JP2002012959A - Al-plated steel sheet with excellent corrosion resistance at the processed part and end face - Google Patents

Abstract

(57) [Problem] To provide an Al-plated steel sheet having improved corrosion resistance from an end face, which is a weak point of a conventional aluminum-plated steel sheet. SOLUTION: In a mass% on a steel sheet surface, Mg: 1 to 15
%, Si: 2 to 15%, Zn: 11 to 25%, Sn: 1
-15%, the balance being a coating layer consisting of Al and inevitable impurities, and Mg ₂ S formed in the plating layer.
A processed part and an Al having excellent end face corrosion resistance, wherein the size of the intermetallic compound such as i is less than 10 μm in the major axis.
System plated steel sheet. [Effect] The present invention is a product in which the corrosion resistance of the plating layer and the corrosion resistance of the end face are remarkably improved as compared with the conventional one, and has a large contribution to work as a product which has a longer life in use and is maintenance free. .

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an exhaust system member for automobiles, a gasoline tank material, a metal building material such as a roof wall, and a household part such as a toaster and a stove. It relates to an Al-based plated steel sheet.

[0002]

2. Description of the Related Art Al-based plated steel sheets have been used in automobile parts, building materials, home electric parts and the like as described above because of their high corrosion resistance, heat resistance, and beautiful appearance. In order to respond to the recent demand for improved corrosion resistance of automobile exhaust system members, the original plating
A number of steel plates containing r or stainless steel which have been subjected to aluminum plating to have high corrosion resistance have been developed (Japanese Patent Application Laid-Open Nos. 61-231152 and 3-27).
No. 7761). When Cr-containing steel or stainless steel is used as the base plate, the corrosion resistance naturally increases, but the production cost increases and the workability tends to deteriorate. Therefore, various studies have been made to add a corrosion resistance improving element to the plating bath.
-20091 and the like disclose the addition of Cr and Mn. However, even in these, it has not yet been possible to completely suppress the generation of red rust in severely bent parts or end faces.

On the other hand, recently, Pb of an automobile fuel tank has been
Freedom is being studied, and the use of aluminum-plated steel sheets for this purpose is also advancing. The problem at this time is a high balance between corrosion resistance, workability, and weldability. In general, in a surface-treated steel sheet, as the amount of plating increases, the corrosion resistance naturally increases, but the workability and weldability tend to decrease. The weldability at this time means continuous workability, and Al reacts easily with Cu of the electrode material. Therefore, when the amount of adhesion increases, the amount of reaction with the electrode increases, and the life of the electrode decreases. Also in press working, an increase in the amount of adhesion tends to cause damage, peeling, and the like of the plating layer.

[0004] In order to make these characteristics compatible,
Again, many inventions have been made (JP-A-10-463).
No. 58, etc.), it is difficult to say that corrosion resistance, weldability, and workability can be completely compatible. In addition, aluminum plating is extremely excellent in corrosion resistance especially in a dry / wet environment.
In a constantly wet environment, dissolution tends to proceed easily. In particular, the plating may be sacrificed to prevent corrosion of the steel plate and dissolve preferentially on the side wall portion where processing is severe or on the flange end surface portion where coating is difficult, and red rust may be generated in a short period of time.

[0005] Conventional surface-treated steel sheets for building materials include:
Although Zn-plated steel sheets have been mainly used, recently, from the demand for further improvement of corrosion resistance and design, Al-Zn
The amount of use of a galvanized steel sheet or an Al—Si-plated steel sheet is also increasing. In an Al-Zn alloy-plated steel sheet, as the addition amount of Al increases, the corrosion resistance is excellent, but the sacrificial corrosion protection action tends to be weak. After several months from use, generation of red rust is observed on the end face or severely bent part. Can be

Further, in the case of an aluminum-plated steel sheet having an excellent corrosion resistance of a plating layer, under normal atmospheric conditions, there is almost no sacrificial corrosion-preventing action of the base steel, and red rust is generated on the end surface within a few days, so that repair painting after construction is required. It is necessary and the work becomes complicated. Alternatively, if the repair coating is insufficient, there is a problem that red rust is generated from the end face and the appearance is impaired. In order to cope with this problem of the aluminum-plated steel sheet, the present inventors have disclosed a technique for suppressing generation of red rust from a processed portion in Japanese Patent Application Laid-Open No. Hei 6-330274. However, although this can suppress the generation of red rust from the processed portion, the problem of the generation of red rust from the end face still remains.

[0007]

Therefore, in the present invention, by adding Mg and Zn which contribute to the corrosion resistance to the aluminum plating layer, the corrosion resistance of the plating layer and the end face is remarkably improved compared with the conventional one. An object of the present invention is to provide an Al-based plated steel sheet which can secure workability and post-process corrosion resistance, thereby exhibiting sufficient corrosion resistance with a low adhesion amount.

[0008]

Means for Solving the Problems The present inventors have studied in detail the effects of the elements added to the plating bath on the corrosion resistance of the Al-based plating layer and the corrosion resistance of the processed portion and the end face.
The present inventors have found that by adding i, Mg, Zn, and Sn in appropriate amounts, the plating surface is excellent in corrosion resistance and the generation of red rust on the processed portion and the end face can be suppressed, and the present invention has been completed.

Hereinafter, the present invention will be described in detail. JP 5
In JP-A-6-127762, the present applicants have already
A method for producing an aluminized steel sheet containing i and Mg is disclosed. The present inventors have studied the plating structure when Si, Mg, Zn, and Sn are added, the corrosion resistance at that time, and the like in more detail, and have obtained the following findings. That is, S
by adding i, Mg, Zn in combination, or
By containing Sn in addition to i, Mg, Zn, M
g and Zn dissolve in an air environment, a wet environment, or a salt damage environment to form a dense Mg-based and / or Mg-Zn-based coating on the exposed surface of the ground iron or the plating surface, and the sacrificial corrosion protection effect of Zn is added. It has been found that the corrosion resistance of the processed portion and the end face is remarkably improved, and the corrosion resistance of the plating layer surface is also excellent.

Further, Mg ₂ Si, MgZn is contained in the plating layer.
₂ , the corrosion resistance can be further improved by generating an intermetallic compound of Mg ₂ Sn. Since this intermetallic compound becomes a lump and is preferentially dissolved when exposed to a corrosive environment, it has excellent Mg supply power. However, if the size exceeds a certain size, caution is required because the intermetallic compound is hard, so that workability is reduced and corrosion from the processed portion may be accelerated.

The Mg ₂ Si, MgZn ₂ , Mg ₂ Sn
It is effective to control the cooling rate in order to crystallize a desired amount in a desired size. For example, rapid cooling after plating is preferable. According to the invention, Si, Mg,
By adding Zn and Sn, and by appropriately controlling the addition amount thereof, it becomes possible to obtain an Al-based plated steel sheet having dramatically improved corrosion resistance. Depending on the application, simplification of the post-treatment film and the lubricating film required can be achieved, and the effect of improving weldability or workability also increases.

The gist of the present invention is as follows. (1) On the surface of the steel sheet, in mass%, Mg: 1 to 15%, S
i: 2 to 15%, Zn: 11 to 25%, the balance having a coating layer composed of Al and unavoidable impurities, and a metal such as a Mg ₂ Si phase and a MgZn ₂ phase existing in the plating layer An Al-based plated steel sheet having excellent corrosion resistance at the processed portion and at the end face, wherein the size of the intermetallic compound is less than 10 μm in the major axis.

(2) On the surface of the steel sheet, Mg: 1
-15%, Si: 2-15%, Zn: 11-25%, and at least one of Ca, Be, Sr, and Ba in an amount of 0.02-5%, with the balance being Al and unavoidable impurities. Having a coating layer of
An Al-based plated steel sheet excellent in corrosion resistance at a processed portion and an end face, wherein the size of an intermetallic compound such as a g ₂ Si phase and a MgZn ₂ phase is less than 10 μm in a major axis.

(3) On the surface of the steel sheet, Mg: 1
-15%, Si: 2-15%, Zn: 11-25%, S
n: containing 1% to 15%, has a coating layer and the balance of Al and unavoidable impurities, and Mg ₂ Si phase existing in the plating layer, MgZn ₂ phase, intermetallic compounds such as Mg ₂ Sn phase An Al-based plated steel sheet having excellent corrosion resistance in a processed portion and an end face, wherein the length of the steel sheet is less than 10 μm in a major axis.

(4) On the surface of the steel sheet, Mg: 1
-15%, Si: 2-15%, Zn: 11-25%, S
n: In addition to 1 to 15%, at least one of Ca, Be, Sr, and Ba is contained in an amount of 0.02 to 5%, and the balance has a coating layer composed of Al and inevitable impurities, and in the plating layer Mg ₂ Si phase, MgZn ₂ phase, Mg ₂ S
A having excellent corrosion resistance in the processed portion and the end face, wherein the size of the intermetallic compound such as the n-phase is less than 10 μm in the major axis.
l-plated steel sheet.

(5) 5 μm thickness at the interface between the plating phase and the steel sheet
m or less Al-Fe-Si alloy layer or Al-Fe
The Al-plated steel sheet having excellent corrosion resistance in the processed portion and the end face according to any one of (1) to (4), further including a -Si-Mg-based alloy layer. (6) The Al-plated steel sheet excellent in corrosion resistance of the processed portion and the end face according to the above (1) to (5), which has a post-treatment film on the surface of the plating layer.

(7) The surface of the plating layer or (6)
(1) to (6), wherein the Al-plated steel sheet is excellent in the corrosion resistance of the processed portion and the end face, wherein the Al-coated steel sheet has a delaminated or non-delaminated lubricating film on the post-treated film described in (1). (8) The adhesion amount of the Al-based plating layer is 20 to 20 per one side
(1) to (7), wherein the content is 0 g / m ^2.
And an Al-based plated steel sheet having excellent corrosion resistance at the processed portion and end face.

Next, the reasons for limitation of the present invention will be described.
You. First, the limitation of Al-based coating layer (hereinafter abbreviated as plating layer)
Explain why. Plating layer: Si: 2 to 15%, Mg: 1
-15%, Zn: 11-25%,
Sn: 1 to 15%, one of Ca, Be, Sr and Ba
0.02 to 5% of the above, the balance being Al and inevitable
It shall consist of impurities. Mg, Zn, Si, Sn
Mg in the plating layer_TwoSi, MgZn
_Two, Mg_TwoThe Sn phase is formed, and the corrosion resistance is greatly improved. I
Therefore, complex addition of Si, Mg, Zn and Sn
Is desirable.

[0019] Although Si is added for the purpose of normal alloy layer growth suppression in Al-based plated steel sheet, the present invention Mg ₂
Used for crystallization of Si phase. If the amount of Si is too small, the crystallization effect is lost and the effect of improving the corrosion resistance is not exhibited. On the other hand, if the amount is too large, coarse Si primary crystals are formed, impairing the corrosion resistance and workability. Therefore, the amount of Si added is limited to 2 to 15%.

When Mg is added in an amount of 1% or more, the effect of improving the corrosion resistance is exhibited, and 5 to 6% has the maximum effect. Although Mg is an element that is extremely easily oxidized, even if such an amount is added to the aluminum plating bath, generation of dross does not particularly increase. However, as the amount of Mg added increases, the viscosity of the bath gradually increases, and the operability deteriorates.
Also, its effect on corrosion resistance tends to saturate.
The upper limit of g is set to 15%. The addition of Zn is 11%.
The effect of improving the corrosion resistance is exhibited as described above. However, when the addition exceeds 25%, the sacrificial corrosion prevention effect of Zn becomes dominant, and Mg or Mg is added.
-A dense and stable Zn-based film is hardly formed, and the corrosion resistance of the plating layer is reduced. Therefore, the amount of Zn added is 11
To 25%.

Sn, unlike Si, does not have the effect of suppressing the growth of the alloy layer and cannot be a substitute for Si. However, like Si, it forms Mg and an intermetallic compound, Mg ₂ Sn, to improve the corrosion resistance. Therefore, it may be contained in the plating layer together with Si. In particular, when the amount of Si is limited to suppress the coarse Si crystal, it is effective to secure an intermetallic compound necessary for corrosion resistance. Sn content is 1
The lower limit is limited in consideration of the effect on corrosion resistance and the upper limit in consideration of adverse effects on operability such as bath temperature and viscosity.

In the present invention, Mg ₂ S is contained in the plating layer.
By adopting a structure in which an intermetallic compound of i, MgZn ₂ , and Mg ₂ Sn is dispersed, the corrosion resistance can be further improved. As described above, these crystals dissolve in the use environment to form a Mg or Mg-Zn-based protective film, thereby protecting the plating layer itself and the exposed portion of the base iron.
The greater the amount, the more the effect of improving corrosion resistance. However, if this size is too large, it adversely affects the workability and as a result lowers the corrosion resistance of the processed portion, so that the state in the plating layer may be finely dispersed or massive. When the size was observed from the cross section, the major axis was 10
It was less than μm. The smaller the size, the better the workability. As for the size of the intermetallic compound, the structure is observed by polishing the cross section at an inclination of 5 degrees.

Further, particularly in the production by hot-dip plating, a large amount of Mg is contained, so that an oxide film of Mg is formed on the surface in the process of wiping and cooling after plating. Since only the surface is bound and the inside is still in a molten state, wrinkles occur on the surface due to the influence of gravity, cooling gas and the like. The size, spacing, etc. of the wrinkles vary depending on the manufacturing conditions, but due to the wrinkles, the appearance becomes uneven and the commercial value is reduced. As means for suppressing such wrinkles, Ca, Be, Sr, and Ba are particularly effective. When the amount of addition is 0.02% or more, the effect of suppressing wrinkles is exhibited. Similar effects can be obtained even if they are added in combination.
On the other hand, the upper limit is set to 5% from the viewpoint of increasing the bath temperature and lowering the workability of the plating layer.

These elements are Si in the plating layer.
Although a compound with Al can be produced, its form is not particularly limited because it does not affect the suppression of wrinkles. The plating layer may contain Fe as an unavoidable impurity in addition to these elements, but the amount is usually 1% or less, and the influence on the plating structure is relatively small. Furthermore, Cr, Mn,
It is also possible to add a small amount of an element such as Ti.

In the present invention, the method for producing an Al-based plated steel sheet is not particularly limited.
An electroplating method from a non-aqueous solvent, a vapor deposition method, a clad method, and the like can be applied. Currently, the most industrially widespread is a hot-dip Al-coated steel sheet. At this time, an alloy layer composed of an intermetallic compound is generated at the interface between the plating layer and the ground iron. When an Al—Si—Mg—Zn-based plated steel sheet is manufactured by the melting method, an alloy layer is naturally formed, but the composition of the alloy layer at this time is A
It is an l-Si-Fe system. However, when the amount of Mg increases, A
Formation of l-Fe-Si-Mg intermetallic compounds is also observed. The thickness of the alloy layer is desirably 5 μm or less. This is because the alloy layer is hard and brittle, and if the alloy layer is thick, the workability of the steel sheet is greatly impaired. By adding Mg to the plating bath, an effect of reducing the thickness of the alloy layer can be obtained, and an alloy layer of 2 μm or less can be obtained.

Next, the steel composition of the base material will be described. There is no particular limitation on the steel composition, and any steel type has an effect of improving corrosion resistance. As steel types, in addition to IF steel, Al-k steel, Cr-containing steel, stainless steel, and high tensile steel to which Ti, Nb, B, etc. are added, Ti-added steel for heat resistance, and free-N addition for alloying suppression effect It is also possible to use steel or the like. Al-k or stainless steel for construction materials, Ti-IF or Ti-added steel for exhaust systems, Al-k or free-N-added steel for home appliances, fuel tanks It is preferable to use a B-added IF steel.

In the present invention, the post-treatment of plating is not particularly limited, but a chemical conversion treatment such as chromate or phosphate treatment can be performed, and post-treatment containing a resin may be used. As the chemical conversion treatment, phosphoric acid, silica, or the like can be contained, and an Mg-based compound may be added. As the resin type, for example, all treatments including general-purpose resins such as acrylic, polyethylene, polyester, melamine, epoxy, urethane, and fluorine resins are possible. Recently, various post-treatments that do not use Cr are being developed, but it is naturally possible to apply these.

Depending on the application, the surface layer of this treatment may be further coated with an organic resin. As the organic resin, there is a non-film removal type resin film or a film removal type resin film such as a clear treatment utilizing the appearance of aluminum, a color treatment containing a pigment, or a treatment for improving weldability. General-purpose processing such as acrylic resin, polyethylene resin, polyester resin, melamine resin, epoxy resin, urethane resin, and fluorine resin can be used. The film thickness is not particularly limited, and a normal process of about 0.5 to 20 μm can be performed. In addition to this, post-plating post-treatments such as zero spangle treatment, annealing, and temper rolling may be applied, but these are not particularly limited and can be applied.

Finally, the reason for limiting the amount of plating will be described. In the present invention, the total coating amount of the Al-based coating layer and the intermetallic compound layer (hereinafter, referred to as the plating adhesion amount) is set to 20 per one side.
It is desirable to set it to 200 g / m ² . In building materials, the life of the plating layer and the generation of red rust from the processed end face tend to be suppressed by increasing the amount of adhesion. The present invention realizes increased corrosion resistance, end face, and processed portion corrosion resistance, and exhibits sufficient performance even with a lower basis weight than the conventional one, but the effect of improving the corrosion resistance is naturally obtained as the amount of adhesion increases. If the amount is less than 20 g / m ^{2 on} one side, there is a little concern in terms of long-term durability, and if the amount is too large, there is a concern that workability may be impaired. Therefore, the preferable amount of adhesion is ²⁰ to 200 g / m ² per side.

Next, the present invention will be described in more detail with reference to examples.

(Example 1) Steel having the components shown in Table 1 was melted by a normal converter-vacuum degassing process to obtain a steel slab, which was then subjected to hot rolling and cold rolling under normal conditions. Thus, a cold-rolled steel sheet (sheet thickness 0.8 mm) was obtained. Using this as a material, a hot-dip Al-based plated steel sheet was obtained. For the hot-dip Al plating, a non-oxidizing furnace-reducing furnace type line was used, and annealing was also performed in this line. The annealing temperature was 800 to 850 ° C. As the plating bath composition, Al-Si-Mg-Zn was mainly used, and a part in which Sn was added to Al-Si-Mg-Zn was also examined. This composition was variously changed, and the temperature of the intruding plate and the cooling rate after plating were controlled to manufacture the alloy layer with a lower thickness. The bath temperature was set to the melting point + 60 ° C. After plating, the amount of plating was adjusted by a gas wiping method. The plating appearance was good with no plating or the like. In addition, as a post-treatment, the silane coupling agent-based non-chromate film is
It was treated at 100 mg / m ² per side in terms of O ₂ and temper rolled at 0.5%. The performance of the hot-dip Al-coated steel sheet manufactured in this manner was evaluated by the following method.

[0031]

[Table 1]

[0032] (1) plating layer composition, the alloy layer thickness analysis methods plated layer composition: 3% NaOH + 1% AlCl 3 · 6H
Only the plating layer was peeled off by constant current electrolytic peeling in ₂ O. Since Mg is insoluble in an alkaline solution, after electrolytic stripping, it was further treated with 20% nitric acid and mixed with an electrolytic stripping solution to obtain a plating layer composition analysis solution. The analysis of each element was performed by ICP. When analyzing after chromate treatment,
It is necessary to reduce the influence of Cr in the chromate by lightly polishing the surface. Plating layer composition: 5 degree inclined polishing of the plating layer cross section
Observation of plating structure by optical microscope (200 to 500 times)
Was done. The maximum major axis of the intermetallic compound present in the plating layer in a plating 1 mm width visual field was measured at any five locations. Alloy layer thickness: The alloy layer thickness was measured from a 400-fold cross-sectional micrograph.

(2) Evaluation of Corrosion Resistance Corrosion Resistance to Salt Damage JIS Z 23 for a sample having a size of 70 × 150 mm
The salt spray test according to No. 71 was performed for 30 days, and the corrosion products were peeled off and the corrosion weight loss was measured. The indication of the corrosion weight loss is a value for one side of the plating. (Evaluation criteria) ◎: corrosion weight loss 5 g / m ² or less ○: less than corrosion loss 10g / m ² △: Corrosion weight loss 10~25g / m ² ×: corrosion weight loss: 25 g / m ² greater

Corrosion resistance after processing After performing bending work equivalent to 3t (t: plate thickness) using a roll former, a salt spray test in accordance with JIS Z 2371 was performed for 30 days, and the corrosion state near the processed portion was observed. . (Evaluation criteria) ：: No red rust generated ○: Red rust generation rate 5% or less △: Red rust generation rate 5 to 30% ×: Red rust generation rate exceeds 30%

Outdoor Exposure Test An outdoor exposure test was performed on a sample having a size of 50 × 200 mm at 30 ° on the south side. Red rust occurrence rate from the end face after 3 months,
The surface discoloration was observed. (Evaluation criteria) ：: Red rust occurrence rate from the end face is less than 30% Δ: Red rust occurrence rate from the end face is 30 to 80% ×: Red rust occurrence rate from the end face is more than 80%

(3) Workability Using a hydraulic forming tester, cup forming was performed at a drawing ratio of 2.25 using a cylindrical punch having a diameter of 50 mm. The test was performed by applying oil, and the wrinkle pressure was 500 kg. The evaluation of workability was based on the following index. (Evaluation criteria) ○: No abnormality △: Cracking of plating ×: Peeling of plating

[0037]

[Table 2]

[0038]

[Table 3]

Comparative Example No. In the case where Mg is not contained as in the case of 13, the corrosion resistance tends to be inferior in a severe environment. On the other hand, when the amount of Si is small, the alloy layer grows and the workability is poor. Also, in Comparative Example No. In the case where Zn is not contained as in 15 and 16, red rust is generated from the end face, and Zn
If the amount is too large, swelling of the coating film is promoted due to dissolution of Zn, and the corrosion resistance tends to decrease. Also, in the present invention example,
No. As in 4, even if there is too much Mg, the corrosion resistance tends to decrease, and Mg is preferably about 4 to 9% from the viewpoint of corrosion resistance. In addition, the present invention example No. Even with a large amount of Si as in No. 7, corrosion resistance and workability tend to decrease. Also, in Comparative Example No. As shown in Fig. 15, the size of the intermetallic compound is
When it is more than m, workability tends to decrease.
When the amounts of Mg, Si, Zn, and Sn are in appropriate ranges, extremely excellent corrosion resistance and workability are exhibited.

(Example 2) The composition and operating conditions of the plating bath were fixed, and the effect of adding Ca, Be, Sr, and Ba was investigated. Plating bath composition is Al-8% Si-6% Mg-15%
Zn-1.5% Fe and Al-8% Si-6% Mg-
20% Zn-3% Sn-0.5% Fe, 80 g / m ^{2 of} coating weight on both sides, post-treatment of non-chromate film based on silane coupling agent based on SiO ₂ , 1 per side
It was treated with 00 mg / m ² . Evaluation items are basically Example 1.
And the presence or absence of visual wrinkles was added as an appearance evaluation. Table 4 shows the results of the evaluation. The effect of suppressing wrinkles was observed with any metal addition, but Sr tends to slightly reduce the corrosion resistance.

[0041]

[Table 4]

(Example 3) The composition of the plating bath and the operating conditions were fixed, and the influence of the original plating plate was investigated. The plating bath composition is Al-8% Si-6% Mg-15% Zn-1.5% Fe
Assuming -0.1% Ca, the coating weight on both sides is 80 g / m
^{(2) The} post-treatment was a non-chromate treatment using a silane coupling agent, and the amount of adhesion was 100 mg / m ^{2 in} terms of SiO ₂ . Evaluation items and methods are the same as those in the first embodiment. At this time, the composition of the plating layer was substantially Si: 8.2%, M
g: 6.1%, Zn: 14.5%, Fe: 0.5%, C
a: 0.09% and the alloy layer thickness: 1.8 to 2.8 μm were obtained. The maximum major axis of the intermetallic compound in the plating layer was 8 μm. Table 5 shows the steel types used.
Table 6 summarizes the evaluation results at that time. Excellent characteristics were obtained regardless of the type of steel used.

[0043]

[Table 5]

[0044]

[Table 6]

[0045]

According to the present invention, there is provided a hot-dip aluminized steel sheet which is significantly more excellent in corrosion resistance of a plating layer and corrosion resistance of an end face than conventional ones. The application of aluminum-plated steel sheet has been started from conventional automobile exhaust system members, heat appliances, roof walls, etc., and recently it has also started to be applied to automobile fuel tanks. It is expected to be maintenance-free, and will greatly contribute to work.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C23C 28/00 C23C 28/00 C (72) Inventor Jun Maki 1-1-1 Tobata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture No. Nippon Steel Corporation Yawata Works (72) Inventor Teruaki Izaki 1-1, Tobata-cho, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture Nippon Steel Corporation Yawata Works (72) Inventor Shunji Sakamoto Kitakyushu, Fukuoka Prefecture No. 1-1 Hibata-cho, Tochihata-ku, Ichiba New Nippon Steel Corporation Yawata Works F-term (reference) 4K026 AA09 AA13 AA22 BA02 BB08 CA27 4K027 AA02 AA22 AB05 AB28 AB32 AB48 AC52 AC82 AC87 4K044 AA02 AB02 BA10 BA14 BB03 BC02 BC05 CA11 CA16 CA53

Claims (8)

[Claims] 1. The composition according to claim 1, wherein Mg: 1 to 1
5%, Si: 2 to 15%, Zn: 11 to 25%, the balance having a coating layer composed of Al and unavoidable impurities, and an Mg ₂ Si phase, MgZ present in the plating layer
An Al-based plated steel sheet having excellent corrosion resistance at a processed portion and at an end face, wherein a size of an intermetallic compound such as an n ₂ phase is less than 10 μm in a major axis. 2. The composition according to claim 1, wherein Mg: 1 to 1 in mass% on the surface of the steel sheet.
5%, Si: 2 to 15%, Zn: 11 to 25%,
At least one of Ca, Be, Sr, and Ba is set to 0.0
Mg ₂ S containing 2 to 5%, the balance having a coating layer composed of Al and unavoidable impurities, and existing in the plating layer
An Al-based plated steel sheet excellent in corrosion resistance of a processed portion and an end face, wherein a size of an intermetallic compound such as an i-phase and a MgZn ₂ phase is less than 10 μm in a major axis. 3. The composition according to claim 1, wherein Mg: 1 to 1 in mass% on the surface of the steel sheet.
5%, Si: 2 to 15%, Zn: 11 to 25%, Sn:
1 to 15%, the balance having a coating layer composed of Al and unavoidable impurities, and Mg present in the plating layer.
₂ Si phase, MgZn ₂ phase, Al-based plated steel sheet excellent in processability portion and end corrosion resistance, wherein the size of intermetallic compounds such as Mg ₂ Sn phase is less than the major diameter 10 [mu] m. 4. The composition according to claim 1, wherein Mg: 1 to 1 on a steel sheet surface in mass%.
5%, Si: 2 to 15%, Zn: 11 to 25%, Sn:
A coating layer containing at least one of Ca, Be, Sr, and Ba in an amount of 0.02 to 5% in addition to 1 to 15%, and the balance having Al and unavoidable impurities, and being present in the plating layer An Al-plated steel sheet excellent in corrosion resistance of a processed portion and an end face, wherein a size of an intermetallic compound such as a Mg ₂ Si phase, a MgZn ₂ phase, and a Mg ₂ Sn phase is less than 10 μm in a major axis. 5. An Al—Fe—Si alloy layer or Al—Fe—S layer having a thickness of 5 μm or less at an interface between a plating phase and a steel sheet.
An i-Mg based alloy layer is provided.
4. An Al-plated steel sheet having excellent corrosion resistance in the processed portion and the end face according to 4. 6. The Al-plated steel sheet according to claim 1, further comprising a post-treated film on the surface of the plating layer, wherein the Al-based steel sheet has excellent corrosion resistance in the processed portion and the end face. 7. A processed part according to claim 1, further comprising a delaminated or non-delaminated lubricating film on the surface of the plating layer or on the post-treated film according to claim 6. Al-plated steel sheet with excellent edge corrosion resistance. 8. The adhesion amount of the Al-based plating layer is 2 per one side.
The amount is from 0 to 200 g / m ² .
An Al-plated steel sheet having excellent corrosion resistance in the processed portion and the end face according to 7.