JPH03183538A - Heat proof composite and core metal, bolt, heater and magnetic composite in use of that - Google Patents

Abstract

PURPOSE:To enable sufficient strength to be obtained even when subjected to high temperature and also enable it to be used stably for a long period by making fire-proof metallic fibers disposed in a basic body comprising a super alloy of a nickel or a cobalt have a specific coated layer of a niobium or a niobic alloy. CONSTITUTION:The title compound has a two layered construction of basic bodies 6 consisting of a nickel or a cobalt, fireproof metallic fibers 3 disposed within the basic bodies and niobic layers 4 consisting of niobium or niobic alloy, and hard metallic layers 5 comprising the hard metal of an iron group covering the niobic layers, and is equipped with coating layers coating the fireproof metallic fibers. As fire-proof metallic fibers, it is preferred to employ W wire, Mo wire and Ta wire, and W wire containing at least a kind of ThO2, K, Si and Al. A fireproof composite serves to cover the surface of the fireproof metallic fibers 3 disposed within the basic bodies 6 comprising a hard metal of an Ni or a Co with super alloy layers comprising the niobic layers 4 and iron-based super alloy 5 and also serves to prevent various elements from dispersing from the super alloy of the Ni or Co as a matrix 6 to the fire-proof metallic fibers.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention provides a heat-resistant composite having excellent strength at high temperatures and high-temperature oxidation resistance, and core metals, bolts, and heaters using the same; The present invention also relates to a magnetic composite having excellent strength at high temperatures.

(Prior Art) Recently, from the viewpoint of resource conservation, increasing the efficiency of large energy conversion devices such as gas turbines has become important.

A basic means of achieving higher efficiency is increasing the operating temperature of conversion equipment. In this case, the temperature resistance of the members used in the equipment poses a structural problem. As materials for this energy conversion device, superalloys such as iron-based (Fe-based), cobalt-based (Co2Ji), or nickel-based (Ni-based) have been used. However, even with the use of these superalloys, the development of materials to increase the withstand temperature is nearing its limit.

In addition, recently, machines and structures that are used in harsh environments where humans cannot directly work have begun to be manufactured in the utilization of underground and seabed resources and in Uichi Development':9. Many of these are exposed to highly corrosive environments at high temperatures and pressures. Therefore, the properties required of the materials constituting these structures have become extremely strict.

In order to satisfy this requirement, the application of ceramics such as Si3N4 and SiC is also being considered.

However, due to their low toughness, these ceramics are still not suitable for use as feed at a practical level.

Furthermore, since humans cannot work directly under the above-mentioned adverse environment, magnetic materials such as magnets are often used. However, because the environment in which they are used is extremely harsh, existing magnetic materials cannot meet the strength of magnetic poles and cores, especially high-temperature strength.

Under these circumstances, composites in which the above-mentioned superalloys or magnetic metal materials are reinforced with refractory metal fibers are beginning to attract attention as next-generation heat-resistant materials and heat-resistant magnetic materials.

An example of such a composite body is one in which a tungsten wire (W wire), which is a refractory metal fiber, is embedded and integrated into a base made of a superalloy or a magnetic metal material. This composite is a combination of the excellent high-temperature mechanical properties of W wire and the high-temperature corrosion resistance of a superalloy, or the combination of the high-temperature mechanical properties of W wire and a magnetic metal material. It is intended.

By the way, in composites in which such refractory metal fibers are embedded in a base, interdiffusion becomes a serious problem even at high temperatures. In particular, heat-resistant composites using Ni-based superalloys as a substrate are attracting attention because they have excellent high-temperature properties such as superior strength at high temperatures compared to other superalloys. N
Compared to other Fe-based superalloys, the reaction rate of refractory metal fibers with W is two or more orders of magnitude higher, so the above-mentioned interdiffusion becomes a more serious problem. In other words, in a W-wire-strengthened Ni-based alloy composite that combines Ni-based superalloys with excellent high-temperature oxidation resistance, an interdiffusion reaction between Ni and W occurs at high temperatures of 800°C or higher, and the strength of the W wire deteriorates. do. Therefore, the use of this composite has a problem in that the practical soil is limited to temperatures below 800° C., although it has superior high-temperature properties compared to Ni-based superalloys and other superalloys. Also,
Regarding the composite of magnetic metal + material and refractory metal fiber,
A similar problem occurs when a general Fe-based alloy containing Ni is used as the base. For example, in the case of permalloy, the heat treatment temperature is as high as about 1100° C., and the strength of the W wire is deteriorated due to the reaction caused by this heat treatment.

Furthermore, since many refractory metal fibers containing W wire have a smaller coefficient of thermal expansion than other metals, there is also the problem that thermal stress generated between the fibers and the matrix cannot be avoided even by compositing them.

(Problems to be Solved by the Invention) As described above, a composite in which refractory metal fibers are embedded in a base containing Ni does not undergo a phase diffusion reaction at high temperatures of 800°C or higher, or during molding or heat treatment at such high temperatures. This causes the strength of the refractory metal fiber to deteriorate, and the refractory metal has a smaller coefficient of thermal expansion than other metals! a
Due to the thermal stress caused by the presence of fibers, sufficient strength cannot be obtained at high temperatures of 800° C. or higher, resulting in a lack of reliability.

This invention was made in consideration of these points,
The purpose is to obtain sufficiently high strength even when exposed to high temperatures,
Moreover, it is an object of the present invention to provide a heat-resistant composite that can be stably used over a long period of time, and a core metal, a bolt, a heater, and a magnetic composite using the same.

[Structure of the invention]

(Means and effects for solving the problems) The heat-resistant composite according to the present invention comprises a base ε made of a nickel-based or cobalt-based superalloy, a refractory metal fiber disposed in the base, and a niobium or niobium alloy. It has a two-layer structure of a niobium layer consisting of a niobium layer and a superalloy layer consisting of an iron-based superalloy that covers the niobium layer, and a coating layer that covers the refractory metal fiber. This composite is a flat plate-shaped NR
Ceramic, which is the a body, is used for core metals and columnar corners for turbine blades, as well as heat-resistant bolts, nuts, pins, and linear structures, as well as heat-resistant lobes and tubular structures. It can be used for pipes, etc.

Further, the magnetic composite according to the present invention includes a base made of a magnetic material throughout the body, a refractory metal fiber disposed in the base,
It is characterized by comprising a coating layer made of niobium or a niobium alloy and covering the refractory metal fiber.

Is the above heat resistant? The base material in j2 combination and the nickel-based or cobalt-based superalloy in 17 have a weight ratio of 5 to 3.
0% Cr, 5-20% Ag% 0.3-135% Y
, 0-30% Co5o-30% Fe and balance Ni
and 5-35% Cr, 5-20% 1.0.3-18.5% Y, 0-
A cobalt-based superalloy having a composition of 20% Ni and balance Co can be used to a large extent.

Moreover, the magnetic metal 4 as a base in the magnetic composite
1A materials include pure iron (>99.95% Fe), mild steel (
>99.5%Fe), magnetic steel (>99.5%Fe), silicon steel (Fe-1~3.5%Si), permalloy (Fe-
35-80% Ni), Alperm (Fe-10-16%
Metal/alloy materials such as Ag) can be used. Particularly, when a magnetic material containing a large amount of N i 4, such as permalloy, is used, a remarkable effect can be obtained.

The iron-based superalloy ε used as the coating layer of the refractory metal fibers may be any iron-based superalloy containing 20% or less of aluminum in terms of heavy engineering ratio. Specifically, 10-35% Cr, 5-20%
% Ag, balance Fe, or 20% or less Al, balance F
An iron-based superalloy consisting of e can be used.

Further, as the refractory metal fiber, a W wire, a Mo wire, a Ta wire, or a W wire containing at least one of The2, K, Si, and AJ7 can be used. In particular, T h 02
, Ks Si, and AN are preferred because they have sufficient strength and are difficult to cause re-condensation, which causes strength deterioration at high temperatures. The metal fiber has a diameter of 0.1 mu to 0.5+
A range of m+m is preferred. If the diameter is less than 0.1 mm, there will be inconvenience in handling;
If it exceeds , no improvement in strength can be expected.

Furthermore, the niobium layer and ultra-gold layer in the heat-resistant composite of the present invention and the niobium layer in the magnetic composite can be used at low pressure in an inert gas atmosphere of an argon gas shade without exposing the refractory metal fibers to high temperatures or oxidizing atmospheres. Preferably, it is formed by atmospheric plasma spraying.

According to the heat-resistant composite according to the present invention, the surface of the refractory metal fiber disposed in the base made of a Ni-based or Co-based superalloy is covered with a niobium layer and a superalloy layer made of an iron-based superalloy. These layers function as a barrier layer to prevent various elements from diffusing from the Ni-based or Co-based superalloy matrix (substrate) to the refractory metal fibers, thereby preventing deterioration of the refractory metal fibers. will be played. In addition, because Nb has a coefficient of thermal expansion between that of refractory metal fibers and Ni-based or Co-based superalloys, it can suppress thermal deformation when a thermal load is repeatedly applied between high temperature and room temperature. can. Therefore,
The heat-resistant composite of the present invention has sufficient strength even at high temperatures of 1000° C. or higher, is less likely to undergo thermal deformation, and has excellent high-temperature properties.

Further, according to the magnetic composite of the present invention, by covering the surface of the refractory metal fibers disposed in the base made of the magnetic metal with a niobium layer, various types of refractory metal fibers can be obtained from the magnetic metal as a matrix. The deterioration of the refractory metal fiber is prevented because it functions as a barrier layer that prevents the elements from diffusing.

Furthermore, since Nb has a coefficient of thermal expansion between that of refractory metal fibers and magnetic material metals, it is possible to suppress thermal deformation when a thermal load is repeatedly applied between high temperature and room temperature.

Therefore, the magnetic composite of the present invention has sufficient strength even when heat treated at a high temperature of 800°C or higher, and can maintain its strength even when used at a high temperature of about 500°C.

Next, a heater using the heat-resistant composite described above will be explained.

High-temperature heater materials used in electric furnaces include nichrome wire, platinum wire, tungsten wire, molybdenum wire, silicon knit, and the like. However, heaters using nichrome wire have a heating temperature of about 1000°C, and heating at higher temperatures requires oxidation, embrittlement, and embrittlement of the nichrome wire.
The lifespan will be shortened due to fusing, etc. A heater using a platinum wire can heat to a high temperature of 1,200 to 1,300°C, but platinum is a very expensive material, resulting in an expensive heater. Heaters using tungsten wires and molybdenum wires can perform high-temperature heating in a vacuum or in an inert gas atmosphere, but both tungsten wires and molybdenum wires quickly oxidize and break in the atmosphere, so they should not be used. I can't.

Furthermore, in a vacuum or in an inert gas atmosphere, the equipment becomes crowded and costs increase. Heaters using silicone knit are popular and can heat at high temperatures, but silicone knit is susceptible to thermal fatigue, and repeated heating and cooling can cause cracks and disconnection, shortening the lifespan of the heater. It is also weak against shock and will chip or break with the slightest impact.

On the other hand, the heater to which the above-mentioned heat-resistant composite is applied,
These shortcomings can be eliminated.

In other words, it has sufficient strength even when used for high-temperature heating of 1000°C or higher, and is difficult to cause thermal deformation.
It can be used stably at high temperatures for long periods of time and has excellent high temperature properties.

(Example) Examples of the present invention will be described below.

Example 1 First, a sample with a diameter of 0.3 containing 1.7 wt% The,
+am W wire (1,7 ThOz W wire) 30 wires with 0.
These W wires were lined up horizontally in a row at 15 mm intervals and fixed to a frame, and the surfaces of these W wires were sprayed with plasma spray in a low-pressure atmosphere to a thickness of 0.5 mm.
It was coated with a 03 mm Nb layer.

Subsequently, a 0.05 aos thick layer of 24 wt% C was deposited on this Nb layer by plasma spraying in the same manner as above.
Form a FeCrANYe gold layer with a composition of r, 8wt% A1, 0.5wt% Y, and the balance Fe, and fabricate a W wire covered with a Nb layer and a FeCrAQYe gold layer as a Fe-based superalloy layer. did. All of these 30 W lines were subjected to low-pressure plasma spraying, and 20 wt% of Co,
16wtq6 Cr, 13wt% Afi, 0.
N1CoAIY with a composition of 5 wt% Y and the balance Ni
Forming a metal layer, W/Nb/FeCrAgY/N1Co
An N1-based superalloy sheet having a structure of CrAj7Y and a thickness of 0.2 mm was produced.

Next, 10 of these sheets were stacked with a Ni-based brazing material sandwiched between them, and heat treated in a vacuum at 1200° C. for 15 minutes to obtain a heat-resistant composite containing about 30% by volume of W wire.

This heat-resistant composite was found to have a creep rupture strength of 1250 hours at 1100° C. under a load of 28 kg/+u+2. Also, between room temperature and 1100℃
Even after applying a heat load of more than 1,000 cycles, no protrusion occurred. Furthermore, even when heated at 1100° C. for 3000 hours, the W wires and Nb layer provided in the N1CoCrA and QY substrates did not oxidize.

As a comparative example, a Ni-based super-superalloy composite was prepared using a refractory metal fiber made of the same W wire covered with only an Nb layer as in the example and disposed in the same Ni-based superalloy as in the example. This heat-resistant composite can withstand a load of 5 kg/am2 at 800°C.
The creep rupture strength between 5I1.1 was H.

From the results of this comparative example, it is clear that the heat-resistant composite of the above example has N
It was confirmed that excellent high-temperature strength was achieved by being coated with a double layer of the B layer and the superalloy layer made of a Fe-based superalloy.

Example 2 Instead of the N1CoCrAj2Y substrate of Example 1, 2
4wt% Cr, 13wt% AD10.5wt% Y
A heat-resistant composite using a substrate made of N1CrAjlY having a composition of 1 and the remainder Ni was produced by the same manufacturing method as in Example 1.

As a result of measuring the properties of this heat-resistant composite, it was found that this fA-resistant composite had a creep rupture strength of 1200 hours under a load of 25 kg/112 at 1100°C. Furthermore, even when the same hot air 6:j as in Example 1 was applied to Ij, this heat-resistant composite did not have a protruding shape.

Example 3 Produced in the same manner as Example 1, W/Nb/FeCrARY
/NiCoCrAl Y, 1 height is 0.2
A Ni-based super-superalloy sheet with a thickness of 1 mm was obtained. Next, a plurality of these sheets were stacked together in the shape of a core with a Ni-based solder sandwiched between them, and heat treated in a vacuum at 1200°C for 15 minutes to form the sheets shown in Figures 1(a) and (b). The core metal for a ceramic gas turbine shown in the figure was obtained. FIG. 1(a) is a perspective view showing the hollow core bar 1, and FIG. 1(b) is an enlarged plan view showing the head mount I divided by circles in FIG. 1(a). be. In these figures, reference numeral 2 is a hollow portion, 3 is a W wire, 4 is a niobium layer, 5 is an iron-based superalloy layer, and 6 is a Ni-based superalloy substrate.

When the characteristics of this core metal were evaluated, it was found that it was 28K at 1100℃.
g/to the load of question 2 *11. ．． It was found that the creep rupture strength for 1250 hours was a. Also, room temperature and 1100
Even after being subjected to hot air bending, which was repeated more than 3,000 times between the temperature and the temperature, no protrusion occurred. Furthermore, at 1100℃ in the atmosphere,
Even after heating for 3000 hours, the W wires and Nb layer provided in the N1CoCrA and QY substrates were not oxidized.

Example 4 A W wire with a diameter of 0.3 mm containing 1.7 wt96 of The2 was fixed to a metal rod, and while rotating, the surface of the W wire was coated with Nb by low pressure atmosphere plasma spraying.
A Nb layer with a radius of 3 mm was formed. Subsequently, in a similar low-pressure atmosphere plasma melting step 1, FeCrA, 11! A refractory metal fiber of W/Nb/FeCrAj7Y was produced by coating Y alloy to a thickness of 0.1 m+m.

After filling the refractory metal fibers with a Fe-based brazing material and bundling them to a diameter of 5, the fibers were heated at 1 O00°C in a vacuum.
Heat treatment was performed for 5 minutes to obtain a refractory metal fiber bundle. The outer surface of this refractory metal fiber bundle was coated with N1CoCrAj7YA gold to a thickness of 0.5 mm by plasma spraying in a low-pressure atmosphere to obtain a cylindrical heat-resistant composite.

This heat-resistant composite was threaded to M5 to obtain a heat-resistant bolt shown in FIG. In Figure 2, reference 7 No. 7 is N
1JJ superalloy base, 8 is a W wire coated with an Nb layer and a superalloy layer, 9 is an Fe-based brazing material layer, and 10 is a threaded portion.

When the properties of this bolt were 3'F-valued, it was found that it had a creep rupture strength of 12,501 hours under a load of 28 kg/mm2 at 1,100°C. Further, even when subjected to a heat load of going back and forth between room temperature and 1100°C more than 3000 times, no deformation occurred. Furthermore, even if heated in the air at 1100°C for 3000 nj, N1Co
The W lines and the Nb layer provided in the CrANY substrate were not oxidized.

Similarly to this embodiment, a heat-resistant pin or nut having a structure in which a W wire coated with a Nb layer and a superalloy layer is disposed in a Ni-based or Co-based superalloy substrate can be manufactured.

Example 5 W wires prepared in the same manner as in Example 4, I, and iJ and coated with an Nb layer and a Fe-based super-superalloy layer were twisted together to form a lobe shape. The outer surface of this rope-shaped refractory metal fiber was coated with NiCoCrAgYi gold to a thickness of about 0.1 degrees by plasma spraying in a low-pressure atmosphere to produce the heat-resistant rope shown in FIG. 3.

In FIG. 3, reference numeral 11 is a Ni-based super-superalloy substrate;
12 is a W wire coated with a Nb layer and a superalloy layer.

When the characteristics of this heat-resistant lobe were evaluated, it was found that
It was found that the material had a creep rupture strength of 1250 hours under a load of 28 kg/l112.

Further, even when subjected to a heat load of going back and forth between the room temperature of 1100° C. and more than 3000 times, no deformation occurred.

Furthermore, even if heated in the air at 1100°C for 3000 hours, the W wires and Nb
The layer did not oxidize.

Example 6 Produced in the same manner as Example 1, W/Nb/FeCrA, l
) Y/N1CoCrA, lJ Y A Ni-based super superalloy sheet having a thickness of 0.2 mm was obtained.

Next, these 10 sheets were laminated in a stack with a Ni-based brazing filler metal between them, and heated in a vacuum at 1200°C for 15 minutes to form the heat-resistant pipe shown in Figure 4. was created. In FIG. 4, reference numeral 13 is a base of NIII alloy, 14 is a W wire coated with a Nb layer and a superalloy layer,
15 is a Ni-based brazing material layer.

When the characteristics of this heat-resistant pipe were evaluated, it was found that
It was found that the material had a creep rupture strength of 1250 hours under a load of 28 kg/am2. Further, even when subjected to hot air that cycled back and forth between room temperature and 1100° C. more than 3000 times, no deformation occurred. Furthermore, even if applied for 30,001 hours at 1,100°C in the air, N1CoCr
The W wire and Nb layer provided in the ANY substrate were not oxidized.

Example 7 A tungsten wire with a diameter of 0.3+Il+1 coated with 1.7% sodium oxide (The2) was coated with a niobium layer with a thickness of about 0.03 by low pressure plasma spraying.

This niobium layer was coated with 24wt% C by plasma spraying in a low-pressure atmosphere in the same manner as above to a thickness of 0.05mm.
An iron-based tiii gold having a composition of r, 3 wt% Aplo, 5 wt% Y1, balance Fe was coated. Furthermore, by low pressure atmosphere plasma spraying, it has a thickness of Oll + am,
20wt% Co, 16wt% Cr, 13wt% A
n).

W/Nb/FeCrAff formed by coating a nickel disordered superalloy having a composition of 0.5 wt% Y1 balance Ni
Y/N1CrAN Y configuration, diameter 0.56m
+* heat-resistant composite wire was produced.

Next, this heat-resistant composite wire was spirally wound 50 times at intervals of 1.5+l1 m on the outer surface of an alumina (Aff20i) tube having a diameter of 50III to produce a heater.

In the atmosphere, apply a voltage of 160V to this heater to
Electric heating was carried out to 300° C. and the heating was maintained for 5000 hours.

As a result, it was confirmed that there was no oxidation or embrittlement, and there was no disconnection, and that the wire was excellent in long nl IL'l use at high temperatures. Next, this heater was subjected to a repeated thermal load of energization heating (temperature raising) and cooling (between 1300°C and room temperature) for 10 minutes.
I gave it more than 00 times.

As a result, there was no heat-transferring, and no cracks or disconnections occurred.

Example 8 First, 30 W wires with a diameter of 0.3 axis (1,7 ThO2-W wire) containing 7 wt% of The2 were wired at 0.15 m.
They are lined up horizontally in a row at m intervals and fixed to a frame, and the surface of these W wires is coated with a 0.05 m thick layer by low pressure plasma spraying.
coated with a Nb layer of m.

The entire W wire coated with the Nb layer was subjected to low-pressure plasma spraying, and 45 wt% of Ni, 0.
An alloy layer having a composition of 3 wt % Mn with the remainder being Fe was formed, and the composition of W/Nb/Fe-Ni-Mn was H to produce a magnetic composite sheet with a thickness of 0.2 m+m. Next, 10 of these sheets were stacked with Fe7J brazing material sandwiched between them] 7. They were held in a vacuum at 1200°C and recrystallized for bonding and high magnetic permeability, resulting in a magnetic composite. I got a body.

This complex is 28 kg/mrs at 1100 °C
It was found that the material had a creep rupture strength of 1250 hours under a load of 2. Furthermore, even when subjected to a heat load of going back and forth between room temperature and 1100°C more than 3000 times, it did not change into a female shape. Furthermore, even when heated in the atmosphere at 1100° C. for 3000 hours, the W wires and Nb layer provided in the Fe-Ni-Mn substrate were not oxidized.

As a comparative example, a magnetic composite was produced in which the same W wire as in the example was disposed in a gold layer of magnetic material without being covered with an Nb layer. This magnetic composite had a creep rupture strength of H for 5 hours under a load of 5 kg/112 at 800°C.

From the results of this comparative example, it is clear that the magnetic composite material of the example has Nb
It was confirmed that due to the presence of the layer, it had excellent high temperature strength even after heat treatment at high temperature.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a heat-resistant composite that has sufficiently high strength at high temperatures and can be stably used over a long period of time, and a core metal, bolt, and heater using the same. Furthermore, it is possible to provide a magnetic composite material that has sufficiently high strength even after heat treatment at high temperatures and can be used stably for a long period of time.

[Brief explanation of drawings]

FIG. 1(a) is a perspective view showing a core metal for a ceramic gas turbine blade according to a third embodiment of the present invention, and FIG. 1(b) is an area I indicated by a circle in FIG. 1(a). FIG. 2 is a cross-sectional view showing a heat-resistant bolt according to a fourth embodiment of the present invention, and FIG. 3 is a cross-sectional view showing a heat-resistant rope according to a fifth embodiment of the present invention. FIG. 4 is a sectional view showing a heat-resistant vibrator according to a sixth embodiment of the present invention. 1... Core metal, 3, 8, 12.14... W wire, 4...
・Niobium layer, 5... Iron-based superalloy layer, 6, 7, 11.1
3... Base body, 9... Fe-based brazing material layer, 5... N-based brazing material layer.

Claims (7)

[Claims] (1) Consisting of a base made of a nickel-based or cobalt-based superalloy, a refractory metal fiber arranged in this base, a niobium layer made of niobium or a niobium alloy, and an iron-based superalloy covering the niobium layer. A heat-resistant composite having a two-layer structure of a superalloy layer, and comprising a coating layer that covers the refractory metal fiber. (2) Claim 1, wherein the base body is tubular.
The heat-resistant composite described in . (3) Claim 1, wherein the base body is linear.
The heat-resistant composite described in . (4) A core metal for a ceramic gas turbine blade, comprising the heat-resistant composite according to claim 1. (5) A heat-resistant bolt comprising the heat-resistant composite according to claim 1. (6) A heater comprising the heat-resistant composite according to claim 1. (7) A magnetic material comprising a base made of a magnetic metal material, refractory metal fibers disposed in the base, and a coating layer made of niobium or a niobium alloy and covering the refractory metal fibers. complex.