JP4980266B2 - High corrosion resistance plated steel material and method for producing the same - Google Patents

Description

  The present invention relates to a highly corrosion-resistant plated steel material, and more particularly to a highly corrosion-resistant nickel-plated steel material, and more particularly to a plated steel material having a relatively low adhesion amount and extremely good corrosion resistance and a method for producing the same.

  In many cases, nickel plating is applied to steel materials used for electrical and electronic appliances, container materials represented by battery cans, daily household electrical appliance members such as binders, and the like from the viewpoints of corrosion resistance, design properties, low electrical resistance, and the like. Nickel is stable to various chemicals in the natural environment, has excellent heat resistance, and has little change in the appearance of its surface. Therefore, various developments other than the above applications are expected. However, since nickel is electrically nobler than steel, sacrificial anticorrosive action like zinc-based plating cannot be expected, and iron rust (red rust) from plating pinholes, which is unavoidably present at the plating thickness usually used ) Occurrence may be a problem. In order to avoid this, it is necessary to take a very economically disadvantageous measure such as extremely increasing the amount of nickel deposited, so the application range is extremely limited compared to zinc-based plated steel materials. As a means to ensure corrosion resistance without increasing the amount of nickel deposited, techniques using Fe-Ni diffusion treatment, lower layer plating, etc. have been studied so far, but those having sufficient effects have been found. Absent.

For example, Patent Document 1 discloses a highly corrosion-resistant Ni-plated steel strip in which a part or all of the Ni plating layer is an Fe—Ni diffusion layer and the Fe exposure rate of the surface layer is 30% or less. By providing an Fe-Ni diffusion layer, pinholes are reduced and the potential difference corrosion between noble Ni and base Fe is alleviated, so a certain corrosion resistance improvement effect can be obtained, but a more severe corrosive environment Is not necessarily sufficient. In particular, the region where the amount of deposited Ni is as low as 40 g / m ² or less is not sufficient.

  In addition, the lower layer plating is a technical idea that improves corrosion resistance even if pinholes exist, by providing a Zn-based plating layer below the Ni plating and combining sacrificial anticorrosive ability. No. 2 discloses a steel plate having a Zn plating layer as a lower layer and a Ni plating layer as an upper layer although it is limited to a fuel tank application. In this case, since the potential difference between Zn and Ni is large, the corrosion of Zn is remarkably accelerated depending on the corrosive environment, and white rust (Zn rust) appears on the surface layer of Ni, so that the appearance deteriorates significantly. There's a problem. In addition, there is a problem that red rust is generated in a short time unless the amount of deposited Zn in the lower layer is significantly increased. In addition, in this configuration, there is a problem that the diffusion layer as in Patent Document 1 cannot be used because of the influence of low boiling point of Zn and easy formation of brittle intermetallic compounds with Fe and Ni.

JP-A-6-2104 Japanese Patent Laid-Open No. 62-27587

  The present invention provides a highly corrosion-resistant plated steel material that effectively suppresses the occurrence of iron rust caused by plated pinholes without impairing the characteristics of Ni-plated steel materials such as corrosion resistance, design properties, and low electrical resistance, and a method for producing the same. With the goal.

  In order to improve the corrosion resistance of Ni-plated steel materials, the present inventors have come up with the present invention through various studies based on the concept of providing a diffusion layer and sacrificial anticorrosive ability.

That is, the configuration of the highly corrosion-resistant plated steel material of the present invention is
(1) A high corrosion-resistant plated steel material having at least one of a Fe—Mn diffusion layer and a Fe—Mn—Ni diffusion layer on a steel base material, and further having a Ni plating layer on the surface layer .
(2) The Mn-Ni diffusion layer is provided between the Ni plating layer on the surface layer and the Fe-Mn diffusion layer or the Fe-Mn-Ni diffusion layer. High corrosion resistance plated steel.
(3) The steel base material has at least one of an Fe—Mn diffusion layer and an Fe—Mn—Ni diffusion layer, and further has a Mn—Ni diffusion layer or an Fe—Mn—Ni diffusion layer on the surface layer. High corrosion-resistant plated steel, characterized by
(4) The high corrosion resistance plated steel material according to (3), wherein the Ni concentration in the Mn—Ni diffusion layer or the Fe—Mn—Ni diffusion layer as the outermost layer is 60% by mass or more.
(5) The high corrosion-resistant plated steel material according to any one of (1) to (4), wherein the total adhesion amount of Ni contained in the plating layer and the diffusion layer is 5 to 40 g / m ^2. .
(6) The high corrosion resistance according to any one of (1) to (5), wherein a total adhesion amount of Mn contained in the plating layer and the diffusion layer is 0.1 to 20 g / m ^2. Plated steel.
It is.

Further, the present invention is a method for producing a highly corrosion-resistant plated steel material,
(7) Mn plating and Ni plating are applied to the steel material in this order, followed by thermal diffusion treatment, and at least one of the Fe—Mn diffusion layer and the Fe—Mn—Ni diffusion layer is provided on the steel material. A method for producing a highly corrosion-resistant plated steel material.
(8) A method for producing a highly corrosion-resistant plated steel material, wherein the steel material is subjected to Mn plating, then subjected to thermal diffusion treatment, and after the Fe—Mn diffusion layer is provided on the steel material, Ni plating is performed.
(9) The method for producing a highly corrosion-resistant plated steel material according to (8), wherein a thermal diffusion treatment is further performed after Ni plating to provide a Mn—Ni diffusion layer.
(10) Mn plating and Ni plating are applied to the steel material in this order, followed by thermal diffusion treatment, and at least one of a Fe—Mn diffusion layer and a Fe—Mn—Ni diffusion layer is provided on the steel material. After that, a method for producing a highly corrosion-resistant plated steel material, wherein Ni plating is performed.
(11) The high corrosion resistance according to (10), wherein after the Ni plating after the thermal diffusion treatment, a thermal diffusion treatment is further performed to provide a Mn—Ni diffusion layer or a Fe—Mn—Ni diffusion layer. Manufacturing method of plated steel.
It is.

  High corrosion resistance that effectively suppresses the occurrence of iron rust caused by plated pinholes by combining the sacrificial anti-corrosion effect without compromising the characteristics of Ni-plated steel materials such as corrosion resistance, designability, and low electrical resistance. A plated steel material is obtained.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

  The first configuration of the highly corrosion-resistant plated steel material of the present invention is characterized in that it has a Fe-Mn diffusion layer or a Fe-Mn-Ni diffusion layer or both on the steel base material, and a Ni layer on the surface layer. To do. An example of the typical configuration is shown in FIGS. 1 to 6 as schematic diagrams. The diffusion layer is a layer formed as a result of element diffusion by heat treatment to be described later. These configurations include a method of observing the element distribution in the depth direction from the surface layer by a method such as GDS (Glow Discharge Spectrometry) and AES (Auger Electron Spectroscopy), or SEM (Scanning Electron Microspe Spec. X). It can be specified by a method of observing the elemental distribution of the cross section by a method such as -ray Spectrometer) or EPMA (Electron Probe Micro Analyzer). The surface Ni layer in FIGS. 1 to 6 may be a layer that remains partially undiffused when the diffusion layer is formed, or may be a layer that is Ni-plated again after the diffusion layer is formed. The Fe—Mn diffusion layer or the Fe—Mn—Ni diffusion layer can suppress damage to the plating layer even in severe processing, and also relaxes the potential gap between the steel base material and the plating surface layer, and is electrochemical. Has the effect of inhibiting corrosion. From the viewpoint of further relaxing the potential gap with the steel base material, as shown in FIGS. 1 to 3, it is desirable that a Mn—Ni diffusion layer exists in the lower layer of the surface Ni layer. Good corrosion resistance can be obtained even with a relatively low amount of plating. The first configuration of the present application having the Ni layer as the outermost layer is a preferable configuration when importance is attached to the gloss appearance or resistance to chemicals such as strong alkali.

  The second configuration of the highly corrosion-resistant plated steel material of the present invention has a Fe—Mn diffusion layer or a Fe—Mn—Ni diffusion layer or both on the steel base material, and a Mn—Ni diffusion layer or Fe— on the surface layer. It is characterized by having a Mn-Ni diffusion layer. An example of the typical configuration is shown in FIGS. 7 to 11 as schematic diagrams. As described above, the diffusion layer has the action of suppressing damage to the plating layer in severe processing and suppressing electrochemical corrosion by relaxing the potential gap between the steel base material and the plating surface layer. In addition, since the diffusion layer which is an alloy layer is the outermost layer, it is excellent in adhesion to organic substances and corrosion resistance to organic solvents, and is preferable for applications to be coated and to contact with organic solvents. In consideration of corrosion resistance, the Ni concentration in the outermost Mn—Ni diffusion layer or Fe—Mn—Ni diffusion layer is preferably 60% by mass or more. The Ni concentration in the outermost layer is the depth at which the oxygen intensity of the oxide film unavoidably present in the outermost layer portion is reduced to the base level by performing element distribution in the depth direction from the surface layer by a method such as AES (usually several nm to several tens of nm).

In the range of the high corrosion resistance plated steel material of the present invention, the corrosion resistance depends on the total adhesion amount of Ni and Mn (the adhesion amount in the diffusion layer and the plating layer), and the range is Ni. Is 5 to 40 g / m ² , and Mn is 0.1 to 20 g / m ² . If Ni is less than 5 g / m ² , the corrosion resistance is insufficient, and if it exceeds 40 g / m ² , the effect is saturated, which is uneconomical. A more desirable Ni adhesion amount range is 10 g / m ² or more, and higher corrosion resistance can be obtained in this range. On the other hand, if Mn is less than 0.1 g / m ² , the sacrificial anticorrosive ability is not exhibited and red rust is generated through the Ni pinhole. Moreover, even if it exceeds 20 g / m < ² >, an effect is saturated and it is uneconomical, and discoloration in a corrosive environment may occur easily. A more desirable Mn deposition amount range is 1 g / m ² or more, and higher corrosion resistance can be obtained in this range.

  Next, a method for producing the highly corrosion-resistant plated steel material of the present invention will be described. The methods are the following five methods. The first method is characterized in that the steel material is subjected to Mn plating and Ni plating in this order, and then subjected to thermal diffusion treatment. The second method is characterized in that the steel material is subjected to Mn plating, followed by thermal diffusion treatment, and then Ni plating. The third method is characterized in that the steel material is subjected to Mn plating and Ni plating in this order, followed by heat diffusion treatment, and then Ni plating. The fourth method is characterized in that the steel material is subjected to Mn plating, then heat diffusion treatment is performed, Ni plating is performed thereafter, and heat diffusion treatment is performed again. The fifth method is characterized in that the steel material is subjected to Mn plating and Ni plating in this order, followed by thermal diffusion treatment, then further Ni plating, and then thermal diffusion treatment again. In any of the methods, Mn plating, Ni plating, and thermal diffusion treatment are essential requirements, and the respective essential requirements and manufacturing methods will be described in detail below.

  Mn plating is not particularly limited, and includes inevitable impurity levels of C, N, S, O, P, B, Fe, Co, Sn, Cu, Zn, Ni, etc. in addition to pure Mn. It may be. However, for C, N, S, and O, incorporated are so-called gloss additives, semi-gloss additives, leveling additives, etc., which are added to improve the uniformity and smoothness of the plating layer. In this case, the concentration in the plating layer is in the range of the trace amount to about 0.1% by mass. The plating means may be electroplating or electroless plating, but electroplating is common. A sulfuric acid bath, a chloride bath, or the like is used for the plating bath.

  The Ni plating is not particularly limited, and may include C, N, S, O, P, B, Fe, Co, Sn, Cu, Mn and the like in addition to pure Ni. These elements include not only inevitable impurities but also those added positively. For example, for C, N, S, and O, incorporated so-called gloss additives, semi-gloss additives, leveling additives, etc., added to improve the hardness and smoothness of the Ni plating layer And the density | concentration in the plating layer is the range of trace amount-about 0.1 mass%. For P and B, in addition to those incorporated as a reducing agent for electroless plating described later, including those added for improving chemical resistance and hardness of the plating layer, the concentration in the plating layer is a trace. The amount is in the range of about 15% by mass. About Fe, Co, Sn, Cu, and Mn, those added for improving the chemical resistance and hardness of the plating layer are included, and the concentration in the plating layer is in the range of trace amount to about 50 mass%. . Any element exceeding the above-mentioned upper limit is not preferable because it causes problems such as brittleness of the plating layer and deterioration of contact resistance. The plating means may be electroplating or electroless plating. In the case of electroplating, a sulfuric acid bath, a chloride bath, a watt bath, a sulfamic acid bath, or the like is used. In the case of electroless plating, hypophosphorous acid, a boron compound, or the like is used as a reducing agent. In addition, spray treatment or immersion treatment with an alkaline aqueous solution or an acidic aqueous solution can be performed as a pretreatment for Ni plating as necessary.

  The thermal diffusion treatment can be performed by a normal heating method, and both a batch heating method and a continuous heating method are used. It is also possible to use both together. In consideration of the material characteristics of the steel material to be plated, it is preferable to perform the heat diffusion treatment and the annealing treatment at the same time. In this case, the heat treatment can be performed in a normal annealing furnace, and batch annealing and continuous annealing can be performed. Either of them may be used, or both may be used in combination. If the conditions are described, in batch heating or batch annealing, the steel material temperature is 450 to 650 ° C, preferably 500 to 600 ° C, for several hours to several tens of hours, preferably 6 to 24 hours, In continuous heating or continuous annealing, the steel material temperature is 700 to 900 ° C, preferably 700 to 850 ° C, and the soaking time is several seconds to several tens of minutes, usually 10 seconds to 120 seconds.

  In the first production method of the present invention, Mn plating, Ni plating, and thermal diffusion treatment are performed under the above-described conditions. It is also preferable to perform temper rolling after the thermal diffusion treatment, and the surface roughness of the plated steel material can be controlled by adjusting the roll roughness at that time.

  In the second production method of the present invention, Mn plating and thermal diffusion treatment are performed under the above-described conditions, and then Ni plating is performed. It is also preferable to perform temper rolling after heat diffusion treatment or after Ni plating, and it is also possible to control the surface roughness of the plated steel material by adjusting the roll roughness at that time. In addition, since a stable oxide film is likely to be formed on the Mn surface layer during the thermal diffusion treatment, the Ni plating pretreatment is strengthened more than usual (for example, the immersion treatment time is increased or the spraying amount is increased. Need to).

  In the third production method of the present invention, the second thermal diffusion treatment is performed after performing the Mn plating, the thermal diffusion treatment, and the Ni plating in the second production method described above. In this case, considering the material of the steel material, it is desirable that the first thermal diffusion treatment is a high temperature treatment by continuous annealing, and the subsequent thermal diffusion treatment is a low temperature treatment by batch annealing. By performing the thermal diffusion treatment twice as described above, the structure of the plating layer can be arbitrarily controlled. That is, for example, when the structure of the plating layer as shown in FIG. 9 is formed by one thermal diffusion treatment after Mn plating and Ni plating, the lower layer becomes a Fe—Mn—Ni diffusion layer with a slight temperature variation. Or the surface layer becomes a Fe—Mn—Ni diffusion layer and lacks stability, but if it is a process of Mn plating, thermal diffusion treatment, Ni plating, thermal diffusion treatment, the plating structure as shown in FIG. Can be formed. In the case of this manufacturing method, it is also preferable to perform temper rolling either after thermal diffusion treatment, after Ni plating, or after rethermal diffusion treatment, and plating by adjusting the roll roughness at that time It is possible to control the surface roughness of the steel material.

  In the fourth manufacturing method of the present invention, Mn plating, Ni plating, and thermal diffusion treatment are performed under the above-described conditions, and then Ni plating is performed again. It is also suitable to perform temper rolling after heat diffusion treatment or after Ni plating, and the surface roughness of the plated steel material can be controlled by adjusting the roll roughness at that time.

  The fifth production method of the present invention is a process of Mn plating and Ni plating, thermal diffusion treatment, Ni plating, thermal diffusion treatment, and performs two thermal diffusion treatments. By performing the thermal diffusion treatment twice as described above, the structure of the plating layer can be arbitrarily controlled. Also in this case, considering the material of the steel material, it is desirable that the first thermal diffusion treatment is a high temperature treatment by continuous annealing, and the subsequent thermal diffusion treatment is a low temperature treatment by batch annealing. In the case of this production method, it is also preferable to perform temper rolling after thermal diffusion treatment, after Ni plating, or after rethermal diffusion treatment, by adjusting the roll roughness at that time. It is possible to control the surface roughness of the plated steel material.

  Hereinafter, the present invention will be described more specifically with reference to examples.

(Examples 1-3)
Using an ultra-low carbon steel sheet (non-recrystallized steel sheet) added with Nb and Ti as a base plate, after degreasing and pickling treatment, the electric Mn plating is 1 g / m ^{2 under} the conditions shown in Table 1, and the electric Ni is under the conditions shown in Table 2. Plating 15g / m ² was performed in this order, and then thermal diffusion treatment was performed. Finally, temper rolling was performed. The thermal diffusion treatment is performed in a continuous annealing furnace in a 5% H ₂ containing N ₂ atmosphere (dew point −40 ° C.) in a temperature range of 700 to 850 ° C. (Example 1: 700 ° C., Example 2: 800 ° C., Example 3: Soaking was performed at 850 ° C. for 30 seconds.

(Examples 4 to 8)
Using an ultra-low carbon steel plate (non-recrystallized steel plate) added with Nb and Ti as a base plate, after degreasing and pickling treatment, electric Mn plating 0.1 to 25 g / m ² under the conditions shown in Table 1 and Table 2 Under the conditions, electric Ni plating 20 g / m ² was performed in this order, and then thermal diffusion treatment was performed. Finally, temper rolling was performed. In the thermal diffusion treatment, soaking was performed for 20 seconds at 780 ° C. in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace.

(Examples 9 to 13)
Using an ultra-low carbon steel sheet (non-recrystallized steel sheet) added with Nb and Ti as a base plate, after degreasing and pickling treatment, the electric Mn plating is 1 g / m ^{2 under} the conditions shown in Table 1, and the electric Ni is under the conditions shown in Table 2. Plating 3 to 50 g / m ² was performed in this order, and then thermal diffusion treatment was performed. Finally, temper rolling was performed. In the thermal diffusion treatment, a soaking process was performed at 800 ° C. for 20 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace.

(Example 14)
Using an ultra-low carbon steel plate (non-recrystallized steel plate) with Nb and Ti composite added as an original plate, after degreasing and pickling treatment, electric Mn plating is performed at 5 g / m ^{2 under} the conditions shown in Table 1, followed by thermal diffusion treatment. went. In the thermal diffusion treatment, soaking was performed at 810 ° C. for 30 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. After the pickling treatment, electric Ni plating 20 g / m ² was performed in a bath in which a commercially available semi-gloss additive 3 g / l was added to the plating bath under the conditions shown in Table 2, and finally temper rolling was performed.

(Example 15)
Using B-added low-carbon Al-killed steel plate (non-recrystallized steel plate) as the original plate, after degreasing and pickling treatment, electrical Mn plating was performed at 7 g / m ^{2 under} the conditions shown in Table 1, followed by thermal diffusion treatment. . In the thermal diffusion treatment, soaking was performed for 20 seconds at 790 ° C. in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. After the pickling treatment, electric Ni plating 20 g / m ² was performed under the conditions shown in Table 2, followed by a post-heat diffusion treatment at 450 ° C. for 8 hours in a batch annealing furnace. Finally, temper rolling was performed.

(Example 16)
Using an ultra-low carbon steel sheet (non-recrystallized steel sheet) added with Nb and Ti as a base plate, after degreasing and pickling treatment, the electric Mn plating is 1 g / m ^{2 under} the conditions shown in Table 1, and the electric Ni is under the conditions shown in Table 2. Plating 5 g / m ² was performed in this order, and then thermal diffusion treatment was performed. The thermal diffusion treatment was soaked at 800 ° C. for 30 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. Thereafter, temper rolling was performed. Thereafter, after degreasing and pickling treatment, electro Ni plating 20 g / m ² was performed in a bath in which a commercially available gloss additive 10 g / l was added to the plating bath under the conditions shown in Table 2.

(Example 17)
It was manufactured under the same conditions as in Example 16 except that a B-added low carbon Al-killed steel plate (non-recrystallized steel plate) was used as the original plate.

(Example 18)
Low carbon Al-killed steel sheet of B added (non-recrystallization steel) as the original plate, degreasing, after pickling, subjected to ^electrical Mn plated 20 g / m 2 under the conditions shown in Table 1, were then thermal diffusion treatment . In the thermal diffusion treatment, soaking was performed at 790 ° C. for 30 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. After the pickling treatment, electric Ni plating 5 g / m ² was performed under the conditions shown in Table 2, and then post-heat diffusion treatment was performed at 550 ° C. for 8 hours in a batch annealing furnace. Finally, temper rolling was performed.

(Example 19)
Using B-added low carbon Al-killed steel plate (non-recrystallized steel plate) as the original plate, after degreasing and pickling treatment, electric Mn plating is performed at 20 g / m ^{2 under} the conditions shown in Table 1, and electric Ni plating is performed under the conditions shown in Table 2. 10 g / m ² was performed in this order, and then thermal diffusion treatment was performed. The thermal diffusion treatment was soaked at 800 ° C. for 30 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. Thereafter, temper rolling was performed. Further, after the degreasing and pickling treatments, electric Ni plating 5 g / m ² was performed under the conditions shown in Table 2. Thereafter, post-heat diffusion treatment was performed at 450 ° C. for 8 hours in a batch annealing furnace. Finally, temper rolling was performed.

(Example 20)
Manufactured under the same conditions as in Example 19 except that the amount of the initial electric Mn plating was 8 g / m ² .

(Example 21)
Manufactured under the same conditions as in Example 19 except that the second thermal diffusion treatment condition was a treatment at 550 ° C. for 12 hours in a batch annealing furnace.

(Comparative Example 1)
Using an ultra-low carbon steel sheet (non-recrystallized steel sheet) added with Nb and Ti as a base plate, after degreasing and pickling treatment, electro Ni plating 45 g / m ² is performed under the conditions shown in Table 2, and then thermal diffusion treatment is performed. It was. The thermal diffusion treatment was soaked at 800 ° C. for 30 seconds in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. Thereafter, temper rolling was performed.

(Comparative Example 2)
Using an ultra-low carbon steel sheet (recrystallized steel sheet) added with Nb and Ti as a base plate, after degreasing and pickling treatment, electric Mn plating is performed at 5 g / m ^{2 under} the conditions shown in Table 1, and electric Ni plating is performed under the conditions shown in Table 2. 20 g / m ² was performed in this order. Thereafter, temper rolling was performed.

(Comparative Example 3)
Using an ultra-low carbon steel sheet (non-recrystallized steel sheet) added with Nb and Ti as a base, after degreasing and pickling treatment, electric Ni plating 20 g / m ^{2 under} the conditions shown in Table ² , and electric Mn under the conditions shown in Table 1 Plating 5 g / m ² was performed in this order, and then thermal diffusion treatment was performed. The thermal diffusion treatment was soaked for 30 seconds at 780 ° C. in a 5% H ₂ -containing N ₂ atmosphere (dew point −40 ° C.) in a continuous annealing furnace. Thereafter, temper rolling was performed.

(Evaluation methods)
(1) Flat plate corrosion resistance (red rust)
A flat plate sample was subjected to a salt spray test of JISZ2371 for 3 days, and observed for occurrence of red rust (iron rust). Furthermore, even if the salt spray test was performed for 4 days, no red rust was evaluated as ◎.
(2) Flat plate corrosion resistance (discoloration)
After performing 10% elongation processing on the flat plate sample, a salt spray test of JISZ2371 was conducted for 3 days, and the color difference of the sample surface before and after the test was measured with a color colorimeter. In addition, the thing in which red rust was seen in a part of sample surface was evaluated in the part without red rust generation | occurrence | production. When the color difference was repeatedly within the measurement error range (<1), it was evaluated as “◯”, and the color difference was evaluated as “×”. Further, even when the salt spray test was conducted for 4 days, the color difference within the measurement error range (<1) was evaluated as ◎.
(3) Processing corrosion resistance (red rust)
After subjecting the sample to 10% elongation processing, a salt spray test of JISZ2371 was conducted for 3 days, and the occurrence of red rust (iron rust) was observed and evaluated. Furthermore, even if the salt spray test was performed for 4 days, no red rust was evaluated as ◎.
(4) Processing corrosion resistance (discoloration)
After subjecting the sample to 10% elongation processing, a salt spray test of JISZ2371 was conducted for 3 days, and the color difference of the sample surface before and after the test was measured with a color colorimeter. In addition, the thing in which red rust was seen in a part of sample surface was evaluated in the part without red rust generation | occurrence | production. When the color difference was repeatedly within the measurement error range (<1), it was evaluated as “◯”, and the color difference was evaluated as “×”. Further, even when the salt spray test was conducted for 4 days, the color difference within the measurement error range (<1) was evaluated as ◎.
(5) Contact resistance After maintaining at 60 ° C. and 98% RH atmosphere for 10 days, contact resistance was measured with a load of 100 g using an electrical contact simulator CRS-1 manufactured by Yamazaki Seiki Laboratory. Less than 10 mΩ was evaluated as ○, and 10 mΩ or more was evaluated as ×.

  Table 3 shows the plating layer structure, Ni, Mn adhesion amount, and performance evaluation results of each sample. The plating layer structure was determined by elemental analysis in the depth direction from the surface layer by GDS and AES. The amount of Ni and Mn deposited was dissolved by the hydrochloric acid aqueous solution, and the adhesion by ICP analysis. The amount is quantified.

  As can be seen from this table, the examples of the present invention showed good corrosion resistance in a range where the amount of deposited Ni was small. On the other hand, in Comparative Example 1 having no diffusion layer containing Mn, the processing corrosion resistance was greatly inferior to that of the example of the present invention, and red rust caused by pinholes in the Ni layer was conspicuous. Further, in Comparative Example 2 having no diffusion layer, the processing corrosion resistance was greatly inferior to that of the Example of the present invention, and not only red rust was generated but also discoloration caused by corrosion of the Mn layer was conspicuous. Further, in Comparative Example 3 in which the order of Ni plating and Mn plating was changed, discoloration was conspicuous and contact resistance was increased in both evaluations of flat plate corrosion resistance and processing corrosion resistance.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The steel material of the present invention may be widely applicable not only to electric and electronic appliances, container materials typified by battery cans, daily household appliances such as binders, but also members that have not been conventionally applied with Ni plating. It is extremely useful in industry.

It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention. It is a schematic diagram which shows an example of a structure of the highly corrosion-resistant plated steel material of this invention.

Claims (11)

  A highly corrosion-resistant plated steel material having at least one of an Fe—Mn diffusion layer and an Fe—Mn—Ni diffusion layer on a steel base material, and further having a Ni plating layer as a surface layer.   2. The highly corrosion-resistant plating according to claim 1, further comprising a Mn—Ni diffusion layer between the Ni plating layer of the surface layer and the Fe—Mn diffusion layer or the Fe—Mn—Ni diffusion layer. Steel material.   It has at least one of Fe-Mn diffusion layer and Fe-Mn-Ni diffusion layer on the steel base material, and further has Mn-Ni diffusion layer or Fe-Mn-Ni diffusion layer on the surface layer High corrosion-resistant plated steel.   The high corrosion-resistant plated steel material according to claim 3, wherein the Ni concentration in the outermost Mn-Ni diffusion layer or the Fe-Mn-Ni diffusion layer is 60 mass% or more. Wherein the total deposition amount of Ni contained in the plating layer and the diffusion layer is 5 to 40 g / m ^2, a high corrosion resistance plating steel according to claim 1. Wherein the total adhesion amount of Mn contained in the plating layer and the diffusion layer is 0.1 to 20 g / m ^2, a high corrosion resistance plating steel according to any one of claims 1 to 5.   The steel material is subjected to Mn plating and Ni plating in this order, and then subjected to thermal diffusion treatment, and at least one of an Fe—Mn diffusion layer and an Fe—Mn—Ni diffusion layer is provided on the steel material. A method for producing a highly corrosion-resistant plated steel material.   A method for producing a highly corrosion-resistant plated steel material, which comprises subjecting a steel material to Mn plating, then subjecting it to thermal diffusion treatment, and providing an Fe-Mn diffusion layer on the steel material, followed by Ni plating.   The method for producing a highly corrosion-resistant plated steel material according to claim 8, wherein a thermal diffusion treatment is further performed after Ni plating to provide a Mn-Ni diffusion layer.   The steel material is subjected to Mn plating and Ni plating in this order, then subjected to thermal diffusion treatment, and after providing at least one of the Fe-Mn diffusion layer and the Fe-Mn-Ni diffusion layer on the steel material, A method for producing a highly corrosion-resistant plated steel material, characterized by performing Ni plating. The high corrosion-resistant plated steel material according to claim 10, wherein after the Ni plating after the thermal diffusion treatment, a thermal diffusion treatment is further performed to provide a Mn-Ni diffusion layer or a Fe-Mn-Ni diffusion layer. Production method.