Plated steel material

Description

/ 38 PLATED STEEL MATERIAL TECHNICAL FIELD

[001] The present invention relates to a sheeted steel material. Priority is claimed in Japanese Patent Application No. 2023-064063, filed on April 11, 2023, the contents of which are incorporated herein by reference. FUNDAMENTALS OF THE TECHNIQUE

[002] A steel material on whose surface a Zn-containing Al and Mg clad layer is formed (a Zn-Al-Mg based clad steel material) has exceptional corrosion resistance. Therefore, Zn-Al-Mg based clad steel materials are widely used, for example, as a material for structural members requiring corrosion resistance, such as building materials.

[003] For example, Patent Document 1 describes a plated steel sheet including: a steel sheet; and a plated layer formed on a surface of the steel sheet, wherein the plated layer contains Al: 0 to 90% by mass and Mg: 0 to 10% by mass in terms of average composition, and the remainder containing Zn and an impurity; and a patterned part, arranged so as to have a certain shape, and a non-patterned part are formed on the plated layer, the patterned part and the non-patterned part each include one or two of a first region and a second region, the absolute value of the difference between the area fraction of the first region in the patterned part and the area fraction of the first region in the non-patterned part is 30% or more, and the first region has an orientation ratio of 3.5 or more and the second region has an orientation ratio of less than 3.5.

[004] Patent Document 2 describes a Zn-Al-Mg plated steel sheet including: a steel sheet; and a plated layer containing Al in an amount of 4% by mass or more and 22% Petition 870250088824, dated 09 / 30 / 2025, page 11 / 53 / 38 by mass or less, Mg in an amount of 1% by mass or more and 5% by mass or less, and the remainder containing Zn and an unavoidable impurity, wherein the cross-section of the plated layer, which is parallel to the surface of the plated layer, has a diffraction intensity ratio I(200) / I(111) of 0.8 or more, which is the ratio of the XI(200) plane diffraction intensity of the Al phase to the XI(111) plane diffraction intensity of the Al phase.

[005] In recent years, steel-clad materials for building materials used in roofing, wall materials, and the like have been required to be exceptional in red rust resistance to suppress the occurrence of red rust in base metals and in base metal corrosion resistance to suppress an increase in the depth of corrosion of the base metal when the base metal is exposed. However, in the related art, the improvement of red rust resistance and base metal corrosion resistance has been almost unstudied.

[006] Patent Document 1 describes that, where the first region means a region having an intensity ratio of 3.5 or more between the I0002 diffraction peak intensity of the (0002) plane and the I10-11 diffraction peak intensity of the (10-11) plane in the Zn phase, and the second region means a region having an intensity ratio that is less than 3.5, the difference between the area fraction of the first region in the patterned part and the area fraction of the first region in the non-patterned part is defined as 30% or more to intentionally express characters, designs and the like on the surface of the plated layer. However, red rust resistance and base metal corrosion resistance have not been examined.

[007] Patent Document 2 describes that, by controlling the orientation of the Al phase in the plated layer, the plated layer has an external appearance similar to that of a pear peel, which has a fine texture and many smooth and shiny parts. However, resistance to red rust Petition 870250088824, dated 09 / 30 / 2025, page 12 / 53 / 38 and the corrosion resistance of base metals were not examined. List of Citations Patent Document

[008] Patent Document 1: Japanese Patent Application No. Examined, First Publication No. 2021-85086

[009] Patent Document 2: International Publication PCT No. WO 2011 / 001662 SUMMARY OF THE INVENTION Technical Problem

[0010] The present invention was made in view of the above circumstances, and one objective thereof is to provide a plated steel material having exceptional resistance to red rust and resistance to corrosion of base metals. Solution to the Problem

[0011] In order to achieve the above objective, the present invention adopts the constitutions described below.

[0012] [1] A plated steel material including: a steel material; and a plating layer on the steel material, wherein the plating layer has a chemical composition containing, in terms of % by mass, Al: 6.0 to 30.0% Mg: 3.0 to 15.0% Fe: 0.01 to 15.00% Yes: 0 to 2.0% Ca: 0 to 2.00%, one or two of La and Ce: 0.005 to 0.500% in total, one or two or more elements selected from a group of elements of Sb: 0 to 0.50%, Pb: 0 to 0.50%, Cu: 0 to 1.00%, Sn: 0 to Petition 870250088824, dated 09 / 30 / 2025, page 13 / 53 / 38 1.00%, Ti: 0 to 1.00%, Cr: 0 to 1.00%, Nb: 0 to 1.00%, Zr: 0 to 1.00%, Ni: 0 to 1.000%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, B: 0 to 0.500%, 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 0.50%, V: 0 to 0.500% and W: 0 to 0.50%, in a total quantity of 0 to 5.0%, and the remainder: Zn is an impurity, and the plated layer has a diffraction intensity obtained from an X-ray diffraction measurement result, the diffraction intensity satisfying formula (1) below: 0.15 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} < 3.00 ••• (1) in formula (1), I(100)Zn represents a diffraction intensity of the η-Zn (100) phase, I(002)Zn represents a diffraction intensity of the n-Zn(002) phase, I(101)Zn represents a diffraction intensity of the ηZn (101) phase, and I(100)Zn represents a diffraction intensity of the η-Zn (100) phase.

[0013] [2] The steel plated material according to [1], wherein Al and Mg in the plated layer are Al: 10.0 to 25.0% and Mg: 4.5 to 15.0%, respectively.

[0014] [3] The steel plated material according to [1] or [2], wherein a total of one or two of La and Ce in the plated layer is from 0.010 to 0.500%, and a number of one or more of an intermetallic compound phase containing LaCe, an intermetallic compound phase containing La and an intermetallic compound phase containing Ce in a 200 μm x 200 μm visual field of a surface structure of the plated layer in a plan view is 1 or more.

[0015] [4] The steel plated material according to any of [1] to [3], where Petition 870250088824, dated 09 / 30 / 2025, page 14 / 53 / 38 a total of one or two La and Ce in the plated layer is 0.050 to 0.500%, and a number of one or more of an intermetallic compound phase containing LaCe, an intermetallic compound phase containing La and an intermetallic compound phase containing Ce in a 200 μm x 200 μm visual field of a surface structure of the plated layer in a plan view is 3 or more.

[0016] [5] The steel plated material according to any of [1] to [4], wherein a fraction of the area of ​​the [α / MgZn eutectic structure] contained in a surface structure of the plated layer in a plan view is 5 to 70%.

[0017] [6] The steel plated material according to any one of claims 5 from [1] to [5], wherein a diffraction intensity of the plated layer obtained from an X-ray diffraction measurement result satisfies formula (2) below: 0.25 < I(100)zn / {I(002)zn + I(101)zn + I(100)zn} < 3.00 ··· (2).

[0018] [7] The steel plated material according to any of [1] to [6], where The Sn content in the plated layer is 0.05 to 0.50% by mass, and an Mg2Sn phase is detected by the X-ray diffraction measurement of the plated layer. Advantageous Effects of the Invention

[0019] According to the present invention, it is possible to provide a plated steel material having exceptional resistance to red rust and resistance to corrosion of base metals. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] [Figure 1] A schematic cross-sectional view of a steel plated material according to an embodiment of the present Petition 870250088824, dated 09 / 30 / 2025, page 15 / 53 / 38 invention. DESCRIPTION OF THE MODALITIES

[0021] The sacrificial corrosion resistance of a plated layer is obtained by forming a plated layer containing an element (e.g., Zn, Mg, and the like) having a higher ionization tendency than the base metal on the surface of a steel material and corroding the plated layer preferentially in relation to the base metal.

[0022] Therefore, the present inventors conducted intensive studies to improve the sacrificial corrosion resistance of a Zn-plated layer containing Al and Mg. An η-Zn phase contained in the plated layer has a hexagonal crystal structure, and several crystal orientation planes are included within it. The corrosion resistance of these crystal orientation planes is not uniform across all orientation planes. For example, since the (002) plane of the η-Zn phase is a dense crystal orientation plane in which the atomic density of Zn is relatively high, Zn itself is considered not to dissolve easily, and the corrosion resistance of Zn itself is relatively high.On the other hand, since the (100) plane of the η-Zn phase is a crystalline orientation plane in which the atomic density of Zn is lower than that of the (002) plane, Zn itself dissolves relatively easily, and the corrosion resistance of Zn itself is low, but the corrosion of base metals is protected by a corrosion product generated along with the corrosion of Zn, and therefore the sacrificial corrosion resistance relative to the base metal is considered to be high. Therefore, it was considered that the sacrificial corrosion resistance, specifically the red rust resistance and the corrosion resistance of base metals, of the Zn-plated layer containing Al and Mg, can be improved by orienting the (100) plane of the η-Zn phase parallel to the surface of the plated layer.

[0023] Therefore, the present inventors attempted to guide the plan Petition 870250088824, dated 09 / 30 / 2025, page 16 / 53 / 38 (100) of the η-Zn phase contained in the plated layer parallel to the surface of the plated layer. When the Zn plated layer containing Al and Mg is solidified from a molten state, an α phase crystallizes first, then an MgZn2 phase or an η-Zn phase crystallizes and, in addition, a ternary eutectic structure including the α phase, the MgZn2 phase and the η-Zn phase is generated. It was verified that, when a dendritic α phase crystallizes a lot at this time, the ternary eutectic structure, including the η-Zn phase, is oriented in a random direction.Therefore, it was verified that when the surface of a steel material is roughened, one or both of La and Ce are incorporated into a plating layer and, furthermore, the cooling conditions are controlled, the crystallization of an α phase is suppressed, and the crystallization of a ternary eutectic structure proceeds from the vicinity of the interface between the plating layer and the base metal as a starting point, and, as a result, the (100) plane of an η-Zn phase contained in the ternary eutectic structure is oriented to be parallel to the surface of the plating layer.

[0024] Hereafter, plated steel material according to an embodiment of the present invention will be described. A clad steel material of the present embodiment comprises a steel material and a clad layer disposed over a surface of the steel material, the clad layer having a chemical composition containing, in terms of % by mass, Al: 6.0 to 30.0%, Mg: 3.0 to 15.0%, Fe: 0.01 to 15.00%, Si: 0 to 2.0%, and Ca: 0 to 2.00%, containing one or two of La and Ce: 0.005 to 0.500% in total and containing one or two or more elements selected from the group of elements 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%, Ni: 0 to 1.000%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, B: 0 to 0.500%, 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 0.50%, V: 0 to 0.500% and W: 0 to 0.50%, in a total quantity of 0 to 5.0%, and the Petition 870250088824, dated 09 / 30 / 2025, page 17 / 53 / 38 remaining: Zn is an impurity, and the plated layer has a diffraction intensity obtained from an X-ray diffraction measurement result, the diffraction intensity satisfying the following formula (1). The steel material surface mentioned here refers to the interface between the plated layer and the steel material. 0.15 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} < 3.00 ••• (1)

[0025] In formula (1), I(100)Zn represents the diffraction intensity of a plane of the η-Zn (100) phase, I(002)Zn represents the diffraction intensity of a plane of the η-Zn (002) phase, I(101)Zn represents the diffraction intensity of a plane of the η-Zn (101) phase, and I(100)Zn represents the diffraction intensity of a plane of the η-Zn (100) phase.

[0026] In the following description, the expression “%” of the content of each element in a chemical composition means “% by mass”. The content of an element in the chemical composition may be referred to as an element concentration (e.g., Zn concentration, Mg concentration, and the like). “Red rust resistance” indicates a property of suppressing the generation of red rust in a steel material in a portion where the steel material is exposed (e.g., a portion of the end surface where the plated steel material is cut, a portion where the plated layer is cracked due to processing, and a portion where the steel material is exposed due to peeling of the plated layer). “Base metal corrosion resistance” indicates a property of suppressing the increase in corrosion depth when a steel material corrodes in the portion where the steel material is exposed.The term "corrosion resistance of flat portions" indicates a property of the plating layer (specifically, the Zn-Al-Mg alloy layer) that is less likely to corrode. "Plating layer" refers to a plating film manufactured by a process called hot-dip galvanizing.

[0027] As illustrated in Figure 1, a sheeted steel material Petition 870250088824, dated 09 / 30 / 2025, page 18 / 53 / 38, according to the present embodiment, includes a steel material 11. The shape of the steel material 11 is not particularly limited, and an example of steel material 11 is a steel sheet. Furthermore, the steel material 11 may be, for example, a formed base steel material, such as a steel pipe, a civil engineering and construction material (fence manhole, corrugated pipe, drainage channel cover, splash prevention plate, screw, wire mesh, guardrail, water retaining wall and the like), a household appliance member (an outdoor unit casing of an air conditioner or the like) and a vehicle component (a suspension member or the like). Forming is, for example, various deformation processing methods, such as pressing, roll forming and bending.

[0028] The material of steel 11 is not particularly limited. The material of steel 11 may be, for example, various steel materials, such as general steel, Al-killed steel, ultra-low carbon steel, high carbon steel, various high tensile strength steels and some high alloy steels (a steel containing a reinforcing element, such as Ni, Cr, etc.). The material of steel 11 may be a hot-rolled steel sheet, a hot-rolled steel strip, a cold-rolled steel plate, a cold-rolled steel strip and the like described in JIS G 3302: 2010. The manufacturing method of the steel sheet (hot rolling method, pickling method, cold rolling method or the like), the specific manufacturing conditions thereof and the like are also not particularly limited.

[0029] Steel material 11, which serves as an original plating sheet, may be a pre-plated steel material, pre-plated onto the surface of steel material 11. An example of pre-plated steel material is a pre-plated Ni steel material having a Ni plating on the steel material 11. Pre-plated steel material is obtained by Petition 870250088824, dated 09 / 30 / 2025, page 19 / 53 / 38 example, by electrolytic treatment or displacement plating. Electrolytic treatment is carried out by immersing a base steel material in a sulfuric acid bath or a chloride bath containing metallic ions of various pre-plating compositions to perform an electrolytic treatment. Displacement plating is carried out by immersing a base steel material in an aqueous solution containing metallic ions of various pre-plating compositions and having a pH adjusted with sulfuric acid to replace and deposit the metal.

[0030] The clad steel material 1 according to the present embodiment includes a clad layer 12 in the steel material 11. In the clad steel material 1 according to the present embodiment, the clad layer 12 is mainly made of a Zn-Al-Mg alloy layer due to the chemical composition described below. Furthermore, the clad layer 12 of the clad steel material 1 according to the present embodiment may include an Fe-Al based interfacial alloy layer between the steel material 11 and the Zn-Al-Mg alloy layer. That is, the clad layer 12 may have a single-layer structure of the ZnAl-Mg alloy layer or a laminated structure including the Zn-Al-Mg alloy layer and the Fe-Al based interfacial alloy layer. In addition, the Fe-Al based interfacial alloy layer may contain Ni.

[0031] The plating layer according to the present embodiment is made, as the chemical composition, of Zn and other alloying elements. The chemical composition of the plating layer will be described in detail below. Note that the elements whose concentration has a lower limit of 0% are not essential to solve the problem of the plating steel material according to the present embodiment, but are optional elements that can be included in the plating layer for the purpose of, for example, improving the characteristics. <Al: 6,0 a 30,0%> Petition 870250088824, dated 09 / 30 / 2025, page 20 / 53 / 38

[0032] Al forms an α phase which is a solid solution with Zn and contributes to improved corrosion resistance of flat portions, sacrificial corrosion resistance, and workability. Therefore, the Al concentration is defined as 6.0% or more. The Al concentration can be defined as 10.0% or more, 12.0% or more, or 15.0% or more. On the other hand, when there is an excess of Al, the Mg concentration and the Zn concentration decrease relatively, and the red rust resistance and base metal corrosion resistance deteriorate. Therefore, the Al concentration is defined as 30.0% or less. The Al concentration can be defined as 28.0% or less, 25.0% or less, or 20.0% or less. <Mg: 3,0 a 15,0%>

[0033] Mg is an essential element to ensure corrosion resistance of flat surfaces, resistance to red rust, and corrosion resistance of base metals. Therefore, the Mg concentration is defined as 3.0% or less. The Mg concentration can be defined as 4.5% or more or 6.0% or more. On the other hand, when the Mg concentration is excessive, workability, particularly spray properties, can deteriorate, and corrosion resistance of flat surfaces can deteriorate even further. Therefore, the Mg concentration is defined as 15.0% or less. The Mg concentration can be defined as 12.0% or less, 10.0% or less, or 8.0% or less. <Fe: 0,01% a 15,00%>

[0034] Iron (Fe) may be contained in the plating layer in an amount of 0.01% or more. It has been confirmed that when the Fe concentration is 15.00% or less, the performance of the plating layer is not adversely affected. The Fe concentration can be defined as, for example, 0.05% or more, 0.10% or more, 0.50% or more, or 1.00% or more. The Fe concentration can be defined as, for example, 10.00% or less, 5.00% or less, 2.00% or less, or 1.00% or less. As the Fe Petition 870250088824, dated 09 / 30 / 2025, page 21 / 53 / 38, can be mixed with steel material, the Fe concentration can be 0.05% or more. <Si: 0% a 2,0%>

[0035] The Si concentration can be 0%. On the other hand, Si contributes to improving the corrosion resistance of flat portions. Therefore, the Si concentration can be defined as 0.05% or more, 0.1% or more, 0.2% or more, or 0.5% or more. Conversely, when the Si concentration is excessive, the corrosion resistance of flat portions, the resistance to red rust, and the corrosion resistance of base metals deteriorate. Therefore, the Si concentration is defined as 2.0% or less. The Si concentration can be defined as 1.5% or less, 1.0% or less, or 0.5% or less. <Ca: 0% a 2,00%>

[0036] The concentration of Ca can be 0%. On the other hand, Ca is an element capable of adjusting the ideal amount of Mg elution to confer corrosion resistance to flat portions. Therefore, the concentration of Ca can be 0.05% or more, 0.10% or more, or 0.50% or more. Conversely, when the concentration of Ca is excessive, the corrosion resistance of flat portions and workability deteriorate. Therefore, the concentration of Ca is defined as 2.00% or less. The concentration of Ca can be defined as 1.00% or less, 0.50% or less, or 0.10% or less. <Total de um ou dois de La e Ce: 0,005 a 0,500%>

[0037] Either or both of La and Ce are contained in the plating layer and therefore contribute to improving red rust resistance and base metal corrosion resistance. When the total La and Ce is less than 0.005%, red rust resistance and base metal corrosion resistance cannot be improved. Furthermore, when the total La and Ce exceeds 0.500%, the corrosion resistance of flat portions deteriorates. Therefore, the total of one or two La and Ce is defined as 0.005 to 0.500%. The total La and Ce can be 0.008% or more, 0.010% or more, or Petition 870250088824, dated 09 / 30 / 2025, page 22 / 53 / 38 0.050% or more. In addition, the total La and Ce content can be 0.200% or less or 0.100% or less. When La and Ce are present, the crystallization of the α phase is suppressed when the plated layer solidifies, making it easy for the (100) plane of the η-Zn phase, which is present in large quantities in the ternary eutectic structure, to be oriented parallel to the surface of the plated layer. Therefore, the red rust resistance and corrosion resistance of base metals are considered to improve.

[0038] In addition, the plating layer according to the present embodiment may contain one or two or more elements selected from the group of elements: 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%, Ni: 0 to 1.000%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, B: 0 to 0.500%, 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 0.50%, V: 0 to 0.500%, and W: 0 to 0.50%. The sum of these elements is 0 to 5.0%. When the total exceeds 5.0%, the corrosion resistance of flat portions, the resistance to red rust, and the corrosion resistance of base metals may deteriorate. Furthermore, these elements are optional additive elements, and the total quantity may be 0%. <Sb, Pb: 0 a 0,50% cada>

[0039] The concentration of Sb and Pb can be 0%. On the other hand, Sb and Pb contribute to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of each of Sb and Pb can be defined as 0.05% or more, 0.10% or more, or 0.15% or more. On the other hand, when the concentration of Sb and Pb is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of each of Sb and Pb is defined as 0.50% or less. The concentration of each of Sb and Pb can be defined as 0.40% or less, 0.30% or less, or 0.25% or less. <Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag e Li: 0 a 1,00% cada> Petition 870250088824, dated 09 / 30 / 2025, page 23 / 53 / 38

[0040] The concentration of each of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag, and Li can be 0%. On the other hand, they contribute to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of each of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag, and Li can be defined as 0.05% or more, 0.08% or more, or 0.10% or more. On the other hand, when the concentration of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag, and Li is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of each of Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag, and Li is defined as 1.00% or less. The concentration of each of the following elements: Cu, Ti, Cr, Nb, Zr, Mn, Mo, Ag, and Li can be defined as 0.80% or less, 0.70% or less, or 0.60% or less. <Ni: 0 a 1,000%>

[0041] The concentration of Ni can be, each, 0%. On the other hand, they contribute to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of Ni can be defined as 0.050% or more, 0.080% or more, or 0.100% or more. On the other hand, when the concentration of Ni is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of Ni is defined as 1.000% or less. The concentration of Ni can be defined as 0.800% or less, 0.700% or less, or 0.600% or less. <Sn: 0 a 1,00%>

[0042] The concentration of Sn can be 0%. On the other hand, Sn is an element that forms an intermetallic compound with Mg and improves the resistance to red rust and the corrosion resistance of base metals in the plating layer. Therefore, the concentration of Sn can be defined as 0.01% or more, 0.05% or more, or 0.10% or more. However, when the concentration of Sn is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of Sn is defined as 1.00% or less. The concentration of Sn can be defined as 0.50% or less, 0.30% or Petition 870250088824, dated 09 / 30 / 2025, page 24 / 53 / 38 less or 0.20% or less. <B: 0 a 0,500%>

[0043] The concentration of B can be 0%. On the other hand, B contributes to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of B can be defined, each, as 0.100% or more, 0.150% or more, or 0.200% or more. On the other hand, when the concentration of B is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of B is, each, 0.500% or less. The concentration of B can be defined, each, as 0.400% or less or 0.300% or less. <Y, P e Sr: 0 a 0,50% cada>

[0044] The concentration of each of Y, P, and Sr can be 0%. On the other hand, Y, P, and Sr contribute to improving red rust resistance and corrosion resistance of base metals. Therefore, the concentration of each of Y, P, and Sr can be defined as 0.10% or more, 0.15% or more, or 0.20% or more. Conversely, when the concentration of Y, P, and Sr is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of each of B, Y, P, and Sr is defined as 0.50% or less. The concentration of each of Y, P, and Sr can be defined as 0.40% or less or 0.30% or less. <Co, Bi e V: 0 a 0,500% cada>

[0045] The concentration of each of Co, Bi, and V can be 0%. On the other hand, Co, Bi, and V contribute to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of each of Co, Bi, and V can be defined as 0.100% or more, 0.150% or more, or 0.200% or more, respectively. Conversely, when the concentration of Co, Bi, and V is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of each of Co, Bi, and V is defined as 0.500% or less. The concentration of each of Co, Bi, and Petition 870250088824, dated 09 / 30 / 2025, page 25 / 53 / 38 V can be defined as 0.400% or less, or 0.300% or less. <In e W: 0 a 0,50% cada>

[0046] The concentration of each of In and W can be 0%. On the other hand, In and W contribute to improving the resistance to red rust and the corrosion resistance of base metals. Therefore, the concentration of each of In and W can be defined as 0.10% or more, 0.15% or more, or 0.20% or more, respectively. On the other hand, when the concentration of In and W is excessive, the corrosion resistance of flat portions deteriorates. Therefore, the concentration of each of In and W is defined as 0.50% or less. The concentrations of In and W can be defined as 0.40% or less and 0.30% or less, respectively. <Restante: Zn e impurezas>

[0047] The remainder of the plating layer components according to the present embodiment includes Zn and an impurity. Zn is an element that imparts corrosion resistance to flat portions, resistance to red rust, and corrosion resistance to base metals to the plating layer. In the present embodiment, the impurity means a mixed impurity from a manufacturing environment or similar and an impurity permitted to a point where the characteristics of the plating steel material according to the present embodiment are not adversely affected. For example, in the plating layer, a small amount of components other than Fe may be mixed as the impurity due to mutual atomic diffusion between the base steel material and the plating bath.

[0048] The chemical components of the plating layer are measured by the following method. For example, the plating material is cut to a size of 30 mm x 30 mm to obtain a measurement sample. Then, an acidic solution is obtained by removing and dissolving the plating layer in the measurement sample using a 10% aqueous solution of hydrochloric acid to which 0.06% by mass of an inhibitor has been added. Petition 870250088824, dated 09 / 30 / 2025, page 26 / 53 / 38 (manufactured by ASAHI Chemical Co., Ltd., IBIT 710K) to suppress corrosion of steel material. The resulting acid solution is then subjected to ICP analysis. In this way, the chemical composition of the plating layer can be determined. When cutting plating steel material, it is preferable to avoid the end portion and the weld of the plating material. The type of acid is not particularly limited, as long as the acid can dissolve the plating layer. For example, the acid is 10% by vol. HCl. The chemical composition is measured three times by the means described above, and the average of these is taken as the chemical composition of the plating layer.

[0049] A metallographic structure of the clad layer will be described next.

[0050] The plating layer contains an α phase and a MgZn2 phase. The α phase is a phase containing a fine Al phase and a fine Zn phase. Part of the α phase and the MgZn2 phase can form a lamellar binary eutectic structure ([α / MgZn2 phase eutectic structure]). When the [α / MgZn2 phase eutectic structure] is present, the corrosion resistance of flat portions of the plating layer improves further. However, when the plating layer contains a large amount of [α / MgZn2 phase eutectic structure] due to excessive precipitation of the α phase and the MgZn2 phase, the proportion of the η-Zn phase becomes relatively small, and the red rust resistance and corrosion resistance of the base metal deteriorate. Therefore, [the eutectic structure of the α / MgZn2 phase] can be in the range of 70% or less, in the range of 5 to 70%, or in the range of 10 to 70% in terms of area fraction. The [eutectic structure of the α / MgZn2 phase] can be 0% or more than 0%.

[0051] Furthermore, the plated layer of the present embodiment contains an η-Zn phase in addition to the α phase and the MgZn2 phase. At least part of the η-Zn phase forms a ternary eutectic structure together with the α phase and the MgZn2 phase. In addition, the η-Zn phase may be contained in the plated layer as a massive η-Zn phase. Petition 870250088824, dated 09 / 30 / 2025, page 27 / 53 / 38

[0052] Furthermore, when 0.05 to 0.5% of Sn is contained in the plating layer, the Mg2Sn phase is reliably contained in the plating layer. The Mg2Sn phase may be present even when the amount of Sn is 0.05% or less. Because the amount of Mg2Sn phase is small, its presence is confirmed by X-ray diffraction measurement. When the plating layer contains the Mg2Sn phase, the plating steel material has greater resistance to red rust.

[0053] When a peak is detected at 23.4 ± 0.3° in the Ka-ray X-ray diffraction measurement from a Cu tube, it is determined that the Mg2Sn phase is present. The X-ray diffraction measurement is performed using an X-ray diffractometer (manufactured by Rigaku Corporation (model number RINT-TTR III)) under the following conditions: X-ray output: 50 kV and 300 mA; copper target; TTR goniometer (horizontal goniometer); filter slit width Ke: 0.05 mm; longitudinal boundary slit width: 2 mm; light receiving slit width: 8 mm; and light receiving slit 2: open, and under the following measurement conditions: scan speed: 5 degrees / min., step width: 0.01 degrees, and geometric scan axis: 2Θ (5 to 90°).

[0054] In addition, the plated layer may contain one or more phases of LaCe-containing intermetallic compound, one phase of La-containing intermetallic compound and one phase of Ce-containing intermetallic compound, as described later.

[0055] The plated layer may contain a phase different from the phases described above as remaining. For example, an Al-Ca-Si phase or similar may be contained.

[0056] The crystal orientation of the η-Zn phase will be described next.

[0057] In the plated layer of the present embodiment, the X-ray diffraction intensity obtained from the result of the X-ray diffraction measurement of the plated layer must satisfy the relationship of the following formula. Petition 870250088824, dated 09 / 30 / 2025, page 28 / 53 / 38 (1). When the following formula (1) is satisfied, the (100) plane of the η-Zn phase is oriented to become parallel to the surface of the plating layer, and the resistance to red rust and the corrosion resistance of base metals improve. The X-ray diffraction intensity more preferably satisfies the following formula (2). When I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} is less than 0.15, the orientation of the (100) plane of the η-Zn phase is not sufficient, and the resistance to red rust and the corrosion resistance of base metals become insufficient. Furthermore, when I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} exceeds 3.00, there is a concern that the corrosion resistance of flat portions may deteriorate. 0.15 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)zo} < 3.00 ••• (1) 0.25 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} < 3.00 ••• (2)

[0058] In formula (1) and formula (2), I(100)Zn represents the diffraction intensity of a plane of the η-Zn (100) phase, I(002)Zn represents the diffraction intensity of a plane of the η-Zn (002) phase, I(101)Zn represents the diffraction intensity of a plane of the η-Zn (101) phase, and I(100)Zn represents the diffraction intensity of a plane of the η-Zn (100) phase.

[0059] Furthermore, when the total of one or two La and Ce in the plated layer is 0.01 to 0.50%, one or more of the total LaCe-containing intermetallic compound phase, the La-containing intermetallic compound phase, and the Ce-containing intermetallic compound phase are preferably contained within a 200 μm x 200 μm field of view of the surface structure of the plated layer in a plan view. More preferably, 3 or more of one or more of these intermetallic compound phases are contained within the 200 μm x 200 μm field of view. 10 or fewer of any one or more of the intermetallic compound phases are preferably contained within the 200 μm x 200 μm field of view.

[0060] The LaCe-containing intermetallic compound phase is a La and Ce-containing intermetallic compound phase, the compound phase Petition 870250088824, dated 09 / 30 / 2025, page 29 / 53 / 38 An intermetallic compound containing La is a phase of the intermetallic compound containing La, and the phase of the intermetallic compound containing Ce is a phase of the intermetallic compound containing Ce. Examples of elements other than La and Ce contained in these intermetallic compound phases include Al, Ca, Si, Mg, and Zn. For example, as such intermetallic compound phases, an AlCa-Si-Mg-Zn-(La, Ce) phase, a Ca-Zn-(La, Ce) phase, and the like may be contained. The notation (La, Ce) means one or both La and Ce. When such an intermetallic compound phase is contained, the (100) plane of the η-Zn phase is strongly oriented to become parallel to the surface of the plating layer, and the red rust resistance and base metal corrosion resistance are further improved.

[0061] One method for measuring the area fraction of the [eutectic structure of the α / MgZn2 phase] is as follows. First, the surface of the plated layer is adjusted to be flat by mechanical polishing. Then, the surface of the plated layer is chemically polished by colloidal polishing, and polishing is continued until the surface becomes a mirror-like state.

[0062] The surface of the plated layer after polishing is observed by SEM. Specifically, an element distribution image is captured using SEM-EDS at a magnification of 5000 times (a region 200 μm long and 200 μm wide). In this element distribution image, a phase in which Mg and Zn coexist is specified as the MgZn2 phase. Additionally, a phase containing Al and Zn is specified as the α phase. Most of the α phase exhibits a dendritic shape. Furthermore, after the [eutectic structure of the α / MgZn2 phase] containing the α phase and the MgZn2 phase is specified, the area fraction of the [eutectic structure of the α / MgZn2 phase] contained in the visual field is calculated by binarization using image analysis software.

[0063] A method for measuring Ι(100)ζπ / {Ι(002)ζπ + I(101)zn + Petition 870250088824, dated 09 / 30 / 2025, page 30 / 53 / 38 I(100)zn} in formula (1) and in formula (2) is as follows. First, the surface of the plated layer is mechanically and chemically polished, as needed, to bring the surface of the plated layer to a mirror-like surface state. Then, for example, X-ray diffraction measurement is performed using an X-ray diffractometer (manufactured by Rigaku Corporation (model number RINT-TTR III) under the following conditions: X-ray output: 50 kV and 300 mA; copper target; TTR goniometer (horizontal goniometer); filter slit width Ke: 0.05 mm; longitudinal boundary slit width: 2 mm; light receiving slit width: 8 mm; and light receiving slit 2: open, and under the following measurement conditions: scan speed: 5 degrees / min., step width: 0.01 degrees, and geometric scan axis: 2Θ (5 to 90°).Next, for the η-Zn phase, the diffraction intensity (maximum intensity in the range of 38.993 ± 0.2°) of the (100) plane, the diffraction intensity (maximum intensity in the range of 36.297 ± 0.2°) of the (002) plane, and the diffraction intensity (maximum intensity in the range of 43.232 ± 0.2°) of the (101) plane are measured. The diffraction intensity excludes the background intensity. From the obtained diffraction intensity, I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} is determined.

[0064] The presence or absence of the Mg2Sn phase in the plated layer is determined by the appearance or not of a specific diffraction peak for Mg2Sn when X-ray diffraction measurement is performed.

[0065] Furthermore, a method for measuring the LaCe-containing intermetallic compound phase numbers, La-containing intermetallic compound phase numbers, and Ce-containing intermetallic compound phase numbers in the surface layer structure of the plated layer is as follows. First, the surface of the plated layer is mechanically and chemically polished, as needed, to bring the surface of the plated layer to a mirror-like surface state. Then, a rectangular visual observation field 200 μm long and 200 μm wide is placed on the surface of the Petition 870250088824, dated 09 / 30 / 2025, page 31 / 53 / 38 plated layer. An element distribution image is captured using SEM-EDS in this observed visual field. In this element distribution image, a phase containing one or both La and Ce is specified as any of the phases of the LaCe-containing intermetallic compound, the La-containing intermetallic compound phase, and the Ce-containing intermetallic compound phase. Furthermore, the numbers of these intermetallic compounds are counted.

[0066] The amount of adhesion of the plating layer per surface can be, for example, within a range of 20 to 300 g / m2. When the amount of adhesion per surface is defined as 20 g / m2 or more, the corrosion resistance of flat portions, the resistance to red rust, and the corrosion resistance of base metals of the plating steel material can be further improved. On the other hand, when the amount of adhesion per surface is defined as 300 g / m2 or less, the workability of the plating steel material can be further improved.

[0067] The method for producing a sheeted steel material according to the present embodiment will be described below, but the method for producing a sheeted steel material according to the present embodiment is not particularly limited. For example, according to the manufacturing conditions described below, the sheeted steel material according to the present embodiment can be obtained.

[0068] In a method of manufacturing the plating steel material of the present embodiment, a steel material having irregularities formed on the surface is used as an original plating sheet. This steel material is annealed in a reducing atmosphere, and the steel material immediately after annealing is immersed in a hot-dip plating bath and then pulled up to form a plating layer on the surface of the steel material. The plating layer is then cooled at an average cooling rate of 15°C / s or more until the temperature of Petition 870250088824, dated 09 / 30 / 2025, page 32 / 53 / 38 plated layer reaches 340°C from the bath temperature and then cooled at an average cooling rate of 7°C / s or less in a range of 340 to 320°C, while a cooling gas is sprayed at a flow rate of 15000 (L / min / m2) or higher.

[0069] For the surface roughness of the steel material serving as the original plating sheet, the ratio (Lp / L0) of the curve length Lp of the roughness curve to the reference length L0 is defined as 1.08 or more. When the surface roughness (Lp / L0) of the steel material is defined as 1.08 or more, nucleation sites for crystallizing the ternary eutectic structure are formed near the interface between the plating layer and the steel sheet. The upper limit of (Lp / L0) is preferably 3.00 or less and may be 2.50 or less. The reference length L0 is the length of the plating layer in the longitudinal direction in a cross-sectional view, and the curve length Lp is the curve length of a roughness curve relative to the reference length L0 in a cross-sectional view of the plating layer, i.e., the total length of the surface profile of the plating layer.

[0070] The method for adjusting the surface roughness of steel material is not particularly limited, but the roughness can be adjusted, for example, by rolling the original sheet with a rolling mill roll or a roll for tempering rolling, the roll surface of which has been adjusted to a desired roughness to transfer the shape of the roll surface. Alternatively, the roughness can be adjusted by pickling.

[0071] The (Lp / L0) measurement is measured using, for example, a 3D laser microscope (model number: VK-8700), which is manufactured by KEYENCE CORPORATION. The measurement is performed, for example, under the following conditions: scanning area: 200 μm x 200 μm, measurement mode: confocal laser, measurement quality: high precision, step: 0.75 μm, Petition 870250088824, dated 09 / 30 / 2025, page 33 / 53 / 38 double scan: ON, optical zoom: 1 time, objective lens name: Plano, coefficient γ: 0.45 and displacement: 0%. The measuring device used to measure (Lp / L0) is not limited to the example above.

[0072] The steel material that serves as the original plating sheet is annealed in a reducing atmosphere. The reducing atmosphere and annealing conditions are not particularly restrictive. With this annealing, the oxide present on the surface of the steel material is removed as much as possible.

[0073] Subsequently, the steel material immediately after annealing is immersed in a hot-dip plating bath. The chemical composition of the hot-dip plating bath can be adjusted appropriately to obtain the chemical composition of the plating layer described above. The temperature of the hot-dip plating bath is also not particularly limited. It is possible to appropriately select a temperature at which hot-dip plating can be performed. For example, the plating bath temperature can be set above the melting point of the plating bath by about 20°C or more.

[0074] Next, the steel material is removed from the hot-dip plating bath. The amount of adhesion of the plating layer can be controlled by controlling the pulling speed of the steel material. If necessary, the steel material to which the plating layer is adhered can be cleaned to control the amount of adhesion of the plating layer. The amount of adhesion of the plating layer is not particularly limited and may be, for example, within the range described above.

[0075] Next, the plating layer is cooled. Regarding cooling, the plating layer is first cooled at an average cooling rate of 15°C / s or more until the temperature of the plating layer Petition 870250088824, dated 09 / 30 / 2025, p. 34 / 53 / 38 reach 340°C from the bath temperature. The average cooling rate until the plating layer temperature reaches 340°C from the bath temperature can be 30°C / s or less. Cooling can be achieved, for example, by spraying a cooling gas. When the cooling gas is sprayed for cooling, a plurality of blow nozzles for the cooling gas can be arranged along the transport path of the steel material, and the cooling gas can be sprayed through the nozzles. When the plating layer is cooled at 15°C / s or more in a bath temperature range up to 340°C, the generation of the α dendritic phase, which is generated in the initial phase of the solidification stage, is suppressed.Since α-phase dendrites can serve as nucleation sites during the crystallization of the ternary eutectic structure, when α-phase generation is suppressed, a ternary eutectic structure is formed from nucleation sites near the interface between the steel material and the plating layer.

[0076] Subsequently, the clad layer is cooled in a range of 340 to 320°C at an average cooling rate of 7°C / s or less, while a cooling gas is sprayed at a flow rate of 15000 (L / min / m2) or higher. At this point, the clad layer can be cooled at an average cooling rate of 2°C or more. Furthermore, the cooling gas flow rate during cooling can be 25000 (L / min / m2) or lower. Also in this case, a plurality of blow nozzles for the cooling gas is arranged along the transport path of the steel material. Additionally, when the flow rate is set to 15000 (L / min / m2) or higher, the clad layer is vibrated by the spray of the cooling gas, while the clad layer is not overcooled. As a result, the crystallization of a ternary eutectic structure is initiated from the proximity of the interface between the plating layer and the steel material as a starting point, and the eutectic structure Petition 870250088824, dated 09 / 30 / 2025, page 35 / 53 / 38 ternary growth towards the surface of the plated layer.

[0077] The cooling gas to be sprayed is not particularly limited and may be a non-oxidizing gas, such as nitrogen, an inert gas, such as argon or air, or a mixture of the same.

[0078] When the cooling gas flow is controlled, the shape of the gas nozzle from which the cooling gas is expelled is adjusted, for example, in a diameter range of 1 to 50 mm. The angle formed by the tip of the gas nozzle and the steel plate is adjusted, for example, in a range of 70 to 110°, more preferably 90° (perpendicular). The distance between the tip of the gas nozzle and the steel plate is defined in a range of 30 to 1000 mm. The shape, angle and distance of the gas nozzle are merely examples, and are not limited to the ranges above.

[0079] There is no need to particularly limit the cooling condition below 320°C, and the cooling can be air or natural.

[0080] When the plated layer is cooled to satisfy the above conditions, a plated layer that satisfies formula (1) is formed. The ratio is assumed as follows.

[0081] In the above manufacturing method, an irregularity is provided on the surface of the steel material prior to hot-dip plating, whereby the nucleation sites of the ternary eutectic structure are formed in the vicinity of the interface between the steel material and the plated layer. Furthermore, the steel material immersed in a plating bath is cooled under the above conditions by being pulled upwards, so that the nucleation sites that serve as a starting point for the crystallization of the ternary eutectic structure are formed not in the α-phase dendrites, but near the interface between the steel material and the plated layer. In the ternary eutectic structure crystallized from the vicinity of the interface between the steel material and the plated layer as a starting point, the orientations of the crystals are oriented in a constant direction, Petition 870250088824, dated 09 / 30 / 2025, p. 36 / 53 / 38, unlike a case where the α-phase dendrites are used as a starting point. As a result, the (100) plane of the η-Zn phase contained in the ternary eutectic structure is considered to be oriented to be parallel to the surface of the plated layer and Formula (1) is satisfied. Examples

[0082] Examples of the present invention will be described below. However, the conditions in the examples are merely an example of a condition adopted to confirm the operability and effects of the present invention. The present invention is not limited to this example of a condition. The present invention may adopt various conditions, provided that the object of the present invention is achieved without departing from the essence of the present invention.

[0083] As an original plating sheet, a hot-rolled steel sheet with a thickness of 1.6 mm was used. The surface roughness of the hot-rolled steel sheet was previously controlled using a cold rolling mill or similar. For surface roughness, the ratio (Lp / Lo) of the length of the roughness curve Lp to the reference length Lo was adjusted to 1.05 to 1.57.

[0084] The (Lp / Lo) measurement was taken using a 3D laser microscope (model number: VK-8700), manufactured by KEYENCE CORPORATION. Regarding the measurement conditions, the measurement was performed under the following conditions: measurement mode: confocal laser, measurement quality: high precision, step: 0.75 μm, double scan: ON, optical zoom: 1 time, objective lens name: Plano, coefficient γ: 0.45, and displacement: 0%.

[0085] Next, the original plating sheet having adjusted surface roughness was annealed. The annealing conditions were an immersion temperature of 800°C and an immersion time of 2 Petition 870250088824, dated 09 / 30 / 2025, page 37 / 53 / 38 minutes in an N2-4%H2 atmosphere. Then, the original annealed plating sheet was air-cooled with N2 gas to adjust the temperature at the time of immersion in the plating bath to approximately (plating bath temperature +20)°C, then immersed in several hot-dip plating baths and then lifted at a lifting rate of 20 to 200 mm / s. At the time of removal of the original plating sheet, the amount of plating adhesion was controlled with an N2 cleaning gas. After the steel material was removed from the plating bath, the steel material was cooled under the conditions shown in Table 2.

[0086] In cooling in the range of 340 to 320°C, a N2 gas was used as the cooling gas, and the gas flow was controlled as shown in Table 2. The shape of the gas nozzle, from which the cooling gas was expelled, had a diameter of 6 mm, the angle formed by the tip of the gas nozzle and the steel plate was perpendicular, and the distance between the tip of the gas nozzle and the steel plate was 35 mm.

[0087] In this way, the steel plated materials from No. 1 to 47 were manufactured.

[0088] The chemical composition of the plating layer was shown in Table 1. In addition, the metallographic structure of the plating layer was evaluated, and the results are shown in Table 3. Furthermore, the red rust resistance and base metal corrosion resistance of the plating steel material were evaluated, and the results are shown in Table 4.

[0089] The chemical composition of the plated layer was measured by immersing a sample cut to a size of 30 mm x 30 mm in a 10% aqueous HCl solution to which an inhibitor was added for pickling and removal of the plated layer, and ICP analysis was then performed on elements eluted in the aqueous solution.

[0090] The area fraction of the [eutectic structure of the α / MgZn2 phase] was Petition 870250088824, dated 09 / 30 / 2025, page 38 / 53 / 38 evaluated as follows. First, the surface of the plated layer was polished by mechanical polishing and colloidal polishing until a mirror-like surface state was formed. Then, the surface of the plated layer was observed at a magnification of 5,000 times with a field emission scanning electron microscope (FE-SEM) equipped with an energy dispersive elemental analyzer (EDS) (a region with a length of 200 μm and a diameter of 200 μm), and an element distribution image was captured using EDS. In the element distribution image, a phase in which Mg and Zn coexisted was specified as an MgZn2 phase, a phase containing Al and Zn was specified as an α phase, and the [eutectic structure of the α / MgZn2 phase] in which these phases formed a lamellar shape was specified.Furthermore, the area fraction of the [eutectic structure of the α / MgZn2 phase] contained within the visual field was calculated by binarization using image analysis software.

[0091] A method for measuring I(100)ζπ / {I(002)ζπ + I(101)zn + I(100)Zn} in formula (1) was as follows. First, the surface of the plated layer was brought to a mirror surface state in the same manner described above. Then, the X-ray diffraction measurement was performed using an X-ray diffractometer (manufactured by Rigaku Corporation model number RINT-TTR III) under the following conditions: X-ray output: 50 kV and 300 mA; copper target; TTR goniometer (horizontal goniometer); filter slit width Ke: 0.05 mm; longitudinal boundary slit width: 2 mm; light receiving slit width: 8 mm; and light receiving slit 2: open, and under the measurement conditions of scanning speed: 5 degrees / min., step width: 0.01 degrees, and geometric scanning axis: 2Θ (5 to 90°).Next, for the η-Zn phase, the diffraction intensity (maximum intensity in the range of 38.993 ± 0.2°) of the (100) plane, the diffraction intensity (maximum intensity in the range of 36.297 ± 0.2°) of the (002) plane, and the diffraction intensity (maximum intensity in the range of... Petition 870250088824, dated 09 / 30 / 2025, page 39 / 53 / 38 43.232 ± 0.2°) of the (101) plane were measured. The diffraction intensity was an intensity that excluded the background intensity. From the diffraction intensity obtained, I(100)zn / {I(002)zn + I(101)zn + I(100)z„J was determined.

[0092] The presence or absence of the Mg2Sn phase in the plated layer was determined by the appearance or absence of a specific diffraction peak for Mg2Sn when the X-ray diffraction measurement was performed.

[0093] In addition, the numbers of a phase of the LaCe-containing intermetallic compound, a phase of the La-containing intermetallic compound, and a phase of the Ce-containing intermetallic compound in the surface layer structure of the plated layer were measured. First, the surface of the plated layer was brought to a mirror-like surface state in the same manner described above. Then, a rectangular observed visual field 200 μm long and 200 μm wide was placed on the surface of the plated layer. An element distribution image was captured using SEM-EDS in this observed visual field. In this element distribution image, a phase containing one or both La and Ce was specified as any of the LaCe-containing intermetallic compound phases, the La-containing intermetallic compound phase, and the Ce-containing intermetallic compound phase. Furthermore, the numbers of these intermetallic compounds were counted. The results are shown in Table 3.In the "LaCe-containing intermetallic compound phase" column of Table 3, the total number of LaCe-containing intermetallic compound phases, La-containing intermetallic compound phases, and Ce-containing intermetallic compound phases is shown.

[0094] Red rust resistance was evaluated as follows. The plated steel material was cut into 100 mm x 100 mm pieces to produce a test specimen. In a region centered on the intersection point of the diagonal lines of the test specimen and having a diameter of 30 mm, the plating layer was removed by milling to expose the steel sheet (metal). Petition 870250088824, dated 09 / 30 / 2025, page 40 / 53 / 38 base). The region with a diameter of 30 mm, in which the base metal was exposed, was subjected to the cyclic corrosion test specified in the JASOM609-91 method, and the red rust resistance was evaluated based on the state of red rust generation in the region in which the base metal was exposed. The evaluation criteria for red rust resistance are shown below. “AAAA”, “AAA”, “AA” and “A” were considered acceptable.

[0095] AAAA: Red rust area fraction of 2% or less in 120 cycles AAA: Red rust area fraction of more than 2% and 5% or less in 120 cycles. AA: Red rust area fraction of more than 5% and 10% or less in 120 cycles A: Fraction of red rust area of ​​more than 10% and 15% or less in 120 cycles B: Red rust area fraction of more than 15% in 120 cycles

[0096] The corrosion resistance of base metals was evaluated as follows. The plated steel material was cut into 100 mm x 100 mm pieces to produce a specimen. In a region centered on the intersection point of the specimen's diagonal lines and having a diameter of 25 mm, the plated layer was removed by milling to expose the steel sheet (base metal). The 25 mm diameter region, in which the base metal was exposed, was subjected to the cyclic corrosion test specified in JASO-M609-91, and the corrosion resistance of base metals was evaluated based on the maximum depth of corrosion of base metals in the region where the base metal was exposed. The evaluation criteria for the corrosion resistance of base metals are shown below. “AAA”, “AA”, and “A” were considered acceptable. Petition 870250088824, dated 09 / 30 / 2025, page 41 / 53 / 38

[0097] AAA: 0.5 mm or less in 360 cycles AA: 0.5 mm or less in 240 cycles A: 0.5 mm or less in 180 cycles B: More than 0.5 mm in 180 cycles

[0098] In Nos. 1 to 32 and 42 to 47 (Examples) according to the present invention, the chemical composition and metallographic structure of the plating layer were adequately controlled, and both the resistance to red rust and the resistance to corrosion of base metals were exceptional.

[0099] In Comparative Example No. 33, the amount of Al was insufficient in the plated layer. Therefore, in No. 31, the corrosion resistance of base metals was insufficient.

[00100] In Comparative Example No. 34, the amount of Al was excessive in the plated layer. Therefore, in No. 32, the α-phase dendrites were generated excessively, and the dendrites functioned as nucleation sites for the η-Zn phase, which made it impossible to guarantee the orientation of the η-Zn phase and rendered the red rust resistance and base metal corrosion resistance insufficient.

[00101] In Comparative Example No. 35, the amount of Mg was insufficient in the plated layer. Therefore, in No. 33, both the resistance to red rust and the resistance to corrosion of base metals were insufficient.

[00102] In Comparative Example No. 36, the total amount of La and Ce was insufficient in the plated layer. Therefore, in No. 36, the orientation of the η-Zn phase could not be guaranteed, and the corrosion resistance of base metals was insufficient.

[00103] In Comparative Example No. 37, the amount of Mg was excessive in the plated layer. Therefore, in No. 35, the resistance to red rust was insufficient.

[00104] In Comparative Example No. 38, the amount of gas flow Petition 870250088824, dated 09 / 30 / 2025, page 42 / 53 / 38 of the cooling gas was insufficient during cooling in the range of 340 to 320°C. Therefore, in No. 38, the orientation of the η-Zn phase could not be guaranteed, and the resistance to red rust was insufficient.

[00105] In Comparative Example No. 39, the cooling rate exceeded 7°C / s in the range of 340 to 320°C. Therefore, in Comparative Example No. 39, the orientation of the η-Zn phase could not be guaranteed, and the resistance to red rust was insufficient.

[00106] In Comparative Example No. 40, the cooling rate was less than 15°C / s in the bath temperature range up to 340°C. Therefore, in No. 40, the orientation of the η-Zn phase could not be guaranteed, and the resistance to red rust was insufficient.

[00107] In Comparative Example No. 41, the surface roughness ((Lp / Lc)) of the original plating sheet was less than 1.08. Therefore, in No. 41, the η-Zn phase orientation could not be guaranteed, and the red rust resistance was insufficient. [Table 1] Type No. Components of the plating layer (% by mass) Remaining: Zn and impurities Zn Al Mg Sn Si Ca Fe La Ce La + Ce Other elements Type Total (%) Example 1 Remaining 6.0 3.0 0 0 0 0.05 0.005 0 0.005 - Example 2 Remaining 6.0 3.0 0.06 0.1 0 0.05 0 0.005 0.005 Bi 0.005 Example 3 Remaining 10.0 3.0 0 0.1 0 0.06 0 0.005 0.005 - Example 4 Remaining 12.0 4.5 0 0.1 0.03 0.07 0.003 0.002 0.005 V 0.009 Example 5 Remaining 12.0 3.0 Example 6 Remaining 12.0 5.0 0 0.1 0.03 0.08 0.010 0 0.010 Pb 0.03 Example 7 Remaining 12.0 6.0 0 0.2 0.03 0.11 0 0.012 0.012 Zr 0.01 Example 8 Remaining 12.0 6.0 0.01 0.2 0.02 0.08 0.012 0.012 0.024 Co 0.008 Example 9 Remaining 13.0 5.0 0 0.2 0.02 0.12 0.022 0.022 0.044 Ni 0.002 Example 11 Remaining 15.0 5.0 0 0.2 0.02 0.21 0.022 0.019 0.041 Ag 0.01 Example 12 Remaining 17.0 5.0 0 0.2 0.04 0.25 0.052 0.000 0.052 Li 0.02 Example 13 Remaining 18.0 6.0 0.20 0.4 0.04 0.23 0 0.049 0.049 Sb 0.08 Example 14 Remaining 19.0 6.0 0 0.3 0.05 0.16 0.042 0.044 0.086 P 0.01 Example 15 Remaining 19.0 6.0 0 0.2 0.05 0.17 0.054 0.055 0.109 In 0.02 Example 17 Remaining 19.0 7.0 0 0.2 0.04 0.20 0 0.105 0.105 Mn 0.01 Example 18 Remaining 20.0 15.0 0 0.3 0.05 0.31 0 0.200 0.200 B 0.005 Example 19 Remaining 20.0 6.0 0.01 0.1 0.04 0.39 0.052 0.252 0.304 Sr 0.02 Example 20 Remaining 21.0 Example 21 Remaining 22.0 6.0 0 0.4 0.04 0.37 0.053 0.250 0.303 Mo 0.03 Example 22 Remaining 22.0 8.0 0 0.7 0.04 0.41 0.220 0.250 0.470 - Example 23 Remaining 22.0 4.0 0 0.1 0.01 0.32 0.002 0.005 0.007 Nb 0.02 Example 24 Remaining 24.0 3.0 0 0.1 0 0.21 0.002 0.005 0.007 -, Petition 870250088824, dated 09 / 30 / 2025, page 43 / 53 / 38 Type No. Components of the plating layer (% by mass) Remaining: Zn and impurities Zn Al Mg Sn Si Ca Fe La Ce La + Ce Other elements Type Total (%) Example 25 Remaining 22.0 4.0 0 0.1 0.01 0.44 0.002 0.005 0.007 - Example 26 Remaining 23.0 8.0 0 0.7 0.04 0.55 0.052 0.052 0.104 Ti 0.01 Example 27 Remaining 23.0 15.0 0 0.5 0.04 0.64 0.051 0.052 0.103 Y 0.01 Example 28 Remaining 25.0 8.0 0 1.1 0.04 0.60 0.053 Example 29 Remaining 24.0 7.0 0 1.5 0.04 0.71 0.052 0.052 0.104 W 0.01 Example 30 Remaining 25.0 8.0 0 2.0 0.04 1.32 0.055 0.054 0.109 - Example 31 Remaining 28.0 3.0 0.02 0.5 0.04 1.50 0.002 0.005 0.007 Cr 0.03 Example 32 Remaining 30.0 3.0 0 0.8 0.03 1.73 0.002 0.005 0.007 - Comparative Example 33 Remaining 5.0 4.0 0 0 0 0.12 0.002 0.005 0.007 - Comparative Example 34 Remaining 32.0 7.0 0 0.1 0 0.10 0.002 0.005 0.007 - Comparative Example 35 Remaining 19.0 2.0 0 0.2 0.01 0.10 0.002 0.005 0.007 - Comparative Example 36 Remaining 19.0 5.0 0 0 0.05 0.13 0 0.001 0.001 - Comparative Example 37 Remaining 19.0 16.0 0 0 0.05 0.12 0.002 0.005 0.007 - Comparative Example 38 Remaining 16.0 3.0 0 0 0.01 0.81 0.002 0.005 0.007 - Comparative Example 39 Remaining 16.0 3.0 0 0 0.01 0.06 0.002 0.005 0.007 - Comparative Example 40 Remaining 16.0 4.0 0 0 0.01 0.82 0.002 0.005 0.007 - Comparative Example 41 Remaining 22.0 3.0 0 0.4 0 0.49 0.002 0.005 0.007 - Example 42 Remaining 15.0 6.0 0 0.2 0.02 0.21 0.041 0.02 0.06 - Example 43 Remaining 19.0 6.0 0 0.2 0.03 0.22 0 0.10 0.10 - Example 44 Remaining 21.0 4.0 0 0.1 0.01 0.22 0.005 0.005 0.01 - Example 45 Remaining 19.0 7.5 0 0.1 0.04 0.39 0.050 0.25 0.30 - Example 46 Remaining 30.0 3.0 0 0 0.05 14.9 0.005 0.005 0.01 - Example 47 Remaining 25.0 15.0 0 0.3 1.00 0.06 0 0.20 0.20 B 0.005,

[00108] The underlined values ​​are outside the scope of the present invention. [Table 2' Type No. Manufacturing conditions Bath temperature (°C) Amount of adhesion of the plating layer (g / m2) Irregularity of the surface of the original sheet (Lp / L) Average cooling rate at bath temperature up to 340°C (°C / s) Average cooling rate from 340 to 320°C (°C / s) Cooling gas flow at 340 to 320°C (L / min / m2) Example 1 460 90 1.08 15 5 15000 Example 2 480 50 1.10 20 5 15000 Example 3 480 95 1.20 20 5 15000 Example 4 500 90 1.20 20 5 15000 Example 5 500 95 1.22 20 5 15000 Example 6 Example 7: 530 95 1.21 20 5 15000 Example 8: 530 98 1.20 20 5 15000 Example 9: 530 95 1.40 20 5 15000 Example 11: 530 120 1.20 20 5 15000 Petition 870250088824, dated 09 / 30 / 2025, p. 44 / 53 / 38 Type No. Manufacturing conditions Bath temperature (°C) Amount of adhesion of the plating layer (g / m2) Irregularity of the surface of the original sheet (Lp / L0) Average cooling rate at bath temperature up to 340°C (°C / s) Average cooling rate from 340 to 320°C (°C / s) Cooling gas flow at 340 to 320°C (L / min / m2) Example 12 530 88 1.57 20 5 15000 Example 13 530 78 1.26 20 5 15000 Example 14 530 87 1.20 20 5 15000 Example 15 530 95 1.22 20 5 15000 Example 17 530 90 1.24 20 5 15000 Example 18 590 98 1.40 20 5 15000 Example 19 540 78 1.42 20 5 15000 Example 20 540 250 1.25 20 5 15000 Example 21 540 89 1.43 20 5 15000 Example 22 540 88 1.40 20 5 15000 Example 23 540 95 1.08 20 5 15000 Example 24 560 180 1.20 20 5 15000 Example 25 540 95 1.26 20 5 15000 Example 26 550 90 1.27 20 5 15000 Example Example 27: 550 95 1.25 20 5 15000 Example 28: 550 89 1.23 20 5 15000 Example 29: 550 99 1.22 20 5 15000 Example 30: 550 95 1.21 20 5 15000 Example 31: 550 89 1.26 20 5 15000 Example 32: 550 95 1,Example Comparative: 28 20 5 15000 Example Comparative: 33 450 88 1.20 20 5 15000 Example Comparative: 34 600 89 1.20 20 5 15000 Example Comparative: 35 540 90 1.20 20 5 15000 Example Comparative: 36 540 91 1.20 20 5 15000 Example Comparative: 37 540 91 1.20 20 5 15000 Example Comparative: 38 520 90 1.20 20 5 13000 Example Comparative: 39 520 100 1.20 20 10 15000 Example Comparative: 40 520 100 1.20 Example 12 5 15000 Comparative Example 41 560 89 1.05 20 5 15000 Example 42 530 120 1.23 20 7 15000 Example 43 530 90 1.22 20 6 25000 Example 44 540 95 1.09 20 2 15000 Example 45 540 250 1.23 30 5 15000 Example 46 600 90 1.22 20 5 15000 Example 47 590 100 1.42 20 5 15000

[00109] The underlined values ​​are outside the scope of the preferred manufacturing conditions. Petition 870250088824, dated 09 / 30 / 2025, page 45 / 53 / 38 [Table 3] Type No. Layer XRD Surface Structure Mg2Sn Phase I(100) / (I(002) + I(101) + I(100)) LaCe-containing Compound Phase (phases) Fraction of the area of ​​the lamellar structure « / MgZrn (%) Presence and absence Example 1 0.15 0 0 Absent Example 2 0.17 0 1 Present Example 3 0.17 0 1 Absent Example 4 0.16 0 5 Absent Example 5 0.20 0 3 Absent Example 6 0.25 1 6 Absent Example 7 0.26 1 6 Absent Example 8 0.33 2 7 Present Example 9 0.40 1 9 Absent Example 11 0.39 2 9 Absent Example 12 0.39 3 10 Absent Example 13 0.44 3 12 Present Example 14 0.50 3 14 Absent Example 15 0.45 3 22 Absent Example 17 0.54 3 23 Absent Example 18 0.67 3 23 Absent Example 19 1.01 4 23 Present Example 20 1.22 4 56 Absent Example 21 1.50 5 25 Absent Example 22 3.00 7 25 Absent Example 23 0.18 0 0 Absent Example 24 0.19 0 0 Absent Example 25 0.20 0 0 Absent Example 26 0.80 3 23 Absent Example 27 0.50 3 25 Absent Example 28 0.66 4 25 Absent Example 29 0.71 3 33 Absent Example 30 0.65 3 39 Absent Example 31 0.20 0 0 Present Example 32 0.17 0 0 Absent Example Comparative 33 0.16 0 0 Absent Example Comparative 34 0.12 0 22 Absent Example Comparative 35 0.15 0 0 Absent Example Comparative 36 0.13 0 12 Absent Example Comparative 37 0.15 0 0 Absent Example Comparative 38 0.08 0 1 Absent Example Comparative 39 0.05 0 1 Absent Example Comparative 40 0.08 0 6 Absent Example Comparative 41 0.13 0 2 Absent Example 42 0.37 2 9 Absent Example 43 0.53 3 23 Absent Example 44 0.17 0 0 Absent Example 45 1.25 10 70 Absent Example 46 0.18 0 0 Absent Example 47 0.68 4 24 Absent, Petition 870250088824, dated 09 / 30 / 2025, page 46 / 53 / 38

[00110] The underlined values ​​are outside the scope of the present invention. [Table 4] Type No. Performance Resistance to red rust Corrosion depth of base metals Example 1 AA Example 2 AA A Example 3 AA A Example 4 AA AA Example 5 A AA Example 6 AA AA Example 7 AA AA Example 8 AAA AA Example 9 AA AA Example 11 AA AA Example 12 AAA AAA Example 13 AAAA AAA Example 14 AAA AAA Example 15 AAA AAA Example 17 AAA AAA Example 18 AAA AAA Example 19 AAAA AAA Example 20 AAA AAA Example 21 AAA AAA Example 22 AAA AAA Example 23 AA Example 24 AA Example 25 AA Example 26 AAA AAA Example 27 AAA AAA Example 28 AAA AAA Example 29 AAA AAA Example 30 AAA AAA Example 31 AA A Example 32 AA Example Comparative 33 AB Example Comparative 34 BB Example Comparative 35 BB Example Comparative 36 AB Example Comparative 37 BA Comparative Example 38 BA Comparative Example 39 BA Comparative Example 40 BA Comparative Example 41 BA Example 42 AAA AA Example 43 AAA AAA Example 44 AA Example 45 AAA AAA Example 46 AA Example 47 AAA AAA INDUSTRIAL APPLICABILITY

[00111] The plated steel material of the present description is Petition 870250088824, dated 09 / 30 / 2025, page 47 / 53 / 38 exceptional in terms of resistance to red rust and corrosion resistance of base metals and, therefore, is highly applicable industrially. LIST OF REFERENCE SIGNS

[00112] 1 Plated steel material Steel material Plated layer Petition 870250088824, dated 09 / 30 / 2025, pages 48 / 53

Claims

1 / 3 CLAIMS 1. Plated steel material, characterized in that it comprises: a steel material; and a plating layer on the steel material, wherein the plating layer has a chemical composition containing, in terms of % by mass, Al: 6.0 to 30.0%, Mg: 3.0 to 15.0%, Fe: 0.01 to 15.00%, Si: 0 to 2.0%, Ca: 0 to 2.00%, one or two of La and Ce: 0.005 to 0.500% in total, one or two or more elements selected from a group of elements 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%, Ni: 0 to 1.000%, Mn: 0 to 1.00%, Mo: 0 to 1.00%, Ag: 0 to 1.00%, Li: 0 to 1.00%, B: 0 to 0.500%, 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 0.50%, V: 0 to 0.500% and W: 0 to 0.50%, in a quantity of 0 to 5.0% in total, and the remainder: Zn and an impurity, and the plated layer has a diffraction intensity obtained from an X-ray diffraction measurement result,the diffraction intensity satisfying formula (1) below: 0.15 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} < 3.00 ••• (1) in formula (1), I(100)Zn represents a diffraction intensity of the η-Zn phase (100), I(002)Zn represents a diffraction intensity of the n-Zn phase (002), I(101)Zn represents a diffraction intensity of the ηZn phase (101), and I(100)Zn represents a diffraction intensity of the η-Zn phase Petition 870250088824, dated 09 / 30 / 2025, page 49 / 53 2 / 3 (100)., 2. Steel plated material according to claim 1, characterized in that Al and Mg in the plated layer are Al: 10.0 to 25.0% and Mg: 4.5 to 15.0%, respectively.

3. Steel plated material according to claim 1 or 2, characterized in that a total of one or two La and Ce in the plated layer is from 0.010 to 0.500%, and a number of one or more of an intermetallic compound phase containing LaCe, an intermetallic compound phase containing La and an intermetallic compound phase containing Ce in a 200 μm x 200 μm visual field of a surface structure of the plated layer in a plan view is 1 or more.

4. Steel plated material according to any one of claims 1 to 3, characterized in that a total of one or two La and Ce in the plated layer is from 0.050 to 0.500%, and a number of one or more of an intermetallic compound phase containing LaCe, an intermetallic compound phase containing La and an intermetallic compound phase containing Ce in a 200 μm x 200 μm visual field of a surface structure of the plated layer in a plan view is 3 or more.

5. Steel plated material according to any one of claims 1 to 4, characterized in that the area fraction of the [a / MgZn2 eutectic structure] contained in a surface structure of the plated layer in a plan view is 5 to 70%.

6. Steel plated material according to any one of claims 1 to 5, characterized in that a diffraction intensity of the plated layer obtained from a measurement result by Petition 870250088824, dated 09 / 30 / 2025, page 50 / 53 3 / 3 X-ray diffraction satisfies formula (2) below: 0.25 < I(100)Zn / {I(002)Zn + I(101)Zn + I(100)Zn} < 3.00 ••• (2).

7. Steel plated material according to any one of claims 1 to 6, characterized in that the Sn in the plated layer is 0.05 to 0.50% by mass, and a Mg2Sn phase is detected by the result of X-ray diffraction measurement of the plated layer. Petition 870250088824, dated 09 / 30 / 2025, pp. 51 / 53

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