JP6686653B2 - Plated steel - Google Patents
Plated steel Download PDFInfo
- Publication number
- JP6686653B2 JP6686653B2 JP2016080383A JP2016080383A JP6686653B2 JP 6686653 B2 JP6686653 B2 JP 6686653B2 JP 2016080383 A JP2016080383 A JP 2016080383A JP 2016080383 A JP2016080383 A JP 2016080383A JP 6686653 B2 JP6686653 B2 JP 6686653B2
- Authority
- JP
- Japan
- Prior art keywords
- layer
- steel material
- concentrated
- plating layer
- plated steel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 229910000831 Steel Inorganic materials 0.000 title claims description 36
- 239000010959 steel Substances 0.000 title claims description 36
- 239000010410 layer Substances 0.000 claims description 87
- 238000007747 plating Methods 0.000 claims description 40
- 239000000463 material Substances 0.000 claims description 30
- 239000002344 surface layer Substances 0.000 claims description 13
- 229910052725 zinc Inorganic materials 0.000 claims description 7
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 claims description 6
- 238000005260 corrosion Methods 0.000 description 16
- 230000007797 corrosion Effects 0.000 description 16
- 239000000047 product Substances 0.000 description 9
- 239000000126 substance Substances 0.000 description 9
- 239000011701 zinc Substances 0.000 description 9
- 238000000034 method Methods 0.000 description 8
- 238000004544 sputter deposition Methods 0.000 description 6
- 230000004580 weight loss Effects 0.000 description 6
- 239000013078 crystal Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 229910018134 Al-Mg Inorganic materials 0.000 description 3
- 229910018125 Al-Si Inorganic materials 0.000 description 3
- 229910018467 Al—Mg Inorganic materials 0.000 description 3
- 229910018520 Al—Si Inorganic materials 0.000 description 3
- 150000001450 anions Chemical class 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- FAPWRFPIFSIZLT-UHFFFAOYSA-M Sodium chloride Chemical compound [Na+].[Cl-] FAPWRFPIFSIZLT-UHFFFAOYSA-M 0.000 description 2
- 230000002378 acidificating effect Effects 0.000 description 2
- 229910000905 alloy phase Inorganic materials 0.000 description 2
- 230000003139 buffering effect Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000011247 coating layer Substances 0.000 description 2
- 239000012141 concentrate Substances 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000010828 elution Methods 0.000 description 2
- 229910000765 intermetallic Inorganic materials 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 230000007935 neutral effect Effects 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 0.000 description 1
- 238000000026 X-ray photoelectron spectrum Methods 0.000 description 1
- 229910009369 Zn Mg Inorganic materials 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 229910007573 Zn-Mg Inorganic materials 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000000862 absorption spectrum Methods 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001768 cations Chemical class 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 238000010406 interfacial reaction Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 239000011780 sodium chloride Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000004441 surface measurement Methods 0.000 description 1
Landscapes
- Other Surface Treatments For Metallic Materials (AREA)
Description
本発明は、めっき鋼材に係り、特に、めっき層の耐久性に優れるＺｎ−Ｍｇ系めっき鋼材に関する。 TECHNICAL FIELD The present invention relates to a plated steel material, and more particularly to a Zn—Mg based plated steel material having excellent durability of a plated layer.
表面処理鋼板の中には、Ｚｎ−Ａｌ−Ｍｇ系、Ｚｎ−Ｍｇ−Ａｌ−Ｓｉ系など、ＺｎおよびＭｇを含んだ表面処理皮膜が形成されているものが存在する。これら表面処理鋼板が使用環境で腐食されることによって、表面処理皮膜は消費され、やがて消失する。 Some surface-treated steel sheets have a surface-treated coating containing Zn and Mg, such as Zn-Al-Mg-based and Zn-Mg-Al-Si-based. When these surface-treated steel sheets are corroded in the use environment, the surface-treated film is consumed and eventually disappears.
そのため、特に腐食環境に長期間さらされる表面処理鋼板においては、耐久性の向上が課題となる。例えば、特許文献１には、ＡｌとＭｇを含有するＺｎ系めっき層を有する鋼板に有機被覆層を有する有機被覆鋼板が開示されている。また、特許文献２には、Ｍｇ含有亜鉛合金めっき層の上に、界面反応層を介して化成皮膜を形成する技術が開示されている。さらに、特許文献３には、金属間化合物を含む上層と合金相からなるめっき皮膜を形成する技術が開示されている。 Therefore, improvement of durability becomes a problem especially in the case of the surface-treated steel sheet that is exposed to a corrosive environment for a long time. For example, Patent Document 1 discloses an organic coated steel sheet having an organic coating layer on a steel sheet having a Zn-based plating layer containing Al and Mg. Further, Patent Document 2 discloses a technique of forming a chemical conversion film on an Mg-containing zinc alloy plating layer via an interfacial reaction layer. Further, Patent Document 3 discloses a technique of forming a plating film composed of an upper layer containing an intermetallic compound and an alloy phase.
しかしながら、特許文献１および２に記載の方法では、それぞれ、めっき層上に有機被覆層および化成皮膜を形成する必要があるため、コストの面で改善の余地がある。また、特許文献３の方法では皮膜と下地鋼材との界面に合金相を形成するとともに、皮膜中に金属間化合物を形成する必要があり、処理が複雑であるという問題がある。 However, in the methods described in Patent Documents 1 and 2, there is room for improvement in terms of cost because it is necessary to form an organic coating layer and a chemical conversion film on the plating layer, respectively. Further, in the method of Patent Document 3, it is necessary to form an alloy phase at the interface between the coating and the base steel material, and to form an intermetallic compound in the coating, which causes a problem of complicated processing.
本発明は、ＺｎおよびＭｇを含むめっき層のみが形成された状態であっても、めっき層の耐久性が大幅に向上されためっき鋼材を提供することを目的とする。 An object of the present invention is to provide a plated steel material in which the durability of the plating layer is significantly improved even when only the plating layer containing Zn and Mg is formed.
本発明は、上記の課題を解決するためになされたものであり、下記のめっき鋼材を要旨とする。 The present invention has been made in order to solve the above problems, and has as its gist the following plated steel material.
（１）ＺｎおよびＭｇを含むめっき層を有するめっき鋼材であって、
前記めっき層の表層部の少なくとも一部に、厚さが０．１〜２．０μｍであるＭｇ濃化層が形成され、
前記Ｍｇ濃化層は、原子％で、Ｍｇ：５．０％以上５０．０％未満およびＣ：３．０〜２０．０％を含む、めっき鋼材。
(1) A plated steel material having a plating layer containing Zn and Mg,
A Mg concentrated layer having a thickness of 0.1 to 2.0 μm is formed on at least a part of the surface layer of the plating layer,
The Mg concentrated layer is a plated steel material containing, in atomic%, Mg: 5.0% or more and less than 50.0% and C: 3.0 to 20.0%.
（２）前記Ｍｇ濃化層がＭｇ炭酸塩を含む、上記（１）に記載のめっき鋼材。 (2) The plated steel material according to (1), wherein the Mg concentrated layer contains Mg carbonate.
本発明によれば、めっき層の表層部にＭｇ濃化層をあらかじめ形成することによって、その後の劣悪な腐食環境において急激な腐食を抑制することが可能になり、めっき層の耐久性が向上する。 According to the present invention, by preliminarily forming the Mg concentrated layer on the surface layer portion of the plating layer, it becomes possible to suppress rapid corrosion in the subsequent poor corrosion environment, and the durability of the plating layer is improved. .
本発明らが種々の検討を行った結果、以下の知見を得るに至った。 As a result of various studies by the present inventors, the following findings have been obtained.
ＺｎおよびＭｇを含むめっき層を有するめっき鋼材をあらかじめ特定の条件の腐食環境下に保持すると、めっき層の表層部にＭｇおよびＣが濃化したＭｇ濃化層が形成される。そして、このＭｇ濃化層が形成されためっき層は、Ｍｇ濃化層を有しないめっき層と比較して、腐食環境下での耐久性に優れることを見出した。 When a plated steel material having a plating layer containing Zn and Mg is previously held in a corrosive environment under specific conditions, a Mg concentrated layer in which Mg and C are concentrated is formed on the surface layer portion of the plating layer. Then, it has been found that the plated layer having the Mg concentrated layer formed thereon has excellent durability in a corrosive environment, as compared with a plated layer having no Mg concentrated layer.
本発明は上記知見に基づいてなされたものである。以下、本発明の各要件について詳しく説明する。 The present invention has been made based on the above findings. Hereinafter, each requirement of the present invention will be described in detail.
本発明の一実施形態に係るめっき鋼材は、ＺｎおよびＭｇを含むめっき層を有する鋼材である。Ｍｇを含むめっき層について特に制限はないが、具体的に、Ｚｎ−Ａｌ−Ｍｇ系、Ｚｎ−Ｍｇ−Ａｌ−Ｓｉ系のめっきが含まれる。また、めっき層は電気めっき層であってもよく、溶融めっき層であってもよい。 A plated steel material according to an embodiment of the present invention is a steel material having a plating layer containing Zn and Mg. The plating layer containing Mg is not particularly limited, but specifically includes Zn-Al-Mg-based plating and Zn-Mg-Al-Si-based plating. The plated layer may be an electroplated layer or a hot-dip plated layer.
上記のめっきの成分についても特に制限は設けないが、通常、Ｚｎ−Ａｌ−Ｍｇ系であれば、質量％で、８５〜９５％のＺｎおよび２．０〜５．０％のＭｇが含有されており、Ｚｎ−Ｍｇ−Ａｌ−Ｓｉ系であれば、８０〜９０％のＺｎおよび２．０〜５．０％のＭｇが含有されている。 Although there is no particular limitation on the components of the plating described above, a Zn-Al-Mg-based material usually contains 85 to 95% by mass of Zn and 2.0 to 5.0% of Mg by mass. In the case of Zn-Mg-Al-Si system, 80 to 90% of Zn and 2.0 to 5.0% of Mg are contained.
また、本発明の一実施形態に係るめっき鋼材が有するめっき層は、めっき層の耐久性を向上させることを目的として、その表層部に厚さが０．１〜２．０μｍであるＭｇ濃化層が形成されている。厚さが０．１μｍ未満では、めっき層の耐久性を向上させる効果が得られない。一方、厚さが２．０μｍを超える濃化層を形成させようとすると、Ｍｇ以外の成分についても多く溶出する結果となるため、めっき鋼材のその後の製品寿命が短くなる。なお、めっき層の全てが該Ｍｇ濃化層に覆われている必要はなく、少なくとも一部が覆われていればよい。 In addition, the plated layer of the plated steel material according to one embodiment of the present invention has a Mg concentration of 0.1 to 2.0 μm at the surface layer for the purpose of improving the durability of the plated layer. Layers have been formed. If the thickness is less than 0.1 μm, the effect of improving the durability of the plating layer cannot be obtained. On the other hand, if an attempt is made to form a concentrated layer having a thickness of more than 2.0 μm, a large amount of components other than Mg will also be eluted, resulting in a shorter product life of the plated steel material. In addition, it is not necessary that the whole of the plated layer is covered with the Mg concentrated layer, and at least a part thereof may be covered.
めっき鋼材が腐食環境にさらされると、めっき層から溶け出した金属成分のカチオンと環境中から供給されるアニオンとが結合し、微細な結晶の混合物となってめっき層表層に沈殿する。この際、めっき層中に含まれるＭｇは高い犠牲防食作用を有するため、腐食により優先的に溶け出し、表層部で微細なＭｇＯ、Ｍｇ（ＯＨ）２、ＭｇＣＯ３等の結晶を形成し濃化することによって、他のめっき成分の溶出を抑制する効果を発揮する。 When the plated steel material is exposed to a corrosive environment, the cations of the metal components dissolved from the plating layer and the anions supplied from the environment are combined to form a mixture of fine crystals and precipitate on the surface layer of the plating layer. At this time, since Mg contained in the plating layer has a high sacrificial anticorrosive action, it preferentially dissolves due to corrosion and forms fine crystals of MgO, Mg (OH) 2 , MgCO 3 and the like in the surface layer portion to concentrate. By doing so, the effect of suppressing the elution of other plating components is exhibited.
この時、ＭｇがＣとともに濃化することによって、緩衝作用を発揮し、腐食環境にさらされた場合であっても、めっき層表面のｐＨが酸性側に低下するのを抑制し中性に近い状態に維持することが可能になる。これによって、めっき層の溶解を抑止しているものと考えられる。したがって、Ｍｇ濃化層にはＣが含まれている必要があり、Ｍｇ炭酸塩（ＭｇＣＯ３）として含まれていることが好ましい。 At this time, Mg concentrates together with C, thereby exerting a buffering effect, and even when exposed to a corrosive environment, it suppresses the pH of the plating layer surface from decreasing to an acidic side and is close to neutral. It becomes possible to maintain the state. It is considered that this prevents dissolution of the plating layer. Therefore, the Mg-enriched layer needs to contain C, and is preferably contained as Mg carbonate (MgCO 3 ).
Ｍｇ濃化層中に含まれるＭｇおよびＣの含有量は以下のように制限する。なお、以下の説明において含有量についての「％」は、「原子％」を意味する。 The content of Mg and C contained in the Mg concentrated layer is limited as follows. In the following description, “%” regarding the content means “atomic%”.
Ｍｇ：５．０％以上５０．０％未満
上述のように、Ｍｇ以外のめっき成分の溶出を抑制して、めっき層の耐久性を向上させる効果を発揮する。上記の効果を得るためには、Ｍｇ濃化層中に含まれるＭｇ含有量を５．０％以上とする必要がある。一方、Ｍｇ濃化層を構成する微細な結晶中に含まれるアニオンおよび後述するＣとのバランスから、Ｍｇ含有量は５０．０％未満となる。Ｍｇ含有量は１０．０％以上であるのが好ましく、３５．０％以下であるのが好ましい。
Mg: 5.0% or more and less than 50.0% As described above, the effect of suppressing the elution of plating components other than Mg and improving the durability of the plating layer is exhibited. In order to obtain the above effect, the Mg content contained in the Mg concentrated layer needs to be 5.0% or more. On the other hand, the Mg content is less than 50.0% due to the balance between the anions contained in the fine crystals forming the Mg concentrated layer and C described later. The Mg content is preferably 10.0% or more, and preferably 35.0% or less.
Ｃ：３．０〜２０．０％
Ｍｇ濃化層中にＣが含まれることによって緩衝作用を発揮し、腐食環境にさらされた場合であっても、めっき層表面のｐＨが酸性側に低下するのを抑制し、中性に近い状態に維持することが可能になる。上記の効果を得るためには、Ｍｇ濃化層中に含まれるＣ含有量を３．０％以上とする必要がある。一方、Ｍｇ濃化層を構成する微細な結晶中に含まれる他のアニオンおよび金属成分とのバランスから、Ｃ含有量は２０．０％以下となる。Ｃ含有量は５．０％以上であるのが好ましく、１５．０％以下であるのが好ましい。
C: 3.0 to 20.0%
By containing C in the Mg concentrated layer, it exerts a buffering effect, and suppresses the pH of the plating layer surface from decreasing to the acidic side even when exposed to a corrosive environment, and is close to neutral. It becomes possible to maintain the state. In order to obtain the above effect, the C content contained in the Mg concentrated layer needs to be 3.0% or more. On the other hand, the C content is 20.0% or less due to the balance with other anions and metal components contained in the fine crystals that form the Mg concentrated layer. The C content is preferably 5.0% or more, and preferably 15.0% or less.
本発明においては、Ｍｇ濃化層の厚さおよび化学成分は、Ｘ線光電子分光装置（ＸＰＳ）を用いてＡｒでスパッタリングしながら分析することにより測定することとする。Ｍｇ濃化層が形成されためっき層表層部について、Ｍｇの深さ方向における濃度プロファイルを観察すると、Ｍｇ含有量は所定の深さにおいて最大値を示し、両端に向かうほど低くなるピーク形状を呈する。本発明においては、Ｍｇ含有量が前記最大値の半分以上となる範囲をＭｇ濃化層とし、Ｍｇ濃化層の厚さを測定するとともに、当該厚さ範囲での化学成分の平均値をＭｇ濃化層の化学成分とする。 In the present invention, the thickness and chemical composition of the Mg concentrated layer are to be measured by analyzing while using Ar using an X-ray photoelectron spectrometer (XPS) while sputtering. When the concentration profile in the depth direction of Mg is observed in the plating layer surface layer portion where the Mg concentrated layer is formed, the Mg content shows a maximum value at a predetermined depth, and exhibits a peak shape that becomes lower toward both ends. . In the present invention, the range in which the Mg content is half or more of the maximum value is defined as the Mg enriched layer, the thickness of the Mg enriched layer is measured, and the average value of the chemical components in the thickness range is Mg. It is used as the chemical component of the concentrated layer.
また、Ｍｇ濃化層中のＭｇ炭酸塩の有無については、例えば、Ｘ線吸収微細構造（ＸＡＦＳ）を用いた、全電子収量法に基づき判定することができる。 Further, the presence or absence of Mg carbonate in the Mg concentrated layer can be determined based on, for example, the total electron yield method using X-ray absorption fine structure (XAFS).
なお、本発明の一実施形態に係るめっき鋼材は、Ｍｇ濃化層の上にさらに他の腐食生成物または有機皮膜等が形成されていてもよい。 The plated steel material according to one embodiment of the present invention may further have another corrosion product or an organic film formed on the Mg concentrated layer.
Ｍｇ濃化層を形成する方法について、特に制限はないが、ＺｎおよびＭｇを含むめっき層を有するめっき鋼材をあらかじめ温度および湿度を制御した腐食環境下に保持することによって形成することが可能である。具体的には、雰囲気温度が４５℃以上で、かつ、相対湿度が８０％以上である大気中の腐食環境下に１ｈ以上保持することが好ましい。 The method for forming the Mg concentrated layer is not particularly limited, but it can be formed by holding a plated steel material having a plating layer containing Zn and Mg in a corrosive environment in which temperature and humidity are controlled in advance. . Specifically, it is preferable to keep the temperature for 1 h or more in a corrosive environment in the atmosphere where the atmospheric temperature is 45 ° C. or higher and the relative humidity is 80% or higher.
雰囲気温度および湿度の双方が低いと、Ｍｇ濃化層は十分に厚く形成されない。また、雰囲気温度が低い状態で湿度のみを高めた場合、めっき層の表層部に形成される層中のＭｇ濃度が低くなる。そして、湿度が低い状態で雰囲気温度のみを高めた場合、層中に含まれる微結晶としてＭｇＯが優勢となり、Ｃ濃度が低くなる。 When both the ambient temperature and the humidity are low, the Mg concentrated layer cannot be formed sufficiently thick. Further, when only the humidity is increased in a state where the atmospheric temperature is low, the Mg concentration in the layer formed in the surface layer portion of the plating layer becomes low. Then, when only the atmospheric temperature is raised in a low humidity state, MgO becomes predominant as fine crystals contained in the layer, and the C concentration becomes low.
ＭｇおよびＣが濃化したＭｇ濃化層は水溶性であるため、高温高湿度の大気環境が層形成に好適である。雰囲気温度は５５℃以上とすることがより好ましく、相対湿度は９０％以上とすることがより好ましい。 Since the Mg concentrated layer in which Mg and C are concentrated is water-soluble, an atmospheric environment of high temperature and high humidity is suitable for layer formation. The ambient temperature is more preferably 55 ° C. or higher, and the relative humidity is more preferably 90% or higher.
以下、実施例によって本発明をより具体的に説明するが、本発明はこれらの実施例に限定されるものではない。 Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to these examples.
めっき層の組成がＺｎ−１１％Ａｌ−３％Ｍｇ−０．２％Ｓｉ、目付量が４５ｇ／ｍ２／片面であるめっき鋼材から、７０ｍｍ×１５０ｍｍのサイズの試験片（鋼材Ｎｏ．１〜５）を採取し、あらかじめ表１に示す条件の大気環境中に保持することによって、めっき層表層部に二次生成物（腐食生成物）を形成させた。 From a plated steel material having a composition of the plated layer of Zn-11% Al-3% Mg-0.2% Si and a basis weight of 45 g / m 2 / one side, a test piece of 70 mm × 150 mm (steel material No. 1 By collecting 5) and holding it in the atmospheric environment under the conditions shown in Table 1, a secondary product (corrosion product) was formed in the surface layer of the plating layer.
得られた試料について、めっき層の表層部に形成された二次生成物の厚さおよび化学成分を、ＸＰＳを用いてＡｒでスパッタリングしながら分析することにより測定した。ＸＰＳによるＭｇの深さ方向における濃度プロファイルを観察すると、Ｍｇ含有量は所定の深さにおいて最大値を示し、両端に向かうほど低くなるピーク形状を呈する。Ｍｇ含有量が前記最大値の半分以上となる範囲をＭｇ濃化層とし、Ｍｇ濃化層の厚さを測定するとともに、当該厚さ範囲での化学成分の平均値をＭｇ濃化層の化学成分とした。 With respect to the obtained sample, the thickness and chemical composition of the secondary product formed on the surface layer portion of the plating layer were measured by analyzing the thickness and chemical composition of the secondary product while sputtering with Ar using XPS. When the concentration profile of Mg in the depth direction by XPS is observed, the Mg content has a maximum value at a predetermined depth and has a peak shape that decreases toward both ends. The range in which the Mg content is half or more of the maximum value is defined as the Mg-enriched layer, the thickness of the Mg-enriched layer is measured, and the average value of the chemical components in the thickness range is calculated as the chemistry of the Mg-enriched layer. As an ingredient.
測定条件の詳細は以下に示すとおりである。 The details of the measurement conditions are as shown below.
（ＸＰＳ元素分析測定条件）
光源 ：単色化したＡｌ−Ｋα線（１４８６．６ｅＶ）
Ｘ線ビーム径 ：１００μｍ×１００μｍ
Ｘ線入射方向 ：試料表面の法線方向に対して４５°
光電子捕獲方向 ：試料表面の法線方向に対して４５°
測定方法 ：Ａｒスパッタリングにより表面を削りながらＸＰＳスペクトルを測定
Ａｒスパッタ域 ：１ｍｍ×１ｍｍ
Ａｒイオン入射方向：試料表面の法線方向
表面からの深さ ：膜厚既知のＳｉＯ２／Ｓｉにてスパッタリング速度を測定し、スパッタ時間を表面からの深さに換算
(XPS element analysis measurement conditions)
Light source: Monochromatic Al-Kα ray (1486.6 eV)
X-ray beam diameter: 100 μm × 100 μm
X-ray incident direction: 45 ° to the normal direction of the sample surface
Photoelectron capture direction: 45 ° to the normal direction of the sample surface
Measurement method: XPS spectrum is measured while shaving the surface by Ar sputtering Ar sputtering area: 1 mm x 1 mm
Ar ion incident direction: normal to sample surface Depth from surface: Sputtering speed was measured with SiO 2 / Si of known film thickness, and sputtering time was converted to depth from surface
また、Ｍｇ濃化層中のＭｇ炭酸塩の有無については、ＸＡＦＳを用いた、全電子収量法により求めた。具体的には、Ｍｇを対象としたＸ線吸収スペクトルの形状を観察し、Ｍｇ炭酸塩の有無を判断した。それらの結果を表２に示す。 The presence or absence of Mg carbonate in the Mg concentrated layer was determined by the total electron yield method using XAFS. Specifically, the shape of the X-ray absorption spectrum for Mg was observed to determine the presence or absence of Mg carbonate. The results are shown in Table 2.
その後、鋼材Ｎｏ．１〜５のめっき鋼材を用いて腐食試験を行った。腐食試験は、日本自動車技術会規格ＪＡＳＯ Ｍ６０９−９１に準拠して行った。具体的には、３５℃の５％ＮａＣｌ溶液を２ｈ噴霧した後、６０℃、相対湿度３０％の環境下で４ｈ乾燥させ、その後さらに、５０℃、相対湿度９５％の湿潤環境に２ｈ保持するというサイクルを１０サイクル繰り返した。そして、腐食試験を行う前後の試料の断面観察を行い、めっき層の腐食減量を測定した。その結果を表２に併せて示す。なお、本発明においては、腐食減量が３．０ｇ／ｍ２未満となった場合に、めっき層の耐久性に優れると判断することとした。 After that, the steel material No. A corrosion test was conducted using the plated steel materials 1 to 5. The corrosion test was performed based on Japan Society of Automotive Engineers Standard JASO M609-91. Specifically, after spraying a 5% NaCl solution at 35 ° C. for 2 h, it is dried for 4 h in an environment of 60 ° C. and a relative humidity of 30%, and then kept in a humid environment of 50 ° C. and a relative humidity of 95% for 2 h. This cycle was repeated 10 times. Then, the cross-section of the sample was observed before and after the corrosion test, and the corrosion weight loss of the plating layer was measured. The results are also shown in Table 2. In the present invention, it was decided that the durability of the plated layer was excellent when the corrosion weight loss was less than 3.0 g / m 2 .
表２から分かるように、鋼材Ｎｏ．３では、二次生成物の厚さが０．１μｍ未満となったため、めっき層の耐久性が改善されず、腐食減量が大きくなる結果となった。また、鋼材Ｎｏ．４では、二次生成物の厚さが不十分であり、さらに、Ｍｇが濃化しなかった。その結果、めっき層の耐久性が劣り、腐食減量も比較的大きな値となった。鋼材Ｎｏ．５では、二次生成物は形成されたものの、ＭｇＯの生成が優勢となり、Ｃ含有量が本発明で規定される下限値未満となり、めっき層の耐久性が劣る結果となった。そのため、腐食減量も大きな値となった。 As can be seen from Table 2, the steel material No. In No. 3, since the thickness of the secondary product was less than 0.1 μm, the durability of the plating layer was not improved and the corrosion weight loss was increased. In addition, the steel material No. In No. 4, the secondary product had an insufficient thickness, and Mg was not concentrated. As a result, the durability of the plating layer was poor and the corrosion weight loss was a relatively large value. Steel material No. In No. 5, although the secondary product was formed, the production of MgO was predominant, the C content was less than the lower limit defined by the present invention, and the durability of the plating layer was poor. Therefore, the corrosion weight loss was also large.
これらに対して、本発明の規定を満足する鋼材Ｎｏ．１および２では、ＭｇＣＯ３を含み、規定範囲内の化学成分を有するＭｇ濃化層がめっき層の表層部に形成された。そのため、比較例の鋼材と比較して、耐久性が大幅に向上しており、腐食減量が低くなる結果となった。 On the other hand, steel material Nos. In 1 and 2, the Mg concentrated layer containing MgCO 3 and having a chemical component within the specified range was formed in the surface layer portion of the plating layer. Therefore, compared with the steel materials of Comparative Examples, the durability was significantly improved, and the corrosion weight loss was low.
本発明によれば、めっき層の表層部にＭｇ濃化層をあらかじめ形成することによって、その後の劣悪な腐食環境において急激な腐食を抑制することが可能になり、めっき層の耐久性が向上する。したがって、本発明に係るめっき鋼材は、家電、建築物の内面および高級自動車等に用いられる鋼材として好適に用いることができる。 According to the present invention, by preliminarily forming the Mg concentrated layer on the surface layer portion of the plating layer, it becomes possible to suppress rapid corrosion in the subsequent poor corrosion environment, and the durability of the plating layer is improved. . Therefore, the plated steel material according to the present invention can be suitably used as a steel material for home appliances, inner surfaces of buildings, high-class automobiles, and the like.
Claims (2)
前記めっき層の表層部の少なくとも一部に、厚さが０．１〜２．０μｍであるＭｇ濃化層が形成され、
前記Ｍｇ濃化層は、原子％で、Ｍｇ：５．０％以上５０．０％未満およびＣ：５．０〜２０．０％を含む、めっき鋼材。 A plated steel material having a plated layer containing Zn and Mg,
A Mg concentrated layer having a thickness of 0.1 to 2.0 μm is formed on at least a part of the surface layer of the plating layer,
The Mg concentrated layer is a plated steel material containing, in atomic%, Mg: 5.0% or more and less than 50.0% and C: 5.0 to 20.0%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016080383A JP6686653B2 (en) | 2016-04-13 | 2016-04-13 | Plated steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2016080383A JP6686653B2 (en) | 2016-04-13 | 2016-04-13 | Plated steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2017190489A JP2017190489A (en) | 2017-10-19 |
| JP6686653B2 true JP6686653B2 (en) | 2020-04-22 |
Family
ID=60086174
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2016080383A Expired - Fee Related JP6686653B2 (en) | 2016-04-13 | 2016-04-13 | Plated steel |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP6686653B2 (en) |
Family Cites Families (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0420795A (en) * | 1990-05-14 | 1992-01-24 | Sumitomo Light Metal Ind Ltd | Aluminum brass made heat exchange pipe |
| JP3545051B2 (en) * | 1994-06-14 | 2004-07-21 | 日新製鋼株式会社 | Zn-Mg based plated steel sheet excellent in corrosion resistance and manufacturing method |
| JPH09143679A (en) * | 1995-11-20 | 1997-06-03 | Nisshin Steel Co Ltd | Black zinc-magnesium plated steel sheet and its production |
| JPH1068063A (en) * | 1996-08-26 | 1998-03-10 | Nisshin Steel Co Ltd | Zinc-magnesium series plated steel sheet excellent in blackening treatability and production of black zinc-magnesium series plated steel sheet |
| JPH10183372A (en) * | 1996-12-25 | 1998-07-14 | Nisshin Steel Co Ltd | Black zinc-magnesium series plated steel sheet excellent in weldability and blackening treating method |
| JP4064634B2 (en) * | 2001-02-02 | 2008-03-19 | 日新製鋼株式会社 | Hot-dip Zn-based plated steel sheet with good gloss retention and method for producing the same |
| US6677058B1 (en) * | 2002-07-31 | 2004-01-13 | Nisshin Steel Co., Ltd. | Hot-dip Zn plated steel sheet excellent in luster-retaining property and method of producing the same |
| JP4377743B2 (en) * | 2004-05-06 | 2009-12-02 | 新日本製鐵株式会社 | High corrosion resistance galvannealed steel sheet |
| JP4630099B2 (en) * | 2005-03-25 | 2011-02-09 | 株式会社神戸製鋼所 | Hot-dip hot-dip galvanized steel sheet with excellent phosphatability and post-coating corrosion resistance and method for producing the same |
| JP2007023309A (en) * | 2005-07-12 | 2007-02-01 | Nisshin Steel Co Ltd | Hot-dip zinc alloy plated steel sheet having excellent corrosion resistance |
| JP5332848B2 (en) * | 2009-04-10 | 2013-11-06 | 新日鐵住金株式会社 | Organic composite Mg-based plated steel sheet |
| KR20120075235A (en) * | 2010-12-28 | 2012-07-06 | 주식회사 포스코 | Hot dip zn alloy plated steel sheet having excellent anti-corrosion and method for manufacturing the steel sheet using the same |
| AT514229B1 (en) * | 2013-04-29 | 2015-02-15 | Voestalpine Stahl Gmbh | Process for the surface treatment of a metallic substrate |
| WO2015001368A1 (en) * | 2013-07-04 | 2015-01-08 | Arcelormittal Investigaciòn Y Desarrollo Sl | Sheet metal treatment method for reducing blackening or tarnishing during the storage thereof, and metal sheet treated with this method |
-
2016
- 2016-04-13 JP JP2016080383A patent/JP6686653B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2017190489A (en) | 2017-10-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP6653026B2 (en) | Solution composition for surface treatment of steel sheet, galvanized steel sheet surface-treated using the same, and method for producing the same | |
| CA2947403C (en) | Hot-dip al-based alloy coated steel sheet excellent in workability | |
| AU2014240655B2 (en) | Hot-dip Al-Zn alloy coated steel sheet and method for producing same | |
| WO2014119268A8 (en) | HOT-DIP Al-Zn ALLOY COATED STEEL SHEET AND METHOD FOR PRODUCING SAME | |
| CA2915780A1 (en) | Sheet metal treatment method for reducing blackening or tarnishing during the storage thereof, and metal sheet treated with this method | |
| US11155926B2 (en) | Method for the production of metal sheet having a ZnMg or ZnAlMg coating, comprising the application of a basic solution of a magnesium ion complexing agent, and resulting metal sheet | |
| KR102081360B1 (en) | Insulating film of electronic steel sheet | |
| JP6742524B2 (en) | Zn-Mg alloy plated steel with excellent corrosion resistance and plating adhesion | |
| JP5733667B2 (en) | External spray tube | |
| JP6686653B2 (en) | Plated steel | |
| MX2020005506A (en) | Aluminum-plated steel sheet, method for producing aluminum-plated steel sheet and method for producing component for automobiles. | |
| JP6455525B2 (en) | Electrical steel sheet | |
| Shimoda et al. | Corrosion resistance of several Zn-Al-Mg alloy coated steels | |
| JP2017035877A (en) | Anticorrosive coated steel material, manufacturing method therefor, and anticorrosive method of coated steel material | |
| JP6686654B2 (en) | Method for producing plated steel | |
| JP2018103123A (en) | Corrosion proof coated steel material, manufacturing method for the same, and corrosion proof method for coated steel material | |
| JPH083728A (en) | Zinc-magnesium plated steel sheet excellent in corrosion resistance and its production | |
| JP2014534351A (en) | Dry appropriate amount corrosion resistant coating for zinc or zinc alloy coated substrate | |
| JP5995438B2 (en) | Method for manufacturing outer surface anticorrosive body | |
| JP2002256407A (en) | Hot-dipped aluminum plated steel-sheet showing black color, and manufacturing method therefor | |
| JP5594998B2 (en) | Anticorrosive body and manufacturing method thereof | |
| JP2020066793A (en) | Surface treatment liquid and manufacturing method of surface-treated steel plate and surface-treated steel plate | |
| JP7436840B2 (en) | Hot-dip Zn-Al-Mg plated steel | |
| JP2007224361A (en) | Tinned steel sheet | |
| JP5721882B2 (en) | Method for manufacturing outer surface anticorrosive body |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20181206 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20190816 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20190827 |
|
| A521 | Request for written amendment filed |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20191021 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20200303 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20200316 |
|
| R151 | Written notification of patent or utility model registration |
Ref document number: 6686653 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| LAPS | Cancellation because of no payment of annual fees |