KR101106010B1 - Method for manufacturing ferritic stainless steel having a corrosion-resisting layer - Google Patents

Abstract

The present invention relates to a ferritic stainless steel wire having a high corrosion resistance layer and a manufacturing method thereof.
The ferritic stainless steel wire 100 having a corrosion resistant layer according to the present invention comprises a raw material 120 made of ferritic stainless steel and a corrosion resistant layer 140 plated outside the raw material 120. The corrosion resistant layer 140 is characterized in that the nickel plated layer 130 plated on the outer surface of the raw material 120 is formed by diffusion into the raw material 120 by heat. In addition, the method for producing a ferritic stainless steel wire having a corrosion resistant layer according to the present invention, the material preparation step (S100) for preparing the raw material 120 made of ferritic stainless steel, and formed on the outer surface of the raw material 120 Surface defect removal step (S200) to planarize the surface by removing the surface defect 122, and nickel plating step of forming a nickel plating layer 130 on the outer surface of the raw material 120 from which the surface defect 122 is removed (S300) And a diffusion heat treatment step (S400) of forming the corrosion resistant layer 140 by heat-treating and diffusing the raw material 120 and the nickel plating layer 130. According to the present invention configured as described above, there is an advantage that the steel wire with improved corrosion resistance can be manufactured at low cost.

Description

Method for manufacturing ferritic stainless steel wire having a corrosion resistant layer {Method for manufacturing ferritic stainless steel having a corrosion-resisting layer}

The present invention relates to a method for producing a ferritic stainless steel wire having a high corrosion resistance layer.

Stainless steel wire and its processed products can be classified into industrial products, springs, fences, straight lines, weaving, cold presses, free cutting, general processing, etc. It is used in electronics, electricity, precision machinery, office equipment and medical equipment, and in general consumer products, it is widely used in our lives such as kitchen, interior, insect screen, leisure, and decoration.

In general, stainless steel wire is divided into austenitic, ferritic, and martensitic stainless steel. Austenitic stainless steel wire is most widely used because of its excellent corrosion resistance and formability, but has lower hardness and strength than other stainless steel wires.

On the other hand, ferritic stainless steel wire has high hardness and excellent high temperature oxidation resistance and electrical conductivity, while corrosion resistance is significantly lower than that of austenitic stainless steel wire.

Although martensitic stainless steel wire is used for high stress and high stress, its corrosion resistance is lower than that of austenitic stainless steel wire.

These various stainless steel wires have their strengths and weaknesses. Generally, the mechanical properties are excellent in ferritic stainless steel wires and austenitic stainless steel wires in terms of corrosion resistance.

Meanwhile, the domestic stainless steel wire industry has gained a global competitive edge in terms of capacity investment through facility investments, but since 2002, raw material prices have risen due to the depletion of raw materials due to changes in the industrial environment and the enormous encroachment of resources by lagging countries such as China and India. In the aftermath, prices are struggling in the global market.

In particular, the price is very unstable, such as the price soared by the encroachment and speculative forces of nickel, the main alloying element of austenitic stainless steel.

As a result, the prices of austenitic stainless steel wires have soared, leading to an increase in the price of domestically produced products, leading to a drop in price competitiveness.

Therefore, in order to secure a competitive advantage in the global market, it is urgent to create high value using low cost raw materials and to add value by diversifying its applicability by providing high quality and high functionality.

Korean Patent Office Registration No. 0210824 "Stainless Steel Wire and Manufacturing Method" discloses a technique of forming a sulfate coating on the outer surface of a stainless steel wire to improve lubricity during processing and to improve production efficiency.

However, this conventional technology has a problem that the productivity is reduced because the steel wire can be manufactured through a number of processes. In addition, conventionally, a technique having the purpose of simultaneously improving the lubricity and corrosion resistance of a stainless steel wire by applying a nickel plating layer and a diffusion heat treatment process has not been published.

In addition, the Republic of Korea Patent Office Patent No. 0218230 nickel-plated stainless steel wire manufacturing method for spring "has been published a technique for plating nickel to give fresh surface lubricity.

However, this conventional technique simply improves the lubricity by using the lubricity of nickel in the drawing process, and increases the corrosion resistance of the stainless steel by thickening the nickel plating, and therefore, the principle of the interface between the raw materials exists to improve the adhesion and the corrosion resistance is fundamental. Different, and its effect and economy are also quite low.

An object of the present invention is to form a nickel-plated layer on the surface of the ferritic stainless steel wire having a low nickel content and low cost, and induces element diffusion by heat treatment so as to correspond to the austenitic stainless steel or nickel-based high corrosion resistance alloy only on the surface portion. It is to provide a method for producing a ferritic stainless steel wire having a corrosion resistant layer to minimize the input of nickel while giving corrosion resistance to the ferritic stainless steel wire by inducing transformation.

Another object of the present invention is to provide a method for producing a ferritic stainless steel wire having a corrosion resistant layer that is excellent in hardness, conductivity, and magnetic properties, and is applicable to various applications.

Method for producing a ferritic stainless steel wire having a corrosion-resistant layer according to the present invention, the material preparation step of preparing a raw material consisting of a ferritic stainless steel, and the surface defect removal step of removing the surface defects formed in the inner surface of the raw material And a nickel plating step of forming a nickel plating layer on the outer surface of the raw material from which the surface defects have been removed, and a diffusion heat treatment step of forming a corrosion resistant layer by heat-treating the raw material and the nickel plating layer to diffuse the nickel plating layer. do.

The surface defect removal step is characterized in that any one of an electropolishing process and a low melting alloy plating process is applied.

The electropolishing process is characterized in that it is carried out for more than 5 minutes at a current density of 30 A / dm ² or more in a solution of the concentration ratio of phosphoric acid and sulfuric acid 9: 1.

The low melting alloy plating process is characterized in that the plating of Ni-P or Ni-B on the outer surface of the raw material.

The nickel plating step is characterized in that the nickel plating layer on the outer surface of the raw material to a thickness of 0.1㎛ to 2% of the raw material wire diameter.

The diffusion heat treatment step is characterized in that carried out for 30 seconds to 10 minutes in an inert or reducing atmosphere of 500 to 900 ℃.

After the diffusion heat treatment step, characterized in that the wire diameter adjustment step for adjusting the outer diameter size of the manufactured ferritic stainless steel wire.

As described in detail above, in the method for producing a ferritic stainless steel wire having a corrosion resistant layer according to the present invention, a nickel content is plated on a surface of an inexpensive ferritic stainless steel wire with a low nickel content to form a nickel plated layer, Elemental diffusion was induced by heat treatment.

Therefore, since surface defects that may cause poor plating and corrosion resistance are eliminated, corrosion resistance is equivalent to that of austenitic stainless steel or nickel-based high corrosion-resistant alloy, and the amount of expensive nickel is minimized to minimize input of expensive nickel. The manufacturing cost is reduced.

In addition, the hardness is improved, and the feature of the ferritic stainless steel has the advantage that can be applied to various applications because it can additionally have electrical conductivity and magnetic properties.

1 is a schematic view showing the configuration of a ferritic stainless steel wire having a corrosion resistant layer according to the present invention.
2 is a process flow chart showing a method for producing a ferritic stainless steel wire having a corrosion resistant layer according to the present invention.
Figure 3 is a SEM photograph showing the surface and cross-section of the raw material before the nickel plated layer formed in a ferritic stainless steel wire having a corrosion resistant layer according to the present invention
Figure 4 is a SEM photograph showing the surface and the cross section of the raw material after the nickel plated layer formed in a ferritic stainless steel wire having a nickel plated layer according to the present invention.
Figure 5 is a SEM photograph showing the surface and cross section of the corrosion resistant layer in a ferritic stainless steel wire having a nickel plated layer according to the present invention.
6 is an experimental data comparing the distribution of components before and after heat treatment of a ferritic stainless steel wire having a nickel plated layer according to the present invention.
7 is a sample photograph for the adhesion test of the ferritic stainless steel wire having a nickel plated layer according to the present invention.
Figure 8 is a table showing the adhesion and corrosion resistance test results of the sample that is not subjected to the surface defect removal step of a step in the method for producing a ferritic stainless steel wire having a nickel plating layer according to the present invention.
Figure 9 is a photograph showing the surface after the electropolishing process in the surface defect removal step of one step of the method of manufacturing a ferritic stainless steel wire having a nickel plating layer according to the present invention.
10 is a photograph showing an enlarged surface state of the current density change in the surface defect removal step of one step of the method for manufacturing a ferritic stainless steel wire having a nickel plating layer according to the present invention.
Figure 11 is a photograph showing a cross-section before and after the application of the electropolishing process in the surface defect removal step of one step of the method of manufacturing a ferritic stainless steel wire having a nickel plating layer according to the present invention.
12 is a table showing the corrosion resistance test results of the sample subjected to the electropolishing process during the surface defect removal step, which is one step in the method for producing a ferritic stainless steel wire having a nickel plating layer according to the present invention.
13 is a table showing the corrosion resistance test results of the sample to which the low-melting point alloy plating was applied during the surface defect removal step which is one step in the method of manufacturing a ferritic stainless steel wire having a nickel plating layer according to the present invention.

Hereinafter, a configuration of a ferritic stainless steel wire (hereinafter referred to as a “ferritic stainless steel wire”) having a nickel plating layer according to the present invention will be described with reference to the accompanying FIG. 1.

As shown in the figure, the ferritic stainless steel wire 100 is formed so that the corrosion-resistant layer 140 is formed on the ferritic stainless steel wire so that the content of expensive nickel (Ni) is 0.08 to 4.6% by weight.

That is, the ferritic stainless steel wire 100 is a raw material 120 composed of a ferritic stainless steel located therein, and a high content diffused into the raw material 120 after being coated on the outer surface of the raw material 120 It is configured to include a corrosion resistant layer 140.

The corrosion resistant layer 140 has a thickness of 0.1 μm or more, and preferably has a thickness of 2% or less with respect to the outer diameter of the raw material 120.

In an embodiment of the present invention, nickel (Ni) was used as a material constituting the corrosion resistant layer 140, and SUS430 was applied to the raw material 120.

Hereinafter, a method of manufacturing a ferritic stainless steel wire will be described with reference to FIG. 2.

2 is a process flowchart showing a method of manufacturing a ferritic stainless steel wire having a corrosion resistant layer according to the present invention.

As shown in the drawing, the process of manufacturing the ferritic stainless steel wire, the material preparation step (S100) for preparing the raw material 120 composed of ferritic stainless steel, and surface defects 122 formed on the outer surface of the raw material 120 ) And a nickel plating step (S300) of forming a nickel plating layer 130 on the outer surface of the raw material 120 from which the surface defects 122 are removed, and the raw material ( 120 and the nickel plating layer 130 is heat-diffused to form a diffusion heat treatment step (S400) to form a corrosion-resistant layer 140.

The material preparation step (S100) is a process of preparing the raw material 120, which is a ferritic stainless steel wire, the raw material 120 is manufactured through the drawing is very large surface roughness by friction with the drawing dies.

That is, when looking at the surface and the cross-section of the raw material 120 (430 stainless steel wire diameter 1mm) used in the embodiment of the present invention, as shown in Figure 3, not only the surface is very rough, but the surface defects inside 122 It can be seen that) is formed deep.

Therefore, in order to form the corrosion resistant layer 140 to obtain the ferritic stainless steel wire 100 having improved corrosion resistance, the surface defects 122 must be removed by artificially smoothing the surface of the raw material material 120. That is, the surface defect removal step (S200) is performed after the material preparation step (S100).

The surface defect removal step (S200) was carried out in two processes in the embodiment of the present invention.

That is, the surface defects 122 are removed by electrolytic polishing to remove the surface defects 122, and the low melting point alloy plating process is performed to fill the surface defects 122 by the low melting point alloy. will be.

The electropolishing process is carried out for 5 minutes or more at a current density of 30 A / dm ² or more in a solution having a concentration ratio of phosphoric acid and sulfuric acid of 9: 1, and the low melting alloy plating process uses Ni-P or Ni-B as a raw material ( 120) The process of plating on the outer surface will be described in detail in the following examples.

After the surface defect removal step (S200), a nickel plating step (S300) is performed. The nickel plating step (S300) is a process of electroplating an alloy containing nickel on the outer surface of the raw material 120.

That is, the nickel plating step (S300) is a process of supplying the raw material 120, performing degreasing, pickling and washing with water, and then plating nickel.

After the nickel plating step (S300), a diffusion heat treatment step (S400) is performed. The diffusion heat treatment step (S400) is a main part of the manufacturing method of the present invention, the nickel plated layer 130 plated on the outer surface of the raw material 120 to diffuse to the surface of the ferritic stainless steel wire of the raw material 120 By increasing the content of nickel near the outermost surface, the surface has the same corrosion resistance as the austenitic stainless steel wire, and the inside has the ferritic stainless steel wire disposed so as to have high hardness, high conductivity, and magnetic properties.

In the diffusion heat treatment step (S400) is carried out for 30 seconds to 10 minutes in an inert or reducing atmosphere of 500 to 900 ℃, it will be described in detail below.

After the diffusion heat treatment step S400, a wire diameter adjustment step S500 for adjusting the outer diameter size of the manufactured ferritic stainless steel wire 100 may be selectively performed.

That is, the wire diameter adjusting step (S500) is a process of extruding to meet the outer diameter of the finally required ferritic stainless steel wire 100, wherein the corrosion-resistant layer 140 lubricating action to reduce the friction by ferritic stainless steel Manufacturing of the steel wire 100 can be facilitated.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 4 to 8.

First, a representative ferritic stainless steel STS430 steel wire having a diameter of 5.5 mm was drawn to prepare a raw material 120 having a diameter of 1 to 2 mm.

In this case, as shown in FIG. 3, the raw material 120 has a very rough surface, and a plurality of surface defects 122 are formed.

This is because defects occurring on the surface of the raw material 120 and defects generated during drawing are generated in the longitudinal direction while the wire diameter is reduced by the die during the drawing process.

Thereafter, nickel is plated on the outer surface of the raw material 120 to form a nickel plating layer 130, and the formed nickel plating layer 130 is partially filled into the surface defect 122 and coated as shown in FIG. 4.

After the nickel plating step (S300), a diffusion heat treatment step (S400) is performed. The diffusion heat treatment step (S400) is a process for allowing the nickel plating layer 130 to be diffused into the raw material 120, by performing for 0.5 minutes to 10 minutes in an inert atmosphere or a reducing atmosphere of 800 ℃ ~ 950 ℃ 5 It has a surface and an internal state of the same state.

In order to examine the effectiveness of the diffusion heat treatment step (S400), as shown in FIG. 6, the component distribution before and after the heat treatment of the ferritic stainless steel wire 100 was tested. As a result, the nickel plated layer 130 did not undergo heat treatment. The interface between the plating layer 130 and the raw material 120 can be confirmed, but the interface was not confirmed in the sample having the corrosion resistant layer 140 formed by heat treatment after the nickel plating layer 130 was formed.

In addition, in the EDS line profile results, the sample before the heat treatment showed a sharp change in concentration near the interface, but in the heat treated specimen, the change in the concentration was very gentle.

In addition, it can be seen that nickel forming the nickel plating layer 130 is diffused into the raw material 120, and chromium and iron included in the raw material 120 are diffused considerably in the nickel plating layer 130.

That is, in the case of the sample without heat treatment, the outer shell layer is composed of only iron and chromium, but after the diffusion heat treatment, nickel, iron, and chromium are mixed, and thus the composition is similar to that of a nickel-based alloy, so that corrosion resistance can be improved. It was expected to be.

Accordingly, the adhesion and corrosion resistance (salt spray test) of the corrosion resistant layer was tested as shown in FIGS. 7 and 8.

At this time, the specimen was prepared in a number having a diameter of 1.0mm and 2.0mm, heat treatment conditions were carried out for 5 minutes in 900 ℃ hydrogen atmosphere.

As a result, when the appearance was visually observed, no plating defects were observed and the state of gloss was observed. The adhesion passed the 180 ° bending test as shown in FIG.

That is, in the bending test, the tape was attached to the bent portion after the sample was bent by 180 °, and the tape was immediately removed to observe the dropping area of the plating layer, but no dropping of the plating layer was found.

In addition, the corrosion resistance was judged by the salt spray test, the first red blue generation date is shown in FIG.

As can be seen from the results shown in the figure, the result of the salt spray test, the first red-blue occurrence date of the nickel-plated ferritic stainless steel wire 100 was very large scattering. In the behavior, when the plating thickness is about 4㎛ or less, red blue color occurs within 2 to 5 days, but specimens which do not occur during this period did not generate red blue color for 20 to 47 days.

This trend was not related to the thickness of the steel wire. That is, in the case of the 430 stainless steel wire, which is the raw material 120, considering that the initial red blue color generation date is within 10 days, the nickel (Ni) plated 430 stainless steel wire is 1.5 times ~ when the red blue color does not occur within 2 to 5 days. It can be seen that the corrosion resistance 4.7 times improved.

Accordingly, as a result of analyzing the cause of the distribution of corrosion resistance, the stainless steel wire is used as the raw material 120 that was subjected to the primary drawing from the initial material (diameter 5.5 mm) to the diameter of 1-2 mm.

At this time, as shown in the surface and cross-sectional photograph of FIG. 3, surface defects caused by the reduction of wire diameter by die during drawing and defects (fresh marks) generated during drawing are generated in the longitudinal direction.

When measuring their surface roughness, the average roughness Ra value is roughly 30 µm or more, and the peaks and valleys are very sharp. Therefore, even if nickel plating is applied to this portion, no plating layer is formed in the valley portion. That is, surface defects 122 and unplated portions are generated in the plating layer.

On the other hand, the corrosion potential of nickel is about 50 to 100㎷ higher than that of 430 stainless steel. Therefore, the surface defect 122 or the unplated portion of the 430 stainless steel is likely to cause galvanic corrosion due to the potential difference with the surrounding nickel plated layer 130.

In addition, such surface defects 122 or unplated sites provide an environment in which corrosion can be accelerated. Therefore, at the surface defect 122 or the unplated part, the 430 Stunnier bristle material is highly accelerated by galvanic corrosion and pitting.

In order to prevent such corrosion, first of all, the plating layer should completely cover the raw material 120 without defects. However, the surface of the drawn base is difficult to be completely plated. This will be described as a phenomenon in which the initial red blue color generation days are late as the plating thickness becomes thick as confirmed in FIG. 8. To this end, the surface defect removal step (S200) described above was performed by the following two methods as a method of alleviating surface roughness.

Example 1 Electrolytic Polishing Process of 430 Stainless Steel Wire

Electrolytic polishing is a process that smoothes the surface while dissolving the surface of metal electrically. It is a surface pretreatment process that provides the surface smoothing effect and removes impurities and defects of the surface, thereby providing a beautiful gloss and improving corrosion resistance. .

Electropolishing is widely used mainly in austenitic stainless steel products, but is rarely used in ferritic stainless steel, and thus electrolytic polishing conditions for the 430 stainless steel wire used in the present invention have been established.

In the embodiment of the present invention, the electrolytic polishing solution was prepared by changing the concentration, relative concentration ratio, current density, electrolysis time, and the like of the mixed solution of phosphoric acid and sulfuric acid and observing the surface to establish the optimum electropolishing conditions.

Figure 9 shows the electropolishing results according to the change of the current density and time in a solution of the concentration ratio of phosphoric acid and sulfuric acid 9: 1.

In other words, when the polishing time is 3 minutes, the polishing seems to be slightly insufficient in the entire current density range, but when the polishing time is 5 minutes, the electropolishing seems to be well performed at 30 A / dm ² or more.

In addition, when the electrolytic polishing time was maintained for 5 minutes in a solution having a concentration ratio of phosphoric acid and sulfuric acid of 9: 1 as shown in FIG. 10, the results of observing the surface of the sample subjected to electropolishing were observed with SEM. When the fall and the large current density was observed that the surface defect 122 is generated on the surface.

This experiment shows that the optimum electrolytic polishing current density of 430 stainless steel is 70 ~ 80A / dm ² .

In addition, in order to completely remove the fresh marks by electropolishing, the thickness removed by electropolishing is preferably at least 15 µm or more, and all surface defects of the raw material 120 are removed.

As described above, the nickel plating layer 130 is formed by plating nickel (Ni) on the outer surface of the raw material 120 subjected to the electropolishing process in the surface defect removing step (S200) (nickel plating step: S300) and 900 ° C. After performing the diffusion heat treatment (diffusion heat treatment step: S400) in the hydrogen atmosphere for 5 minutes, the result of the salt spray test is shown in FIG.

As can be seen in the figure, the red-blue generation time of the 430 stainless steel plate coated with nickel (Ni) as the corrosion-resistant layer 140 is remarkably improved to at least 31 days, it can be seen that the dispersion of the red-blue generation day is also narrowed.

This is because when the nickel (Ni) is plated without electrolytic polishing (as shown in FIG. 8), the red blue generation days occur in the range of 2 to 5 days, or the surface defects 122 of the plating layer due to the surface state of the raw material 120 may occur. This proves that the unplated part is the original.

Therefore, if the surface defects are removed through the surface defect removing step (S200) and a smooth surface is obtained, nickel (Ni) plating and diffusion heat treatment are performed to increase corrosion resistance by an average of 4 times or more.

On the other hand, the surface defect removal step (S200) may be replaced by a low melting alloy plating in addition to the electropolishing process.

That is, Ni-P alloy, which is a low melting point alloy, not only has excellent corrosion resistance but also has a low processing point of 880 ° C., which is used as a brazing material.

Example 2 Low melting alloy plating process

In the embodiment of the present invention, after the Ni-P plating on the outer surface of the raw material 120 is subjected to heat treatment at a temperature (low melting point) of 880 ℃ or more, wherein the dissolved Ni-P of the raw material 120 As the surface defect 122 was filled, diffusion with the raw material 120 was generated.

That is, after Ni (Ni) plating and heating, Ni-P alloy is rapidly dissolved to fill the surface defect 122 of the Ni-P molten alloy (surface defect removal step (S200)) and at the same time the raw material 120 ) And diffusion.

Thereafter, the nickel plating step (S300) was performed to form a nickel plating layer 130 on the outer surface of the Ni-P alloy, followed by diffusion heat treatment step (S400) for 30 seconds at 880 ° C.

As a result, it can be confirmed that the corrosion resistance was improved even in the embodiment in which the low melting alloy plating process was performed as in the electropolishing process as shown in FIG. 13.

The scope of the present invention is not limited to the above-described embodiments, and many other modifications based on the present invention will be possible to those skilled in the art within the scope of the present invention.

For example, in the embodiment of the present invention has been described that the manufacturing of the ferritic stainless steel wire is completed when the diffusion heat treatment step (S400) is completed, the wire diameter is adjusted by performing a plurality of extrusion according to the diameter required for the ferritic stainless steel wire. Obviously, the wire diameter adjusting step S500 may be further performed.

In addition, in the embodiment of the present invention, nickel (Ni) is applied as a material of the corrosion resistant layer, but may be applied to replace the chromium (Cr) within the range of the metal having corrosion resistance, of course.

100. Ferritic stainless steel wire 120. Raw materials
122. Surface defects 130. Nickel plated layer
140. Corrosion resistant layer S100. Material preparation stage
S200. Surface defect removal step S300. Nickel Plating Step
S400. Diffusion heat treatment step S500. Wire diameter adjustment stage

Claims (7)

A material preparation step of preparing a raw material composed of ferritic stainless steel,
A surface defect removal step of removing and flattening a surface defect formed inward from an outer surface of the raw material;
A nickel plating step of forming a nickel plating layer on an outer surface of the raw material from which the surface defects are removed;
And a diffusion heat treatment step of forming a corrosion resistant layer by heat-treating the raw material and the nickel plated layer to diffuse the nickel plated layer. The method of claim 1, wherein the surface defect removal step,
A method for producing a ferritic stainless steel wire having a corrosion resistant layer, characterized in that any one of an electropolishing process and a low melting alloy plating process is applied. The electrolytic polishing step according to claim 2,
A method for producing a ferritic stainless steel wire having a corrosion resistant layer, characterized in that the concentration ratio of phosphoric acid and sulfuric acid is 9: 1 or more at a current density of 30 A / dm ² or more for 5 minutes or more. The method of claim 2, wherein the low melting alloy plating process,
A method for producing a ferritic stainless steel wire having a corrosion resistant layer, characterized by plating Ni-P or Ni-B on the outer surface of the raw material. The method of claim 1, wherein the nickel plating step,
Method for producing a ferritic stainless steel wire having a corrosion-resistant layer characterized in that the nickel plating layer on the outer surface of the raw material to a thickness of 0.1㎛ to 2% of the raw material wire diameter. The method of claim 1, wherein the diffusion heat treatment step,
Method for producing a ferritic stainless steel wire having a corrosion resistant layer, characterized in that carried out for 30 seconds to 10 minutes in an inert or reducing atmosphere of 500 to 900 ℃. According to claim 1, After the diffusion heat treatment step,
Method for producing a ferritic stainless steel wire having a corrosion-resistant layer characterized in that the wire diameter adjustment step for adjusting the outer diameter size of the manufactured ferritic stainless steel wire is carried out.

Images