JP3094491B2 - Sheet-shaped or wire-shaped heater material and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a member suitable for use in a corrosive environment at high temperatures, typically a heater material, and a method for producing the same.

[0002]

2. Description of the Related Art With respect to various metal members used at high temperatures, there is a strong demand for improvement in corrosion resistance. For example, 20Cr of iron-chromium alloy
-5Al-Fe alloy FCH1 has relatively high corrosion resistance,
"FCH51" having a low Cr and Al content (product code of Daido Steel Co., Ltd.), namely, 15Cr-3Al-F
The e-alloy is somewhat inferior in high-temperature corrosion resistance, but is inexpensive and excellent in workability, so that it is widely used as a heater material.
Accordingly, there has been a strong demand for a heater material having excellent oxidation resistance and corrosion resistance at high temperatures and good workability.

[0003] The present inventors have attempted to respond to this demand by, for example, first providing a heater made of FCH51 alloy with Al.
_An attempt was made to coat a heat-resistant and corrosion-resistant material such as ₂ O ₃ to form a protective layer. However, due to the difference in the coefficient of thermal expansion, the coating peeled off after repeated heating and cooling, which was not a practical measure. I understand.

[0004] Next, when a protective layer was formed by vapor deposition of Al ₂ O ₃ , the durability was improved. However, it was concluded that vapor deposition was inefficient and costly, so that it was difficult to spread.

[0005]

The first object of the present invention is to solve the above is an alloy mainly composed of Fe as a base material, a heater material used at high temperatures, Al ₂ O ₃ were firmly bonded to the surface
To provide a sheet-like or wire-like heater material having a protective layer and having enhanced corrosion resistance, especially high-temperature oxidation resistance,
And a method for producing such a heater material at low cost.

A second object of the present invention is to provide a heater material which is made of an alloy containing Fe as a main component and which is used at a high temperature and which has an Al ₂ O ₃ protective layer firmly bonded to the surface thereof. It is an object of the present invention to provide a sheet-like or wire-like heater material having enhanced chemical resistance as well as corrosion resistance, especially high-temperature oxidation resistance, and to provide a method for producing such a heater material at low cost.

[0007]

As shown in FIGS. 2 and 4, a sheet-like or wire-like heater material of the present invention which achieves the first object is an alloy containing Fe as a main component. , Ni, the content is 20
(% By weight or less), a layer (3) in which intermetallic compounds Fe ₃ Al and FeAl are mixed, and a coating layer (4) of Al ₂ O ₃ are formed from the inside to the outside from the surface. Do it.

As shown in FIG. 6, the sheet-shaped or wire-shaped heater material of the present invention which achieves the second object is an alloy containing Fe as a main component (however, when Ni is contained, the alloy is not contained). A coating layer (4) of Al ₂ O ₃ is formed on the surface of a base material (1) having an amount of 20% by weight or less via a layer (5) on which Au or Ag or an alloy thereof is deposited or plated. It becomes.

The base material of the heater material of the present invention is, for example, an FCH51 alloy, that is, Cr: 14.0 to 15.0%.
And Al: 2.80 to 3.30%, and C: 0.
07% or less, Si: 0.10% or less, Mn: 0.60%
In the following, an FCH-based iron-chromium-based alloy consisting essentially of Fe is most suitable.

[0010] In addition, various Fe-based alloys can be used as the base material depending on the use of the heater material. Specifically, the Ni content is 2%, such as various structural steels, ferritic, austenitic, or martensitic stainless steels.
Various Fe-based alloys of 0% by weight or less.

[0011] The Fe alloy used as the base material further includes B, S
i, Mg, Cu, Ca, Mn, Y, Ti, Co, W,
One or more components selected from V, Zr and REM are added to improve the properties of the alloy,
1 and the intermetallic compound of the component can be formed.

The method of the present invention for producing a sheet-like or wire-like heater material is basically composed mainly of Fe, as shown in FIGS. 1 and 2, and FIGS. 3 and 4. The surface of a substrate (1) of an alloy (however, when Ni is contained, the content is 20% by weight or less) is coated with Al or an Al alloy (2), and the obtained coating material is vacuum- By performing annealing in an inert gas and heating in an oxidizing atmosphere, Fe ₃ Al and F
While forming a layer in which eAl is mixed, Al ₂
Generating O ₃ to form a coating layer.

[0013] The method of the present invention for producing a sheet-like or wire-like heater material having particularly excellent chemical resistance is based on an alloy containing Fe as a main component (however, when Ni is contained, the content is 20% by weight or less). B) Au or Ag or an alloy thereof is deposited or plated on the surface of the base material, and Al is coated thereon, and the obtained coating material is annealed in a vacuum or an inert gas and in an oxidizing atmosphere. To form Al ₂ O ₃ on the surface to form a coating layer.

In any of the manufacturing methods, when the base material of the Fe alloy to be used is a sheet-like material, Al
Alternatively, the coating of the Al alloy may be performed by clad rolling. The thickness of the Al or Al alloy foil to be clad rolled is 0.005 to 0.5 mm, and the thickness after rolling is 0.001 to
0.2 mm is appropriate.

On the other hand, when the base material of the Fe alloy is a wire, the coating of Al or the Al alloy is formed by inserting a wire of the base material into a tube of the coating material and performing wire drawing or extrusion. Can do it. In a typical example, the wire diameter of the substrate is about 10 mm,
The thickness of the l or Al alloy tube may be 0.1 to 1.0 mm, as in the case of forming a sheet-like body. To obtain a clad material having a diameter of 0.5 to 3 mm.

Other possible coating methods of Al or Al alloy include immersing the substrate in molten Al or Al alloy, spraying Al or Al alloy on the surface of the substrate, plasma powder welding, chemical Plating or vapor deposition.

When coating is performed using an Al alloy, A
l is B, Si, Mg, Cu, Ca, Mn, Y, Ti, C
An alloy comprising one or more of the components selected from o, W, V, Zr and REM can be used, thereby obtaining the benefit of improved properties depending on the action of the added metal.

The deposition and plating of Au or Ag or an alloy thereof on the base material of the Fe-based alloy can be performed according to known techniques. Taking Au as an example, the layer thickness is:
In the case of vapor deposition, it stops at tens to hundreds of angstroms,
In the case of plating, it is easy to make the thickness 1 to several tens μm.

Annealing in a vacuum or inert gas is 400
To 900 ° C, preferably from 400 to 600 ° C.
This can be done by heating for 0 hours. The next heating in the oxidizing atmosphere may be performed, for example, by heating to a temperature of 400 to 1000 ° C. in the air for 1 to 20 hours.

It should be noted that the wire-shaped body is not limited to the one having a circular cross section as shown in FIG. For example, a clad material having a cross-sectional shape as shown in FIG. 5 can be obtained by rolling using a grooved roll, and further roll-rolled into a product having a shape close to a sheet-like body. This type of wire-like product is more resistant to corrosion since both side edges of the substrate are also covered.

[0021]

A sheet or wire of an Fe-based alloy as a substrate (1) and Al coated thereon by means such as cladding.
Alternatively, between the Al alloy layer (2) and the Al alloy layer (2), they adhere to each other by diffusion in the process of vacuum annealing, and the diffusion further proceeds by subsequent heating in an oxidizing atmosphere. As a result, Fe ₃ Al or FeAl is generated at each position in the depth direction depending on the amount of Fe and Al components. When the thickness of the coated Al layer is thick, a gradient occurs in the concentration of these products. However, when the layer is thin and the heat treatment is sufficiently performed, the concentration gradient in the clad layer almost disappears, and the concentration is almost one. Thus, a layer in which Fe ₃ Al and FeAl are mixed is formed.

The above alloy component having the property of forming an intermetallic compound with Al in the Fe-based alloy, ie, B, Si,
Mg, Cu, Ca, Mn, Y, Ti, Co, W, V, Z
When one or more of r and REM are present, and when these components are present in the clad Al alloy, in addition to the Fe-Al intermetallic compound, Is also formed.

On the other hand, when Au or Ag or a layer of these alloys (hereinafter, referred to as “Au layer”) is provided on the surface of the base material of the Fe-based alloy, annealing in vacuum or inert gas is performed. In the process, between the base metal and the Au layer, and Au
Diffusion occurs between the layer and the Al or Al alloy layer. A
If there is a component that forms an intermetallic compound with u or Ag or an alloy thereof, an intermetallic compound of the combination is generated near the interface, but no Fe-Al intermetallic compound is generated. However, if the Au layer is thin and the heat treatment is performed at a high temperature for a long time, a reaction between the metal components that have passed through the Au layer may occur.

In any of the above cases, Al present on the surface
Is oxidized by heating in an oxidizing atmosphere and
It becomes ₂ O ₃ . In addition, the coating layer may be formed by growing in the form of Al ₂ O ₃ whiskers. While Al ₂ O ₃ is generated, Al also diffuses into the Fe-based alloy of the base material by diffusion and is well fused at the joint portion, and further undergoes oxidation to change to Al ₂ O ₃ . As a result, the coating layer of Al ₂ O ₃ exists with its base anchored in the base metal, and firmly covers and protects the base.

In this way, Al ₂ O ₃ grows entangled on the surface of the base metal and covers it densely. Although this is a dense Al ₂ O ₃ oxide layer, it is unavoidable that micropores exist in some parts. Corrosive chemicals such as salt water may enter through such small holes and attack the base metal, but in the present invention, the corrosion resistance is greatly improved by the Fe-Al-based metal oxide. Even if a thin layer is provided on the base material by vapor deposition or plating of Au or Ag or an alloy thereof, penetration of a corrosive chemical solution can be prevented since they themselves have high corrosion resistance.

[0026]

[Example 1] An aluminum foil having a thickness of 0.1 mm was clad on both sides of a thin plate of an FCH51 alloy having a thickness of 0.2 mm by rolling. Rolling was further performed to prepare a clad material having an overall thickness of 0.1 mm and Al layers on both surfaces having a thickness of 0.04 mm.

This was slit into a ribbon having a width of 30 mm, and heated to 600 ° C. for 1 hour in the atmosphere, whereby Al → Al
The change of ₂ O ₃ was caused to grow an oxide layer of Al ₂ O ₃ .

The FCH51 alloy ribbon having the Al ₂ O ₃ coating layer was heated to 1100 ° C. in the atmosphere to measure the amount of increase in oxidation. For comparison, a ribbon of FCH51 alloy only and FCH5
1 alloy ribbon is oxidized by Al deposition and A
With respect to the ribbon having the l ₂ O ₃ coating layer formed thereon, the amount of oxidation was measured under the same conditions. The results are shown in FIG.
It can be seen from the graph of FIG. 7 that the Al ₂ O ₃ coating layer effectively improved the high-temperature oxidation resistance of the FCH51 heater material.

Next, the corrosion resistance against salt spray was examined by repeating the following cycle.

5% NaCl aqueous solution spraying (40 ° C., 4 hours) → wetting (50 ° C., RH 100%, 2 hours) → drying (60 ° C., 2 hours) Also in this case, the Al ₂ O ₃ coating layer was formed for comparison. The test was performed with a non-having FCH51 alloy ribbon and evaluated according to the corrosion state of the surface. The results are shown in the graph of FIG. This graph also shows the improvement in corrosion resistance by the Al ₂ O ₃ coating layer.

Example 2 Au was deposited on both sides of a thin plate of FCH51 alloy having a thickness of 0.2 mm to form an Au layer having a thickness of about 100 angstroms, and an Au layer having a thickness of about 100 Å was formed thereon.
A 15 mm aluminum foil was clad by rolling. Further rolling, the total thickness is 0.05 mm and Au on both sides
A cladding material having a thickness of 30 Å and an Al layer of 0.002 mm was prepared.

This was slit into a ribbon having a width of 30 mm,
1 hour at 00 ° C., then vacuum annealed, to cause a change in the Al → Al ₂ O ₃ by heating 1 hour 600 ° C. in air, Al ₂
The O ₃ oxide layer was grown.

The FCH51 alloy ribbon having the Al ₂ O ₃ coating layer was heated to 1100 ° C. in the atmosphere to measure the amount of increase in oxidation, thereby examining high-temperature oxidation resistance. For comparison, a ribbon of only the FCH51 alloy (Comparative Example) and a ribbon of the FCH51 alloy ribbon directly subjected to Al cladding and subjected to oxidation treatment to form an Al ₂ O ₃ coating layer (Reference Example) were also obtained under the same conditions. The oxidation weight gain was examined.
The results are shown in FIG. From the graph of FIG.
It can be seen that the l ₂ O ₃ coating layer effectively improved the high temperature oxidation resistance of the FCH51 heater material.

Next, the corrosion resistance to salt spray was examined under the same conditions as in Example 1. Also in this case, the ribbons of the comparative example and the reference example were tested and evaluated according to the corrosion state of the surface. The results are shown in the graph of FIG. This graph shows that the corrosion resistance of the Al ₂ O ₃ coating layer is further enhanced by the presence of the Au layer.

Example 3 Fe having the following alloy composition
A base alloy was used as a base material, and an aluminum foil having a thickness of 0.015 mm was subjected to clad rolling on both sides of a sheet having a thickness of 0.2 mm in the same manner as in Example 1 so that the overall thickness became 0. 0
A coating material on a sheet having a thickness of 5 mm and a thickness of each Al layer on both sides of 0.002 mm was prepared.

C Si Mn Cr Ni Mo Ti V Al Other A 0.05 0.3 2.03 14.20 − − 0.53 − 3.05 B: 0.1 B 0.06 1.23 0.86 18.60 − − − − 3.62 Mg: 0.03 C 0.05 0.85 1.58 19.00 9.06 − − 0.5 − REM (La): 200 ppm D 0.08 0.63 0.88 17.59 − 0.48 − − − Ca: 200
ppm The above coating material was subjected to vacuum annealing at 600 ° C. × 1 hour, and then heated in air at 800 ° C. × 68 minutes.
Al ₂ O ₃ was produced.

A bending test and a tensile test were performed on the product using the base material of A. In the bending test, a cycle of bending at 90 ° C., returning to the original state, and bending again is repeated, and the number of times of bending until breaking was reached five times.
The elongation was 3%.

[0038]

According to the present invention, the sheet-shaped or wire-shaped heater material has a structure in which the surface of the base material of the alloy containing Fe as a main component is coated with Al.
By providing and protecting a strong coating layer of ₂ O ₃ , corrosion resistance represented by high-temperature oxidation resistance and salt water resistance is improved. Among the iron-chromium alloys, FCH51 alloy, which is inexpensive and excellent in workability, is used as a base material. By improving its high-temperature corrosion resistance, which is its weak point, it can be used not only in industrial equipment but also in various household appliances. Applications can be expected.

According to the production method of the present invention, such a heater material is formed by an easy-to-implement method such as cladding.
It has been made possible to manufacture by a method of providing an 1 layer and changing to Al ₂ O ₃ . As a result, the Al ₂ O ₃ coating layer having a thickness that can be arbitrarily selected from a wide range, and further having a base layer anchored in the heater material and protected by the coating layer that is firmly bonded, and having high corrosion resistance A heater material is obtained.

In the embodiment in which the Au layer is provided on the substrate,
By having a double coating of u and Al ₂ O ₃ , high temperature oxidation resistance and chemical resistance were further improved.

Further, in the embodiment in which alloy components for forming an intermetallic compound with Al are added to the base metal or the Al alloy layer, the product characteristics are improved according to the action of the alloy components, for example, the base material and Benefits such as improved intermetallic compounds, improved adhesion between the intermetallic compounds and the Al ₂ O ₃ coating layer, and improved workability due to improved ductility of the intermetallic compounds by B and Mn can be obtained.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a material for explaining a manufacturing process when a heater material of the present invention is a sheet.

FIG. 2 is a conceptual cross-sectional view showing a structure of a heater material according to the present invention when the heater material is a sheet.

FIG. 3 is a cross-sectional view of a material corresponding to FIG. 1 for explaining a manufacturing process when the heater material of the present invention is a wire-like body.

FIG. 4 is a conceptual cross-sectional view corresponding to FIG. 2 and showing a structure of the heater material of the present invention when the heater material is a wire.

FIG. 5 is a conceptual cross-sectional view similar to FIG. 4, showing a structure of a wire-like body in a mode different from that of FIG. 4;

FIG. 6 is a diagram showing the structure of the heater member of the present invention in a sheet-like body in a mode different from that of FIG. 2;
Sectional drawing similar to.

FIG. 7 is a graph showing data of one example of the present invention, showing an increase in oxidation at 1100 ° C. in the atmosphere.

FIG. 8 is a graph showing data of a salt spray test, which is data of one example of the present invention.

FIG. 9 is a graph showing the increase in oxidation at 1100 ° C. in the air, which is data of another example of the present invention.

FIG. 10 is a graph showing data of a salt spray test, which is data of another example of the present invention.

[Explanation of symbols]

Mixed layer 4 Al ₂ O ₃ coating layer 5 Au layer between the first substrate 2 Al or Al alloy 3 Fe ₃ Al and FeAl

Continuation of the front page (51) Int.Cl. ⁷ identification code FI H05B 3/12 H05B 3/12 B (58) Field surveyed (Int.Cl. ⁷ , DB name) C23C 28/00 C23C 8/16 H05B 3 / 12

Claims (12)

(57) [Claims] An alloy containing Fe as a main component (however, Ni
Is contained on the surface of the base material of which the content is 20% by weight or less, from the inside to the outside, the intermetallic compound Fe
_A sheet-like or wire-like heater material formed by forming a layer in which ₃ Al and FeAl are mixed and a coating layer of Al ₂ O ₃ . 2. An alloy containing Fe as a main component (however, Ni
Is contained, the content of which is 20% by weight or less) on the surface of a substrate, a coating layer of Al ₂ O ₃ is formed via a layer on which Au or Ag or an alloy thereof is deposited or plated. Sheet or wire heater material. 3. A Ni alloy having a Ni content of 20% by weight, such as various structural steels, FCH-based iron-chromium-based alloys, ferrite-based, austenitic-based, or martensitic-based stainless steels. The heater material according to claim 1 or 2, which is any of the following Fe-based alloys. 4. An Fe alloy as a base material, in addition to the above composition, comprises B, Si, Mg, Cu, Ca, Mn, Y, Ti, C
The heater material according to claim 3, which is an Fe-based alloy further containing one or more components selected from o, W, V, Zr, and REM. 5. An alloy containing Fe as a main component (however, Ni
Is contained, the content of which is 20% by weight or less), the surface of the substrate is coated with Al or an Al alloy, and the obtained coating material is annealed in a vacuum or an inert gas and in an oxidizing atmosphere. To form a layer in which Fe ₃ Al and FeAl are mixed on the base material,
method of manufacturing a heater material comprises forming a coating layer to produce a l ₂ O _3. 6. An alloy containing Fe as a main component (however, Ni
Is contained, the content of which is 20% by weight or less) on the surface of a substrate, Au or Ag or an alloy thereof is vapor-deposited or plated, and Al is coated thereon. A method for producing a heater material, comprising annealing in a vacuum or an inert gas and heating in an oxidizing atmosphere to form Al ₂ O ₃ on the surface to form a coating layer. 7. The base material of the Fe alloy is a sheet-like body,
7. The method according to claim 5, wherein the coating of Al or an Al alloy is performed by clad rolling. 8. The base material of the Fe alloy is a wire-like body,
7. The method for producing a heater material according to claim 5, wherein the coating of Al or Al alloy is performed by inserting a base wire into a tube of the coating material and drawing or extruding the wire. 9. The coating of Al or Al alloy is performed by immersing the substrate in molten Al or Al alloy, spraying Al or Al alloy on the surface of the substrate, plasma powder welding, chemical plating, sputtering or vapor deposition. The method for producing a heater material according to claim 5 or 6, which is performed. 10. The method according to claim 1, wherein the base material of the Fe alloy is a lump.
l or Al alloy coating, the molten Al or Al
7. The method for producing a heater material according to claim 5, wherein the method is carried out by immersion in an alloy, thermal spraying of Al or an Al alloy on a substrate surface, plasma powder welding, chemical plating, sputtering or vapor deposition. 11. An Al alloy containing B, Si,
Mg, Cu, Ca, Mn, Y, Ti, Co, W, V, Z
7. An alloy prepared by adding one or more components selected from r and REM.
Method of manufacturing heater material. 12. The annealing in a vacuum or an inert gas is performed by
7. The heater material according to claim 5, wherein the heating is performed under a heating condition of 100 to 900 [deg.] C. for 1 to 200 minutes, and heating in an oxidizing atmosphere is performed by heating to a temperature of 400 to 1000 [deg.] C. in the atmosphere for 1 to 20 hours. Manufacturing method.