KR20080092715A - Method for making color oxide layered metallic materials with high corrosion-resistance - Google Patents

Abstract

A method for making color oxide layered metallic materials with high corrosion-resistance is provided to increase corrosion resistance and obtain high glossiness by oxidizing a process material in an oxidative atmosphere of 180 to 1,200°C to form a color anodized layer on a surface of the process material. A method for making color oxide layered metallic materials with high corrosion-resistance comprises the steps of: obtaining a process material by selecting one of processes of surface-treating/plating/vacuum-depositing a metal material; and oxidizing the process material in an oxidative atmosphere of 180 to 1,200°C for 5 sec to 10 min to form a color anodized layer on the surface of the process material. The color anodized layer is formed through one heating device selected from a high speed roller hearth type and a mesh belt type of continuous oxidation equipment and through a continuous high frequency heating device.

Description

Method for Making Color Oxide Layered Metallic Materials with High Corrosion-Resistance

The present invention relates to a method of manufacturing a metal material having a high corrosion-resistant color oxide film layer, and more particularly, a high corrosion-resistant color oxide film layer having high corrosion resistance, uniform color tone and a variety of colors and beautiful decoration. It relates to a method for producing a metal material having.

In recent years, as the industry develops and the life is improved, the color metal materials reflecting various color concepts that can be applied to various household goods, decorations, metal crafts, etc., while still retaining the unique characteristics of metals. Demand is increasing.

Therefore, attempts have been made to obtain color tints by forming an oxide film layer on a metal material. Thus, when looking at the material having a color anodized layer, the color tint expressed in the metal material is formed in a variety of colors due to the difference in the interference effect of light according to the thickness of the anodized layer, in order to obtain a uniform color tone, the oxidation of a uniform thickness It is necessary to form a coating layer, which requires uniform heating of the metal material.

In addition, the oxide layer having a uniform thickness has a great influence on the oxide particle size constituting the oxide layer, such as corrosion resistance, roughness and adhesion to the base material. When the particles are coarse, cracks may occur in the oxide layer or Poor adhesion, poor corrosion resistance, poor surface roughness and poor gloss.

That is, in order to achieve uniform color tone, adhesion to the base material, corrosion resistance, and improved glossiness, a uniform oxide film layer must be formed on the metal material quickly. For this purpose, it is necessary to heat the metal material uniformly and quickly in the heat treatment process. .

Looking at the above heating process, in general, when heating at a low temperature for a relatively short time it was possible to obtain a solid color of golden color, when heating for a long time there was no big difference in the color tone, but there was a problem of low economic efficiency. On the contrary, when heating at a high temperature for a long time, various colors are formed, but the oxide layer is thick and the particles are coarse, resulting in poor corrosion resistance and significant loss of surface glossiness. Therefore, in order to express high corrosion resistance and uniform color tone, it is required to manage and control the heat treatment conditions in particular.

On the other hand, as a method for producing a color stainless steel has been disclosed in Japanese Patent Publication No. 60-21370 for a variety of color tones that appear according to the heating temperature when the 18-8 stainless steel is heated in an electric furnace for 15 minutes at various temperatures. However, as a result of the corrosion resistance test of the stainless steel pipe manufactured by the above production method, when the 5% saline spray test on the color stainless steel pipe, discoloration occurred after 4 hours, and after 7 hours was found.

In general, considering that the corrosion time of the salt spray test of 18-8 stainless steel is about 500 hours, a variety of colors were obtained for the steel as the manufacturing method, but sacrifice of corrosion resistance was inevitable. Therefore, there is a problem in that the conventional method cannot produce a high corrosion-resistant color stainless steel.

As a result of intensive research, the present inventors have limited the heating time from a few seconds to 10 minutes at a high temperature to rapidly oxidize heat, thereby forming a uniform color and suppressing grain growth of the oxide film layer, thereby ensuring high corrosion resistance. The present invention has been completed by discovering that the present invention is present.

Accordingly, the present invention has been made in view of the problems of the prior art, and the present invention improves the oxidation heat treatment conditions so that the metal material can have various color hues while having high corrosion resistance, while sufficiently securing high corrosion resistance and high quality color oxidation. It is an object of the present invention to provide a method for producing a metal material having a coating layer.

In addition, another object of the present invention is to provide a high corrosion resistance, high gloss, improved adhesion to the base material and to convey the product at high speed to heat uniformly for a short time to form a uniform and various color oxide layer and smooth the oxidizing gas in the device High corrosion resistance to maintain uniform distribution of flow and temperature, and to heat the surface uniformly regardless of its size, shape and surface area, even for each product or the same product, in order to obtain a commercially reproducible uniform color product It is to provide a method for producing a material having a color oxide film layer.

Other objects and advantages of the invention will be described below and will be appreciated by the embodiments of the invention.

In order to achieve the above object, the present invention comprises the steps of (a) obtaining a treated material by at least one treatment selected from the surface treatment treatment, plating treatment and vacuum deposition treatment of the metal material; And (b) a color oxidation process step of forming a color oxide film layer on the surface of the treated material by subjecting the treated material to an oxidative heat treatment under an oxidizing atmosphere of 180 ° C. to 1,200 ° C. for 5 seconds to 10 minutes. Provided is a method of manufacturing a metal material having a high corrosion resistant color oxide film layer.

In this case, the color oxidation process may be performed using a high speed mobile roller hearth type or a mesh belt type heating device of a continuous oxidation equipment, or a continuous high frequency heating device. As a result, a more uniform color oxide film layer can be formed on the treated material. However, the oxidation heat treatment apparatus is not particularly limited as long as the above heat treatment process conditions are satisfied.

The continuous heating apparatus includes a heat transfer part for supplying heat to the processing material in the housing, a high speed transfer part for continuously transferring the processing material into the heat transfer part, and an oxidative property installed in the housing for oxidation heat treatment. It includes a gas circulation for smooth stirring and uniform temperature distribution of the gas.

On the other hand, in the present invention, the metal material may be selected from, for example, nitrided steel, stainless steel, copper alloy, aluminum alloy or zinc alloy, including general steel.

Further, the surface treatment may be performed by one method selected from buffing, lapping, polishing, polishing and electropolishing. In addition, the plating treatment may be performed by one method selected from nickel plating treatment, chromium plating treatment, nickel-chromium plating treatment and nickel alloy plating treatment.

Quenching heat treatment, tempering heat treatment, carburizing heat treatment, annealing heat treatment, and normalizing heat treatment of steel materials and heat treatment of non-ferrous materials are carried out after charging the product into the furnace and preheating process. It is regarded as the process time. At this time, even if there is a slight temperature difference at a predetermined temperature, the microstructure is the same.

However, in the surface oxidation heat treatment, an oxide film layer is already formed during preheating, and even at a predetermined temperature, since the heating temperature is different for each location of the material, there is a problem that a difference occurs in the thickness of the oxide film layer so that a uniform color tone cannot be obtained.

At this time, the heating device for forming the oxide film layer is typically a batch type (batch type) heating device and a continuous type (continuous type) heating device.

The batch type heating device includes a fit type, a sealed quench, a box type, etc. This batch type device is the most widely used device, which opens a lid of a device, loads a product or part, and then closes the lid. After going through the process of opening the lid again to take out the product.

As another heating device, the continuous heating device may be a roller hearth type, a mesh belt type, or the like. The continuous heating device is a device for continuously processing a material using a conveying device.

Here, in the continuous heating apparatus, even if the temperature of each region in the housing is different from each other, since all the materials pass through the same temperature region for the same time, there is almost no problem of unevenness of color tone due to the nonuniformity of the oxide film layer.

However, the continuous heating apparatus used in the related art has a heating zone of 5m to 20m in length and transfer time of the product takes about 1.5 hours to 2 hours, so that when the heating is performed for a long time, the thickness of the oxide layer becomes thick and the base material and the oxide layer Due to the difference in the coefficient of thermal expansion of the cracks to lose the gloss and the color tone is close to black, there is a problem in the present invention used an improved continuous heating apparatus to be heated in a short time at high temperature.

At this time, in the present invention, in order to manufacture a material having a high corrosion-resistant color oxide film layer, it is preferable to use a continuous heating device that is easy to heat at a high temperature for a short time. It does not mean to exclude.

Meanwhile, according to the present invention configured as described above, an oxidation heat treatment is performed through uniform heating at a high temperature in a short time for a treated material obtained by subjecting a metal material to at least one selected from a surface treatment treatment, a plating treatment, and a vacuum deposition treatment. Because it forms a color oxide film layer, various and uniform colors are expressed on the material, and the decorative property is excellent, and its application field is not only extensive but also the corrosion resistance of the material is improved by applying uniform heating at high temperature in a short time. A material having an oxide film layer can be produced.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

First, in the case of the material to which the target metal material is nitrided or stainless steel, surface processing such as polishing, buffing, lapping, polishing or electropolishing is performed to obtain uniform roughness.

In the plating process, one material selected from steel, nitrided material, stainless steel, copper alloy, aluminum alloy and zinc alloy is used in nickel plating, chromium plating, nickel-chromium plating and nickel-alloy plating. Surface treatment can be performed by one selected plating treatment.

Then, the processing material obtained through at least one selected from the above surface treatment treatment, plating treatment, and vacuum deposition treatment is put into a heating apparatus, followed by oxidation and heat treatment to perform a color oxidation process.

The color process is to form a color oxide film layer by performing an oxidation heat treatment on the surface of the treated material subjected to at least one selected from the above surface treatment treatment, plating treatment, vacuum deposition treatment, to express the oxidation heat treatment conditions, respectively. According to the color to be performed, the temperature at which the oxidative heat treatment is performed is performed in the range of 180 ° C to 1,200 ° C for 5 seconds to 10 minutes.

For this reason, when heating the treated material at a low temperature for a short time, only golden color can be obtained, and various color tones cannot be expressed. On the other hand, when heating at low temperature for a long time, there is no big difference in color tone, but there is a problem of low economic efficiency. Because.

Furthermore, when heated at high temperature for a long time to obtain a variety of colors, it is possible to obtain a colored oxide film layer of a certain thickness, but it is difficult to achieve the desired gloss and corrosion resistance by coarse particles of the oxide.

Particularly, in the case of stainless steel, the oxide film layer formed through the color process step is composed of iron oxide, chromium oxide, nickel oxide, etc. These oxides have roughness due to different growth characteristics of each particle in a given temperature range when heated at a high temperature for a long time. In addition to the deterioration of the chromium oxide passivation film due to the coarsening of chromium oxide particles, the formation of iron oxide, the precipitation of Cr carbide at the grain boundary, and the like, the corrosion resistance decreases.

On the other hand, in terms of the heating rate, when the heating rate is small, there is a problem that the particles of the oxide film layer become coarse during heating at a predetermined temperature, thereby deteriorating corrosion resistance.In the case of heating for a long time, the thickness of the oxide layer becomes thick and the thermal expansion of the base material and the oxide layer The difference in coefficients leads to cracks, loss of gloss and hue closer to black.

Therefore, in order to obtain a high corrosion resistance material having various color tones, the oxidation heat treatment conditions are respectively 5 seconds to 10 minutes in the range of 180 ° C. to 1,200 ° C. depending on the color to be expressed. It is good to carry on.

Thereafter, the material in which the color oxide film layer is formed through the oxidation heat treatment is subjected to a post-treatment process such as a cooling process.

Referring to the heating apparatus for the oxidative heat treatment, the heat transfer unit using electricity, gas, oil, etc. as a heat source to supply heat to the processing material in the housing, and the high speed that the material is continuously transferred into the heat transfer unit And a gas circulation unit installed in the housing to smoothly stir and uniformly distribute the oxidizing gas for oxidative heat treatment.

Here, the high frequency coil may be installed outside the heat transfer unit to heat the high frequency material to be processed.

The high-speed feeder may control the pushing speed at the inlet and the pulling speed at the outlet when the processing material is a pipe or a rod, and may adjust the winding speed when the processing material is a wire shape, and the processing material may be a plate or any shape. In the case of having it, the feed speed can be adjusted by directly placing it on the mesh belt or by the ratio of the gear size of the sprocket attached to the driving motor in the roller-shush heating device equipped with the jig.

In addition, the gas circulation unit is provided with a circulation fan installed in the upper, lower, or upper and lower portions of the housing for smooth agitation and uniform temperature distribution of the oxidizing gas in the housing for uniform heating, and smooth discharge of the gas in the housing. It includes a gas discharge device including a valve and installed in the form of a chimney adjustable height in the upper part of the housing or the center of the housing or near the material inlet in order to induce the intake of the oxidizing gas and to maintain a uniform temperature in the housing.

In addition, the present invention can produce a color steel by applying a high frequency induction heating method in addition to the heating device, when the high frequency induction heating method is applied to the color in a short time compared to the batch or continuous heating device described above Can be expressed.

Accordingly, the present invention provides an oxide film layer having a uniform thickness and fine particles in a short time through the above-described continuous heating apparatus, and can also obtain a variety of glossy color oxide film layers and at the same time excellent in corrosion resistance. Manufacturing is possible.

Example 1

The STS 304 stainless steel wire (0.4mm diameter) was electropolished and heated for 5 minutes while passing through the heat transfer part heated to 550 ° C. of the continuous heating apparatus, followed by cooling. As a result, the surface color was golden-colored anodized layer.

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 2

After the STS 304 stainless steel wire (0.4 mm diameter) was electropolished and passed through the heated portion heated to 900 ° C. in a continuous heating apparatus for 30 seconds, the resultant was cooled and the color of the blue oxide layer was formed.

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 3

After electrolytic polishing of STS 304 stainless steel plate (30mm × 50mm × 1.8mm), it was heated for 3 minutes into the heat transfer part maintained at 700 ℃ in the continuous heating device and then cooled, and the surface color was golden-colored color oxide film layer. .

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 4

After electrolytic polishing of STS 304 stainless steel plate (30mm × 50mm × 1.8mm) and heating it for 1 minute into the heat transfer part maintained at 900 ° C in a continuous heating apparatus, the resultant was cooled and the color of the blue oxide color layer was formed. .

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 5

After electrolytic polishing of STS 304 stainless steel wire (0.4mm diameter) of 1m length and heating at 550 ℃ for 8 minutes using a high-frequency induction heating apparatus, the resultant was cooled for 8 minutes, and the surface color was golden-colored oxide film layer.

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 6

After buffing the STS 304 stainless steel rod with a length of 30cm and a diameter of 4.5cm, it was heated at 900 ℃ for 1 minute using a high-frequency induction heating apparatus and then cooled for 1 minute. As a result, the surface color formed a blue oxide colored layer. .

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 7

A semi-circular electropolished nickel-plated joint with a width of 3 cm, a height of 7 cm, and a thickness of 2.0 tons was heated for 9 minutes in an air atmosphere at 550 ° C. using a mesh belt type high speed feeder to obtain a golden color.

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

Example 8

 Steel pipes having a diameter of 30 mm, a thickness of 0.7 mm, and a length of 300 mm were nitrided, buffed, and heated in an air atmosphere at 800 ° C. for 1 minute to obtain blue color.

5% salt spray test of the material showed that the corrosion resistance was excellent as about 450 hours.

The method for producing a highly corrosion-resistant color steel of the present invention made as described above provides the following effects.

First, it is possible to provide a method of manufacturing a material having a high corrosion resistance color oxide film layer having a variety of uniform color tones and at the same time excellent corrosion resistance that can not be realized by conventional methods.

Second, a heating device capable of uniformly heating at a high temperature for a short time may provide a material having a high corrosion resistance, high gloss, improved adhesion to a base material, and a commercially reproducible uniform and various color oxide film layer.

As described above, although the present invention has been described by means of a limited embodiment, the present invention is not limited thereto and will be described below by the person skilled in the art and the technical spirit of the present invention. Of course, various modifications and variations are possible within the scope of the claims.

Claims (6)

(a) treating the metal material with at least one selected from a surface treatment treatment, a plating treatment, and a vacuum deposition treatment to obtain a treated material; And (b) a color oxidation process step for forming a color oxide film layer on the surface of the treated material by subjecting the treated material to an oxidative heat treatment under an oxidizing atmosphere of 180 ° C to 1,200 ° C for 5 seconds to 10 minutes. Method for producing a metal material having a corrosion-resistant color oxide film layer. The method of claim 1, wherein the color oxidation process is any one heating device selected from a high speed roller hearth type and a mesh belt type of a continuous oxidation equipment, or continuous A method of manufacturing a metal material having a highly corrosion-resistant color oxide film layer, characterized in that to form a uniform color oxide film layer of the treated material through a high frequency heating device. The method of claim 2, wherein the continuous heating device, A heat transfer part for supplying heat to the treated material in a housing; A high speed transfer unit for continuously conveying the processed material into the heat transfer unit; The method of manufacturing a metal material having a highly corrosion-resistant color oxide film layer, which is installed in the housing and comprises a gas circulation unit for smooth stirring and uniform temperature distribution of the oxidizing gas for oxidative heat treatment. The method of claim 1, wherein the metal material is any one selected from general steels, nitrided steels, stainless steels, copper alloys, aluminum alloys, and zinc alloys. . The method of claim 1, wherein the surface treatment is performed by at least one method selected from buffing, lapping, polishing, polishing, and electropolishing. The metal material having a highly corrosion-resistant color oxide film layer according to claim 1, wherein the plating treatment is performed by one method selected from nickel plating treatment, chromium plating treatment, nickel-chromium plating treatment and nickel alloy plating treatment. Manufacturing method.