition of the above coating contains Mg: 4.5% or more by mass,

[0038] The above X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 1.0 or more.

[0039] [3] The coated steel sheet according to [1], wherein the chemical composition of the above coating contains Mg: 4.5% or more by mass,

[0040] The above X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 5.0 or more.

[0041] [4] The coated steel sheet according to [1], wherein the chemical composition of the above coating contains Mg: 4.5% or more by mass,

[0042] The above X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 10.0 or more.

[0043] [5] The coated steel sheet according to any one of [1] to [4], wherein the chemical composition of the above coating contains Sn: 0.05 to 0.5% by mass,

[0044] In the X-ray diffraction measurement of the above coating by the θ-2θ method, the Mg2Sn phase is detected in the above coating.

[0045] [6] The coated steel sheet according to any one of [1] to [4], wherein the chemical composition of the above coating contains the above Group A.

[0046] [7]The plated steel sheet according to any one of [1] to [4], wherein the chemical composition of the coating contains the above-mentioned Group B.

[0047] [8]The plated steel sheet according to any one of [1] to [4], wherein the chemical composition of the coating contains the above-mentioned Group C.

[0048] Advantageous Effects of the Invention

[0049] According to the present invention, a plated steel sheet excellent in both planar corrosion resistance and end face corrosion resistance can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a cross-sectional schematic view of a hot-dip galvanized steel material as an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0051] When the plated steel sheet is cut, the end face of the steel sheet is exposed at the cut end face of the plated steel sheet. The corrosion resistance of the end face of the steel sheet (hereinafter referred to as end face corrosion resistance) is generally achieved by the following operation. That is, it is achieved by the following method: A coating containing an element (such as Zn, Mg, etc.) having a higher ionization tendency than the base metal is formed on the surface of the steel sheet as a coating, and the coating is preferentially corroded with respect to the base metal to generate corrosion products, and the end face of the steel sheet is protected from corrosion by using the corrosion products. Therefore, the improvement of the end face corrosion resistance brought by the coating and the improvement of the corrosion resistance of the coating itself, that is, the planar corrosion resistance, are in an incompatible relationship.

[0052] Then, the inventors of the present invention conducted in-depth research to improve both the planar corrosion resistance and the end face corrosion resistance of the coating containing Al and Mg. In the coating containing Al, Mg, Si, and Zn, various Mg-Zn compounds containing Mg and Zn are formed. Mg in such Mg-Zn compounds 21 Zn 25 contains a relatively large amount of Mg that can contribute to the corrosion resistance of the end face of the steel sheet. The inventors of the present invention further studied this Mg 21 Zn 25 and found that by adjusting the manufacturing conditions of the coating, a large amount of Mg 21 Zn 25 can be crystallized in the surface layer of the coating, thereby improving the end face corrosion resistance. By the presence of a large amount of Mg 21 Zn 25 phase on the surface of the coating, Mg 21 Zn 25 phase is corroded from the initial stage of the corrosion of the coating. Along with the corrosion of the Mg 21 Zn 25 phase, Mg ions are generated as corrosion products, and the Mg ions protect the end face of the steel sheet from corrosion.

[0053] In addition, since a large amount of Mg exists on the surface of the plating layer 21 Zn 25 phases, it is possible to improve the end face corrosion resistance brought about by the corrosion products of the Mg 21 Zn 25 phases from the initial stage of corrosion. Therefore, it is possible to improve the end face corrosion resistance without sacrificing the planar corrosion resistance of the plating layer. Thus, it is possible to achieve both the planar corrosion resistance and the end face corrosion resistance of the plating layer.

[0054] Hereinafter, a plated steel sheet as an embodiment of the present invention will be described.

[0055] The plated steel sheet of the present embodiment includes a steel sheet and a plating layer disposed on the surface of the steel sheet. The chemical composition of the plating layer contains, by mass%, Al: 10.0 to 25.0%, Mg: 3.0 to 10.0%, Fe: 0.01 to 2.00%, Si: more than 0.00% and 2.00% or less, and further contains one or more selected from the following Group A, Group B, and Group C. The balance contains Zn and impurities. When the grazing incidence X-ray diffraction measurement of the plating layer is performed using Cu-Kα rays under the conditions that the acceleration voltage as the X-ray output is set to 50 kV and the X-ray incident angle with respect to the surface of the plating layer is set to 1°, the X-ray diffraction intensity ratio (I(Mg 21 Zn 25 ) / I(η-Zn)) of the (300) plane of the phase and the (002) plane of the η-Zn phase exceeds 0.3. 21 Zn 25 ) exceeds 0.3.

[0056] [Group A] Ni: 0 to 1.000%

[0057] [Group B] Ca: 0 to 0.05%

[0058] [Group C] One or more of Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, La: 0 to 0.50%, Ce: 0 to 0.50%, B: 0 to 0.50%, Y: 0 to 0.50%, P: 0 to 0.50%, Sr: 0 to 0.50%, Co: 0 to 0.500%, Bi: 0 to 0.500%, In: 0 to 0.500%, V: 0 to 0.500%, and W: 0 to 0.500%: The total is 0 to 5.000%

[0059] In the following description, "%" representing the content of each element of the chemical composition means "mass %". For the numerical range limited by clamping "~" described below, the lower limit value and the upper limit value are included in this range. For the values expressed as "less than" or "exceeding", the value is not included in the numerical range.

[0060] The content of the element of the chemical composition is sometimes described as the element concentration (such as Zn concentration, Mg concentration, etc.). "Flat corrosion resistance" represents the property of the plating layer (specifically, the Zn-Al-Mg alloy layer) itself being not easily corroded. "End face corrosion resistance" represents the property of suppressing the corrosion of the steel sheet at the exposed part of the steel sheet (such as the cut end face of the plated steel sheet). "Plating layer" refers to the plating film manufactured by the so-called hot-dip plating process.

[0061] As Figure 1 shown in, the plated steel sheet 1 of the present embodiment has a steel sheet 11. There is no particular limitation on the shape of the steel sheet 11. In addition, the steel sheet 11 can also be, for example, a base steel sheet formed into a steel pipe, a civil engineering building material (such as a grid channel, a corrugated pipe, a drain cover, a sand-proof plate, a bolt, a wire mesh, a guardrail, a waterproof wall, etc.), a home appliance component (such as the housing of the outdoor unit of an air conditioner), an automobile part (such as a running component), etc. The forming process is various plastic processing methods such as pressing, roll forming, and bending.

[0062] There is no particular limitation on the material of the steel sheet 11. The steel sheet 11 can be set as various steel sheets such as general steel, Al-killed steel, extra-low carbon steel, high carbon steel, various high-tensile steels, and some high alloy steels (such as steels containing strengthening elements such as Ni and Cr). The steel sheet 11 can also be set as the hot-rolled steel sheet, hot-rolled steel strip, cold-rolled steel sheet, and cold-rolled steel strip described in JIS G 3302:2010. There is also no particular limitation on the manufacturing method of the steel sheet (such as the hot-rolling method, pickling method, cold-rolling method, etc.) and its specific manufacturing conditions.

[0063] As described below, for the steel sheet that becomes the plating base plate, a steel sheet 11 with adjusted surface roughness is used. The adjustment of the surface roughness of the steel sheet can be carried out, for example, by the following method: setting the surface of the roll or the roll for skin pass rolling to a specified surface roughness and transferring the surface shape of the roll during rolling or skin pass rolling.

[0064] The coated steel sheet 1 of the present embodiment has a coating layer 12 disposed on the surface of the steel sheet 11. The coating layer 12 of the coated steel sheet 1 of the present embodiment is mainly composed of a Zn-Al-Mg alloy layer due to the chemical composition described later. In addition, the coating layer 12 of the coated steel sheet 1 of the present embodiment may include an interfacial alloy layer mainly composed of Fe and Al between the steel sheet 11 and the Zn-Al-Mg alloy layer. That is, the coating layer 12 may have a single-layer structure of a Zn-Al-Mg alloy layer or a laminated structure including a Zn-Al-Mg alloy layer and an interfacial alloy layer.

[0065] The chemical composition of the coating layer of the present embodiment is composed of Zn and other alloying elements. The chemical composition of the coating layer will be described in detail below. It should be noted that an element with a lower limit of concentration described as 0% is an optional element, which is not necessary to solve the problems of the coated steel sheet of the present embodiment, but is allowed to be included in the coating layer for the purpose of improving characteristics and the like.

[0066] <Al: 10.0 to 25.0%>

[0067] Al contributes to the improvement of flat corrosion resistance, edge corrosion resistance and workability. Therefore, the Al concentration is set to 10.0% or more. The Al concentration can also be set to 11.0% or more, 12.0% or more, or 15.0% or more. On the other hand, when the Al is excessive, the Mg concentration and the Zn concentration are relatively reduced, and the edge corrosion resistance deteriorates. Thus, the Al concentration is set to 25.0% or less. The Al concentration can also be set to 24.0% or less, 22.0% or less, or 20.0% or less.

[0068] <Mg: 3.0 to 10.0%>

[0069] Mg is an element necessary to ensure flat corrosion resistance and edge corrosion resistance. Therefore, the Mg concentration is set to 3.0% or more. The Mg concentration can also be set to 4.0% or more, 5.0% or more, or 6.0% or more. On the other hand, if the Mg concentration is excessive, the workability, especially the powdering property, may deteriorate, and further the flat corrosion resistance may deteriorate. Thus, the Mg concentration is set to 10.0% or less. The Mg concentration can also be set to 8.0% or less or 7.0% or less.

[0070] <Fe: 0.01 to 2.00%>

[0071] The concentration of Fe can also be 0%, but the coating may also contain more than 0.01% of Fe. It has been confirmed that if the Fe concentration is 2.00% or less, it has no adverse effect on the properties of the coating. The Fe concentration can also be set, for example, at 0.05% or more, 0.10% or more, 0.50% or more, or 1.00% or more. The Fe concentration is set at 2.00% or less. The Fe concentration can also be set at 1.80% or less or 1.50% or less. Since Fe may be mixed in from the base steel plate, the Fe concentration can also be 0.05% or more.

[0072] <Si: More than 0.00% and 2.00% or less>

[0073] Si contributes to the improvement of planar corrosion resistance. Therefore, the Si concentration can also be set at more than 0.00%, 0.01% or more, 0.02% or more, or 0.06% or more. On the other hand, if the Si concentration is excessive, the planar corrosion resistance and the end face corrosion resistance deteriorate. Therefore, the Si concentration is set at 2.00% or less. The Si concentration can also be set at 1.80% or less, 1.60% or less, 1.20% or less, or 1.00% or less.

[0074] Furthermore, the coating of the present embodiment may also contain one or more selected from the following Group A, Group B, and Group C.

[0075] [Group A] Ni: 0 to 1.000%

[0076] [Group B] Ca: 0 to 0.05%

[0077] [Group C] One or more selected from Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, La: 0 to 0.50%, Ce: 0 to 0.50%, B: 0 to 0.50%, Y: 0 to 0.50%, P: 0 to 0.50%, Sr: 0 to 0.50%, Co: 0 to 0.500%, Bi: 0 to 0.500%, In: 0 to 0.500%, V: 0 to 0.500%, and W: 0 to 0.500%: Total is 0 to 5.000%

[0078] <Ni: 0 to 1.000%>

[0079] The concentration of Ni in Group A can also be 0%. On the other hand, Ni contributes to the improvement of the end face corrosion resistance. Therefore, the Ni concentration can also be set to 0.050% or more, 0.080% or more, or 0.100% or more. On the other hand, if the Ni concentration is excessive, the planar corrosion resistance deteriorates. Therefore, the Ni concentration is set to 1.000% or less. The Ni concentration can also be set to 0.800% or less, 0.600% or less, 0.500% or less, 0.100% or less, or 0.010% or less.

[0080] <Ca: 0 to 0.05%>

[0081] The concentration of Ca in Group B can also be 0%. On the other hand, Ca is an element that can adjust the amount of Mg dissolution that is optimal for imparting planar corrosion resistance. Therefore, the Ca concentration can also be 0.005% or more or 0.01% or more. On the other hand, if the Ca concentration is excessive, the planar corrosion resistance and workability deteriorate. Therefore, the Ca concentration is set to 0.05% or less. The Ca concentration can also be set to 0.04% or less.

[0082] Furthermore, in the coating of the present embodiment, as Group C, it may also contain one or more elements selected from Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, La: 0 to 0.50%, Ce: 0 to 0.50%, B: 0 to 0.50%, Y: 0 to 0.50%, P: 0 to 0.50%, Sr: 0 to 0.50%, Co: 0 to 0.500%, Bi: 0 to 0.500%, In: 0 to 0.500%, V: 0 to 0.500%, and W: 0 to 0.500%. The total of these elements is set to 0 to 5.000%. If the total exceeds 5.000%, the planar corrosion resistance or end face corrosion resistance may decrease.

[0083] <Sb, Pb: 0 to 0.50% respectively>

[0084] The concentrations of Sb and Pb can also be 0%. On the other hand, Sb and Pb contribute to the improvement of the end face corrosion resistance. Therefore, the concentrations of Sb and Pb can also be set to 0.05% or more, 0.10% or more, or 0.15% or more. On the other hand, if the concentrations of Sb and Pb are excessive, the planar corrosion resistance deteriorates. Therefore, the concentrations of Sb and Pb are set to 0.50% or less. The concentrations of Sb and Pb can also be set to 0.40% or less, 0.30% or less, 0.25% or less, or 0.10% or less.

[0085] <Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li: 0 to 1.00% respectively>

[0086] The concentrations of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li can also be 0% respectively. On the other hand, they contribute to the improvement of the end face corrosion resistance. Therefore, the concentrations of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li can also be set to 0.05% or more, 0.08% or more, or 0.10% or more respectively. On the other hand, if the concentrations of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li are excessive, the planar corrosion resistance deteriorates. Therefore, the concentrations of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li are set to 1.00% or less respectively. The concentrations of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag and Li can also be set to 0.80% or less, 0.70% or less, 0.60% or less, 0.10% or less, or 0.05% or less respectively.

[0087] <Sn: 0 to 1.00%>

[0088] The Sn concentration can also be 0%. On the other hand, Sn is an element that forms an intermetallic compound with Mg and improves the end face corrosion resistance of the coating. Therefore, the Sn concentration can also be set to 0.05% or more, 0.10% or more, or 0.20% or more. However, if the Sn concentration is excessive, the planar corrosion resistance deteriorates. Therefore, the Sn concentration is set to 1.00% or less. The Sn concentration can also be set to 0.80% or less, 0.60% or less, 0.50% or less, or 0.10% or less.

[0089] <La, Ce, B, Y, P and Sr: 0 to 0.50% respectively>

[0090] The concentrations of La, Ce, B, Y, P and Sr can also be 0% respectively. On the other hand, La, Ce, B, Y, P and Sr contribute to the improvement of the end face corrosion resistance. Therefore, the concentrations of La, Ce, B, Y, P and Sr can also be set to 0.10% or more, 0.15% or more, or 0.20% or more respectively. On the other hand, if the concentrations of La, Ce, B, Y, P and Sr are excessive, the planar corrosion resistance deteriorates. Therefore, the concentrations of La, Ce, B, Y, P and Sr are set to 0.50% or less respectively. The concentrations of La, Ce, B, Y, P and Sr can also be set to 0.40% or less, 0.30% or less, 0.10% or less, or 0.05% or less respectively.

[0091] <Co, Bi, In, V, W: 0 to 0.500% respectively>

[0092] The concentration of each of Co, Bi, In, V, and W may also be 0%. On the other hand, Co, Bi, In, V, and W contribute to the improvement of the end face corrosion resistance. Therefore, the concentration of each of Co, Bi, In, V, and W can also be set to 0.100% or more, 0.150% or more, or 0.200% or more. On the other hand, if the concentration of Co, Bi, In, V, and W is excessive, the planar corrosion resistance deteriorates. Therefore, the concentration of each of Co, Bi, In, V, and W is set to 0.5% or less. The concentration of each of Co, Bi, In, V, and W can also be set to 0.400% or less, 0.300% or less, 0.100% or less, 0.050% or less, or 0.010% or less.

[0093] <The remainder: Zn and impurities>

[0094] The remainder of the composition of the coating layer of the present embodiment is Zn and impurities. Zn is an element that gives the coating layer planar corrosion resistance and end face corrosion resistance. Impurities refer to the components contained in the raw materials or the components mixed in during the manufacturing process, and are components that are not intentionally contained or do not cause adverse effects on the coated steel sheet of the present embodiment. For example, in the coating layer, it is possible that, through the mutual atomic diffusion between the base steel sheet and the plating bath, components other than Fe are also slightly mixed as impurities.

[0095] The chemical composition of the coating layer is measured by the following method. First, the coating layer is stripped and dissolved using an acid containing an inhibitor that suppresses the corrosion of the steel sheet to obtain an acid solution. Then, the obtained acid solution is subjected to ICP (inductively coupled plasma) analysis. Thereby, the chemical composition of the coating layer can be obtained. The type of acid is not particularly limited as long as it can dissolve the coating layer. It should be noted that the chemical composition measured by the above means is the average chemical composition of the entire coating layer.

[0096] Next, the metal structure of the coating layer will be described.

[0097] In the surface layer of the coating layer of the present embodiment, Mg 21 Zn 25 phase exists. The so-called surface layer of the coating layer is, strictly speaking, the depth region within the range where X-rays penetrate and diffraction lines can be obtained in the grazing incidence X-ray diffraction measurement with the incident angle of X-rays set to 1°. Approximately, it can also be referred to as the region from the outermost surface of the coating layer to a depth of 3 μm. The Mg 21 Zn 25 phase may also exist in regions other than the surface layer of the coating layer, but must be included in the surface layer. Due to the Mg 21 Zn 25 phase being located in the surface layer of the coating layer, at the initial stage of corrosion of the coating layer, Mg 21 Zn25 The phase is corroded to form a corrosion product, and the corrosion resistance of the end face of the steel plate is improved by this corrosion product. Thus, the end face corrosion resistance can be improved without impairing the planar corrosion resistance of the coating.

[0098] Mg 21 Zn 25 The presence of the phase is confirmed as follows: When performing grazing-incidence X-ray diffraction measurement on the coating under the conditions of using Cu-Kα rays, setting the acceleration voltage as the X-ray output to 50 kV, and setting the X-ray incident angle relative to the surface of the coating to 1°, Mg 21 Zn 25 phase is detected. 21 Zn 25 Specifically, the confirmation of the presence of the phase is carried out by confirming the presence or absence of the diffraction peak of the (300) plane of Mg 21 Zn 25 phase. 21 Zn 25 The diffraction peak of the (300) plane of Mg

[0099] It should be noted that regarding the judgment of the detection or non-detection of the Mg 21 Zn 25 phase, when the X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) exceeds 0.3, it can be said that the Mg 21 Zn 25 phase exists.

[0100] It should be noted that as described above, the Mg 21 Zn 25 phase only needs to exist in the surface layer of the coating, but the Mg 21 Zn 25 phase can also exist in areas other than the surface layer of the coating. That is, the Mg 21 Zn 25 phase can be detected by grazing-incidence X-ray diffraction measurement and also by X-ray diffraction measurement using the usual θ-2θ method. However, if a large amount of Mg 21 Zn 25 phase is formed in areas other than the surface layer of the coating, it is possible that the Mg 21 Zn 25There is little phase change, so it is necessary to appropriately control the cooling conditions during coating formation as described below.

[0101] It should be noted that the measurement method using grazing-incidence X-ray diffraction is also called small-angle incidence X-ray diffraction, grazing-incidence X-ray diffraction, and thin-film X-ray diffraction. In this method, different from the usual θ-2θ measurement method, X-ray diffraction measurement is performed by moving the X-ray detector while keeping the X-ray incident angle relative to the specimen fixed.

[0102] Mg in the surface of the coating 21 Zn 25 The number density of the phase may be affected by the average chemical composition of the coating. When the chemical composition of the coating contains Mg: 4.5% or more by mass, in the case of performing grazing-incidence X-ray diffraction measurement on the coating under the conditions of using Cu-Kα rays, setting the acceleration voltage as the X-ray output to 50 kV, and setting the X-ray incident angle relative to the surface of the coating to 1°, 21 Zn 25 the X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) of the (300) plane of the phase and the (002) plane of the η-Zn phase can also be 1.0 or more, can also be 5.0 or more, can also be 10.0 or more, can also be 15.0 or more, can also be 20.0 or more. By setting the above X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) to a higher value, it is possible to balance the planar corrosion resistance and the end-face corrosion resistance at a higher level.

[0103] It should be noted that I(Mg 21 Zn 25 ) is the peak intensity of the diffraction peak of the (300) plane of the Mg 21 Zn 25 phase. More specifically, it is set to the maximum diffraction intensity within the range of the diffraction angle of 11.92° ± 0.4°. I(η-Zn) is the peak intensity of the diffraction peak of the (002) plane of the η-Zn phase. More specifically, it is set to the maximum diffraction intensity within the range of the diffraction angle of 36.24° ± 0.4°.

[0104] The η-Zn phase is a metal phase that exists relatively abundantly not only in the surface layer but also throughout the coating in the chemical composition of the coating in this embodiment. Therefore, it is appropriate to use the diffraction intensity of the η-Zn phase as a reference. The higher the ratio of the diffraction intensity of the Mg 21 Zn 25 phase to the diffraction intensity of the η-Zn phase, the more it can be said that Mg is contained more in the surface layer of the coating21 Zn 25 phase. By including a large amount of Mg in the surface layer of the coating 21 Zn 25 phase, more Mg 21 Zn 25 phase corrosion products are formed at the initial stage of coating corrosion, thereby further improving the corrosion resistance of the end face of the steel sheet.

[0105] There is no particular limitation on the upper limit of I(Mg 21 Zn 25 ) / I(η-Zn), but for example, it can also be set to 50.0 or less, 45.0 or less, 40.0 or less, 35.0 or less, 30.0 or less.

[0106] The measurement method for the diffraction intensities of the Mg 21 Zn 25 phase and the η-Zn phase is described. Using an X-ray diffractometer (manufactured by Rigaku Corporation (model RINT1500)), with X-ray output: (acceleration voltage) 50 kV, (acceleration current) 200 mA, X-ray source: copper target, X-ray irradiation angle: 1°, accessory: using a rotating specimen stage for thin films, filter: none, monochromator: used, under the conditions, grazing incidence X-ray diffraction measurement is carried out in the range of 2θ = 5 to 90°. Then, the diffraction intensities of the (300) plane of the Mg 21 Zn 25 phase (the maximum intensity in the range of 11.92° ± 0.4°) and the diffraction intensity of the (002) plane of the η-Zn phase (the maximum intensity in the range of 36.24° ± 0.4°) are measured respectively. The diffraction intensity is set to the intensity after removing the background intensity. From the obtained diffraction intensities, I(Mg 21 Zn 25 ) / I(η-Zn) is obtained. It should be noted that as the measurement conditions, as long as the acceleration voltage: 50 kV, X-ray source: Cu, and X-ray incident angle: 1° are satisfied, even if other measurement conditions are different, it has no influence on the detection of the Mg 21 Zn 25 phase, and the diffraction intensity ratio of the Mg 21 Zn 25 phase and the η-Zn phase.

[0107] In addition, when the coating contains 0.05 to 0.5% of Sn, it is preferable to include the Mg2Sn phase in the coating. Since the amount of the Mg2Sn phase is small, its presence is detected / confirmed by X-ray diffraction measurement using the θ-2θ method. By including the Mg2Sn phase in the coating, the end face corrosion resistance of the coating is further improved. The X-ray diffraction measurement for detecting the Mg2Sn phase may be performed by the θ-2θ measurement method. In addition, the X-ray diffraction measurement uses the Kα ray of a Cu tube target, and when a peak is detected at 23.4 ± 0.3°, it is determined that the Mg2Sn phase is present.

[0108] The coating amount per single side of the coating is set, for example, within the range of 20 to 150 g / m 2 That's all right. By setting the coating amount per single side to 20 g / m 2 or more, the planar corrosion resistance and end face corrosion resistance of the coated steel sheet can be further improved. On the other hand, by setting the coating amount per single side to 150 g / m 2 or less, the workability of the coated steel sheet can be further improved.

[0109] Next, a method for manufacturing the coated steel sheet of the present embodiment will be described. However, the method for manufacturing the coated steel sheet of the present embodiment is not particularly limited. For example, according to the manufacturing conditions described below, the coated steel sheet of the present embodiment can be obtained.

[0110] The method for manufacturing the coated steel sheet of the present embodiment forms a coating on the surface of the steel sheet by annealing the steel sheet with adjusted surface roughness in a reducing atmosphere, dipping the annealed steel sheet into a hot-dip plating bath and then lifting it out. Then, a cooling gas is blown during the period when the temperature of the coating drops from the bath temperature to 300 °C or lower for cooling. Regarding the gas flow rate when blowing the cooling gas, the gas flow rate from the bath temperature to the controlled cooling temperature is set within the range of 5000 to 80000 L / min / m 2 The range, and the gas flow rate from the controlled cooling temperature to 300 °C or lower is set within the range of 0 to 5000 L / min / m 2 Range.

[0111] The controlled cooling temperature is set to a temperature within the range of -10 °C to -30 °C relative to the crystallization temperature of the Mg 21 Zn 25 Phase.

[0112] The surface roughness of the steel sheet that becomes the plating base material is set to 0.1 to 3.5 μm in terms of the arithmetic surface roughness Ra. If it is out of this range, a large amount of Mg may crystallize near the interface between the coating and the steel sheet 21 Zn 25 Phase, and Mg at the surface of the coating 21 Zn25 The reduction is mutual. There is no particular limitation on the adjustment of the surface roughness of the steel plate. For example, it can also be adjusted by the following method: using a roll whose roll surface is adjusted to the desired roughness or a roll for temper rolling to roll the plating base plate and transfer the surface shape of the roll. In addition, it can also be adjusted by pickling.

[0113] The measurement of the arithmetic mean roughness is carried out, for example, using a shape measurement laser microscope (model: VK-8700) manufactured by KEYENCE CORPORATION. As the measurement conditions, for example, it is set as the measurement mode: laser confocal, measurement quality: high precision, pitch: 0.75 μm, double scan: on, optical zoom: 1×, objective lens name: plan achromat (Plan), γ coefficient: 0.45, offset: 0%, and the measurement is carried out. It should be noted that the measurement device used in the measurement of the arithmetic mean roughness is not limited to the above example.

[0114] The annealing of the steel plate that becomes the plating base plate is carried out in a reducing atmosphere. The reducing atmosphere and annealing conditions are not particularly limited. Through this annealing, the oxides existing on the surface of the steel plate are removed as much as possible.

[0115] Next, the annealed steel plate is immersed in a hot dip plating bath. The chemical composition of the hot dip plating bath can be appropriately adjusted as long as it can obtain the chemical composition of the above-mentioned coating. In addition, the temperature of the hot dip plating bath is not particularly limited, and the temperature at which hot dip plating can be carried out can be appropriately selected. For example, the bath temperature can also be set to a value about 20 °C or more higher than the melting point of the plating bath.

[0116] Next, the steel plate is lifted out of the hot dip plating bath. By controlling the lifting speed of the steel plate, the coating adhesion amount can be controlled. If necessary, the steel plate with the coating attached can also be wiped to control the coating adhesion amount. The coating adhesion amount is not particularly limited, and for example, it can be set within the above range.

[0117] Next, the coating is cooled. The cooling is to blow cooling gas on the steel plate just lifted out of the hot dip plating bath. The cooling by blowing the cooling gas is continuously carried out during the period when the temperature of the steel plate drops from the bath temperature to 300 °C. The cooling conditions below 300 °C are not particularly limited. Subsequently, cooling by blowing the cooling gas can be carried out, or natural air cooling can be carried out.

[0118] In the cooling by blowing the cooling gas, it is carried out by arranging a cooling belt along the conveyance path of the steel sheet. In the cooling belt, a plurality of blowing nozzles for the cooling gas are provided. The shape of the gas nozzle for ejecting the cooling gas is set, for example, in the range of 1 to 50 mm in diameter. The angle formed by the front end of the gas nozzle and the steel sheet is set, for example, in the range of 70 to 110°, and more preferably 90° (right angle). The distance between the front end of the gas nozzle and the steel sheet is set in the range of 30 to 1000 mm. It should be noted that the shape, angle, and distance of the gas nozzle are merely an example and are not limited to the above ranges.

[0119] The blown cooling gas is not particularly limited and may be a non-oxidizing gas such as nitrogen, an inert gas such as argon, or air, or a mixed gas thereof.

[0120] In the present embodiment, the gas flow rate when blowing the cooling gas is controlled in two stages. That is, based on the temperature of the steel sheet, the gas flow rate from the plating bath temperature to the controlled cooling temperature (a temperature in the range of -10 to -30°C with respect to the crystallization temperature of the Mg 21 Zn 25 phase) is set in the range of 5000 to 80000 L / min / m 2 and the gas flow rate from the controlled cooling temperature to 300°C or lower is set in the range of 0 to 5000 L / min / m 2 The controlled cooling temperature is the temperature presumed to be the crystallization start temperature of the Mg 21 Zn 25 phase.

[0121] The gas flow rate can be adjusted by changing the shape of the gas nozzle, controlling the output of the compressor, etc.

[0122] When the gas flow rate is set in the range lower than 5000 L / min / m 2 , it is possible to prevent the surface of the plating during cooling from vibrating. On the other hand, when the gas flow rate is set in the range of 5000 L / min / m 2 or higher, it becomes possible to give a minute vibration to the surface of the plating during cooling.

[0123] Moreover, by setting the gas flow rate from the plating bath temperature to the controlled cooling temperature in the range of 5000 to 80000 L / min / m 2 , a vibration is given to the surface of the plating, and the nucleation of the Mg 21 Zn 25 phase is promoted on the surface of the plating. Then, by setting the gas flow rate from the controlled cooling temperature to 300°C or lower in the range of 0 to 5000 L / min / m 2 , the Mg 21Zn 25 The phase further grows. If the range of the gas flow deviates from the above range, it becomes difficult to crystallize Mg on the surface of the coating layer. 21 Zn 25 phase.

[0124] It should be noted that preferably, the gas flow from the controlled cooling temperature to 300 °C or lower is set to a lower value compared to the gas flow from the plating bath temperature to the controlled cooling temperature. When the gas flow in the two temperature regions is set to be constant (the gas flow from the plating bath temperature to the controlled cooling temperature is set to 5000 L / min / m 2 , and the gas flow from the controlled cooling temperature to 300 °C or lower is set to 5000 L / min / m 2 ), it is preferable to set the average cooling rates in the two temperature regions to different values. By setting such conditions, it is possible to preferably generate Mg 21 Zn 25 phase in the surface layer of the coating layer.

[0125] Mg 21 Zn 25 The crystallization temperature of the phase varies depending on the chemical composition of the plating bath, so it is calculated using a calculated phase diagram. Specifically, the thermodynamic data of intermetallic compound phases, metal phases, etc. that can be included in the Al-Mg-Zn alloy system are collected to construct a calculated phase diagram database, and by calculating using the CALPHAD method (Calculation of Phase Diagram), the Mg 21 Zn 25 phase crystallization temperature is obtained for each chemical composition of the plating bath. More specifically, by using the thermodynamic equilibrium calculation software "Thermo-Calc" (Thermo-Calc is a registered trademark, manufactured by Thermo-Calc Software AB), the Mg 21 Zn 25 phase crystallization temperature can be estimated. It should be noted that the thermodynamic equilibrium calculation software used in the calculation is not limited to "Thermo-Calc" (registered trademark), and other software can also be used. The temperature within the range of -10 to -30 °C with respect to the obtained Mg 21 Zn 25 phase crystallization temperature is used as the controlled cooling temperature.

[0126] In the above manufacturing method, by pre-adjusting the surface roughness of the steel plate surface, the nucleation of the Mg 21 Zn 25 phase near the interface between the steel plate and the coating layer can be suppressed, and thus the Mg near the interface between the coating layer and the steel plate can be suppressed.21 Zn 25 Crystallization of the phase. By hot-dip coating such a steel sheet and then controlling the cooling conditions after coating as described above, a large amount of Mg is crystallized on the surface of the coating layer. 21 Zn 25 phase. Thus, it is speculated that a large amount of Mg can be formed on the surface of the coating layer. 21 Zn 25 phase.

[0127] It should be noted that as long as the necessary conditions shown in the present invention are satisfied, the manufacturing method of the coated steel sheet is not limited to the above content. Instead of the hot-dip coating method, electroplating, evaporation coating, spraying, cold spraying, etc. can also be used.

[0128] Examples

[0129] Hereinafter, examples of the present invention will be described. However, the conditions in the examples are merely a conditional example adopted to confirm the feasibility and effects of the present invention. The present invention is not limited to this conditional example. As long as it does not deviate from the gist of the present invention and achieves the purpose of the present invention, the present invention can adopt various conditions.

[0130] For the coating base plate, a cold-rolled steel sheet (0.05C - 0.1Si - 0.2Mn) with a thickness of 2.3 mm was used. The surface roughness of a part of the coating base plate was controlled using a skin pass mill or the like. The steel sheet with adjusted surface roughness was annealed. By immersing the annealed steel sheet in various hot-dip coating baths and then lifting it out, a coating layer was adhered to the surface of the steel sheet. Then, by using cooling gas for cooling during the period from just lifting out of the coating bath until the coating layer reached 300 °C, various coated steel sheets were manufactured.

[0131] The arithmetic mean roughness Ra of the surface of the steel sheet that becomes the coating base plate was set as described in the table.

[0132] The measurement of the arithmetic mean roughness was carried out using a shape measurement laser microscope (model: VK-8700) manufactured by KEYENCE Corporation. As the measurement conditions, the measurement mode was set to: laser confocal, the measurement quality was set to: high precision, the pitch was set to: 0.75 μm, double scanning was set to: on, the optical zoom was set to: 1 time, the objective lens name was set to: planachromat (Plan), the γ coefficient was set to: 0.45, and the offset was set to: 0%, and the measurement was carried out.

[0133] Regarding the annealing conditions when annealing the steel plate in a reducing atmosphere, the soaking temperature is set at 600°C and the soaking time is set at 10 seconds. The annealing atmosphere is set as a reducing atmosphere of a mixed gas containing 5% hydrogen and the remaining part nitrogen. Then, after air-cooling the annealed steel plate with nitrogen until the temperature of the immersion plate reaches the bath temperature + 20°C, it is immersed in the hot-dip plating bath and then lifted. The lifting speed is set at 20 - 200 mm / second.

[0134] The chemical composition of the coating is as shown in Table 1. The manufacturing conditions are set as shown in Table 2. In addition, the metallographic structure of the coating is evaluated, and the results are shown in Table 3. Furthermore, the planar corrosion resistance and edge corrosion resistance of the plated steel sheet are evaluated, and the results are shown in Table 3.

[0135] The evaluation of the chemical composition of the coating and the metallographic structure of the coating is carried out by the above means.

[0136] The evaluation of planar corrosion resistance is set as follows. The obtained hot-dip galvanized steel is cut into 100 mm × 50 mm and used for the planar corrosion resistance evaluation test. The evaluation of planar corrosion resistance is carried out by the corrosion promotion test specified in JASO-CCT-M609 and is carried out by comparing the corrosion weight loss after 90 cycles. The evaluation criteria are set as follows, and "AAA", "AA" and "A" are set as qualified.

[0137] AAA: Corrosion weight loss is less than 30 g / m 2

[0138] AA: Corrosion weight loss is 30 g / m 2 or more and less than 60 g / m 2

[0139] A: Corrosion weight loss is 60 g / m 2 or more and less than 90 g / m 2

[0140] B: Corrosion weight loss is 90 g / m 2 or more

[0141] The edge corrosion resistance is set as follows. The obtained hot-dip galvanized steel is cut into a size of 50 mm × 50 mm to make a square test piece. Then, the coating in the area with a diameter of 15 mm centered on the intersection of the diagonals of the test piece is removed by milling to form an exposed area of the steel plate (base metal). A neutral salt spray test specified in JIS Z 2371:2015 is carried out on the exposed area of the base metal with a diameter of 15 mm, and the evaluation is carried out based on the red rust generation condition of the exposed area of the base metal. The following shows the evaluation criteria for the red rust area ratio. "AAA", "AA" and "A" are set as qualified.

[0142] AAA: The red rust area ratio is 10% or less at 1300 h

[0143] AA: The red rust area ratio is 10% or less at 800 h

[0144] A: The red rust area ratio is 20% or less at 400 h

[0145] B: The red rust area ratio exceeds 20% at 400 h

[0146] As shown in Tables 1 to 3, both the planar corrosion resistance and the end face corrosion resistance of Examples 1 to 27 of the present invention, in which the chemical composition and metal structure of the coating are appropriately controlled, are excellent. It should be noted that the coating amount per single side of the coating in the examples is in the range of 20 to 150 g / m 2 range.

[0147] For Comparative Example 28, the Al content in the coating is insufficient. Therefore, for Comparative Example 28, the planar corrosion resistance is insufficient.

[0148] For Comparative Example 29, the Al content in the coating is excessive. Therefore, for Comparative Example 29, although Mg 21 Zn 25 phase crystallizes, the end face corrosion resistance decreases.

[0149] For Comparative Example 30, the Mg content in the coating is insufficient. Therefore, for Comparative Example 30, Mg is insufficient and no Mg 21 Zn 25 phase crystallizes, and the planar corrosion resistance and the end face corrosion resistance decrease.

[0150] For Comparative Example 31, the Mg content in the coating is excessive. Therefore, for Comparative Example 31, a large amount of low-potential Mg-Zn phase is generated excessively, and the planar corrosion resistance decreases.

[0151] For Comparative Example 32, the cooling gas flow rate from the bath temperature to the controlled cooling temperature is insufficient. Therefore, for Comparative Example 32, no Mg 21 Zn 25 phase can crystallize, and the end face corrosion resistance decreases.

[0152] For Comparative Example 33, the cooling gas flow rate from the controlled cooling temperature to 300 °C is excessive. Therefore, for Comparative Example 33, a large amount of Mg 21 Zn 25 phase crystallizes inside the coating, and no Mg 21 Zn 25 phase crystallizes on the surface layer of the coating, and the end face corrosion resistance decreases.

[0153] In Comparative Example 34, the arithmetic mean roughness Ra of the surface of the steel sheet that is the plating base plate deviated from the preferred range. Therefore, a large amount of Mg 21 Zn 25 phases crystallized near the interface between the coating and the steel sheet, and the amount of Mg 21 Zn 25 phases on the surface of the coating decreased, and the end face corrosion resistance decreased.

[0154] In Comparative Example 35, the cooling gas flow rate from the control cooling temperature to 300 °C was excessive. Therefore, in Comparative Example 35, no Mg 21 Zn 25 phases crystallized in the surface layer of the coating, and the end face corrosion resistance decreased.

[0155] In Comparative Example 36, the Al content of the coating was excessive. Therefore, in Comparative Example 29, no Mg 21 Zn 25 phases crystallized in the surface layer of the coating, and the planar corrosion resistance decreased.

[0156] [Table 1]

[0157]

[0158] The underlined part indicates deviation from the scope of the present invention.

[0159] [Table 2]

[0160]

[0161] The underlined part indicates deviation from the preferred manufacturing conditions.

[0162] [Table 3]

[0163]

[0164] The underlined part indicates deviation from the scope of the present invention.

[0165] Explanation of symbols

[0166] 1 Plated steel sheet, 11 Steel sheet, 12 Coating.

Claims

1. A plated steel sheet comprising a steel sheet and a plating layer disposed on the surface of the steel sheet, The chemical composition of the plating layer contains, by mass%: Al：10.0～25.0％、 Mg: 3.0 to 10.0%, Fe: 0.01 to 2.00%, Si: more than 0.00% and 2.00% or less, and One or more selected from the following Group A, Group B, and Group C, The balance contains Zn and impurities, In the case of performing grazing incidence X-ray diffraction measurement on the coating under the conditions of using Cu-Kα rays, setting the accelerating voltage as the X-ray output to 50 kV, and setting the X-ray incident angle with respect to the surface of the coating to 1°, Mg 21 Zn 25 The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) of the (300) plane of the phase and the (002) plane of the η-Zn phase exceeds 0.3, [Group A] Ni: 0 to 1.000% [Group B] Ca: 0 to 0.05% [Group C] Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, La: 0 to 0.50%, Ce: 0 to 0.50%, B: 0 to 0.50%, Y: 0 to 0.50%, P: 0 to 0.50%, Sr: 0 to 0.50%, Co: 0 to 0.500%, Bi: 0 to 0.500%, In: 0 to 0.500%, V: 0 to 0.500%, and W: 0 to 0.500%: The total is 0 to 5.000%.

2. The plated steel sheet according to claim 1, wherein, The chemical composition of the plating layer contains Mg: 4.5% or more by mass%, The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 1.0 or more.

3. The plated steel sheet according to claim 1, wherein, The chemical composition of the plating layer contains Mg: 4.5% or more by mass%, The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 5.0 or more.

4. The coated steel sheet according to claim 1, wherein, The chemical composition of the plating layer contains Mg: 4.5% or more by mass%, The X-ray diffraction intensity ratio (I(Mg 21 Zn 25 )) / I(η-Zn)) is 10.0 or more.

5. The plated steel sheet according to any one of claims 1 to 4, wherein, The chemical composition of the plating layer contains Sn: 0.05 to 0.5%, In the X-ray diffraction measurement of the plating layer using the θ-2θ method, the Mg2Sn phase is detected in the plating layer.

6. The plated steel sheet according to any one of claims 1 to 4, wherein, The chemical composition of the plating layer contains the Group A.

7. The plated steel sheet according to any one of claims 1 to 4, wherein, The chemical composition of the plating layer contains the Group B.

8. The plated steel sheet according to any one of claims 1 to 4, wherein, The chemical composition of the plating layer contains the Group C.

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