CA2138255A1 - Process for producing a protective coating on metal walls subject to attack by hot gases, especially flue gases - Google Patents
Process for producing a protective coating on metal walls subject to attack by hot gases, especially flue gasesInfo
- Publication number
- CA2138255A1 CA2138255A1 CA002138255A CA2138255A CA2138255A1 CA 2138255 A1 CA2138255 A1 CA 2138255A1 CA 002138255 A CA002138255 A CA 002138255A CA 2138255 A CA2138255 A CA 2138255A CA 2138255 A1 CA2138255 A1 CA 2138255A1
- Authority
- CA
- Canada
- Prior art keywords
- powder
- walls
- protective coating
- plasma
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
- C23C4/134—Plasma spraying
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
- B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
- B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
- B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
- B05B7/22—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/02—Pretreatment of the material to be coated, e.g. for coating on selected surface areas
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
- C23C4/04—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the coating material
- C23C4/10—Oxides, borides, carbides, nitrides or silicides; Mixtures thereof
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Plasma & Fusion (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Electromagnetism (AREA)
- Coating By Spraying Or Casting (AREA)
- Laminated Bodies (AREA)
- Chemical Vapour Deposition (AREA)
- Investigating, Analyzing Materials By Fluorescence Or Luminescence (AREA)
- Application Of Or Painting With Fluid Materials (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A process for producing a protective coating on walls subject to attack by hot gases in a predetermined temperature range, which are made of metal and a predetermined basic material, in combustion plants, heat exchangers or similar installations, in which a powder of metallic, carbide, oxycarbide or silicide materials or mixtures thereof are applied to the metal walls using the plasma jet process. The invention proposes that: a) the surface of the wall is roughened; b) the basic material of the wall is activated;
and c) immediately afterwards the powder is applied at room temperature and in atmospheric conditions by the plasma jet process; being d) the composition of the powder selected beforehand so that the stress as a function of the temperature in the unstressed state (at room temperature) found with the aid of coefficients of heat expansion of the basic material and test-pieces for the transition region between the basic material and the applied coating produced from various powders gives tensile stresses of between 50 and 800 N/mm2 and preferably between 500 and 800 N/mm2, which is reduced to 0 or exhibits slight compression stresses in the predetermined temperature range.
A process for producing a protective coating on walls subject to attack by hot gases in a predetermined temperature range, which are made of metal and a predetermined basic material, in combustion plants, heat exchangers or similar installations, in which a powder of metallic, carbide, oxycarbide or silicide materials or mixtures thereof are applied to the metal walls using the plasma jet process. The invention proposes that: a) the surface of the wall is roughened; b) the basic material of the wall is activated;
and c) immediately afterwards the powder is applied at room temperature and in atmospheric conditions by the plasma jet process; being d) the composition of the powder selected beforehand so that the stress as a function of the temperature in the unstressed state (at room temperature) found with the aid of coefficients of heat expansion of the basic material and test-pieces for the transition region between the basic material and the applied coating produced from various powders gives tensile stresses of between 50 and 800 N/mm2 and preferably between 500 and 800 N/mm2, which is reduced to 0 or exhibits slight compression stresses in the predetermined temperature range.
Description
.~ ~13~a A Process for Producing a Protective Coating on Metallic Walls Exposed to Hot Gases, Particularly Flue Gasses -., ''.
The present invention relates to a process for producing ;
a protective coating on walls of metal base material that are exposed to hot gases, particularly flue gases , in combustion plants or heat exchangers, in which a powder of metallic, . . .
carbide, oxide ceramic, or silicide materials, or mixtures thereof, are`applied to the previously cleaned metallic walls to form a protective layer.
Such protective coatings are to be applied, for example, ~ ~;
to the cooling walls of heat recuperators in steel-converter plants. These cooling walls are subject to extremely high ~ ~ `
stresses. Flue gases that are at a temperature of approximately 1400C - 1800C and are loaded with ashes and slag particles flow along one side, whilst the saturated steam pressures on the other side are at approximately 20 - 80 bar, the tubular walls that are cooled by saturated steam having ;
internal-pressure gradients of up to 2 bar/min.
DE 23 55 532 C2 describes a process for powder-deposition ;;~
welding of metal~ and alloys on a preheated metal surface that ~ ; , has been prepared by sand-blasting, in which said metal ~-surface has been previously heated to at least 100C to approximately 650C. Both during deposition welding by means of rod electrodes and in powder deposition welding or flame ~praying with subseguentimelting down, the base material is -;
heated to a very high temperature during application of the protecti~e coating, and this results in an undesirable mlcro~tructural change. In particular, during flame spraying, the melting-down temperature is between 980C and 1060C, depending on the spraying powder that is used. In addition, ~''.'' -` ~ 1 3 ~
the high heat input causes distortion of the walls that are to :~
be coated, and this can then resu].t in problems and additional costs ;~ .
' ~ ,'' v . ', ""',"',",.', ~ ~'.:'''.'''''`'''`
la '~:
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when these walls are installed, because of dimensional inaccuracy. If the protective coatings are applied -subsequently, using these known processes, the stresses that ;-are caused by the temperatures cannot react in the form of distortion, but will result in cracks in the surfaces of the walls that are installed, particularly in the areas of the welds. In the case of deposition welding, the protective layer is from approximately 8mm to 10 mm thick, and lmm to 2 mm thick in the case of flame spraying.
DE-AS 26 30 507 discloses a process for producing protective coatings against hot-gas corrosion and/or mechanical wear on work pieces, in which a coating powder consisting of different alloys is applied to the work piece by plasma spraying in a vacuum. In this vacuum spraying process, . . .
a vacuum has to be created and the coating has to be applied ~ ;
in a treatment chamber that is not accessible from outside, and this results in considerable expense. This is not possible, for example, in the case of large walls of the sort that ha~e to be installed in heat recuperators.
It is the task of the present invention to propose a ~ ;
~peclfic process of this kind, in which the above problems do not occur and, in particular, avoids distortion of the work pieces and stresses that can result in cracks.
The solution to this problem is set out in the description in Claim I. ~The,seqondary claims 2 to 8 describe useful complementary steps in the process.
In the process according to the present invention, not only is the surface of the walls roughened before the powder is applied with the atmospheric plasma-jet techni~ue, but the ~:
~ , . - .
.... :.
:-. -.. ,"
, .
~ ~ 3 ~
base material of the walls is also activated with electro-corundum in such a way that disturbances in the metallic -lattice, which increase the adhesive forces, are also produced. Then, immediately after this activation, before these disturbances in the lattice have been neutralized again, the powder is applied onto the walls, under atmospheric conditions, by the plasma jet technique, the surface of the walls meanwhile keeping approximately room temperature.
The composition of the powder is selected in accordance with ,~ `
the respective base material and the future service conditions, in particular the specified temperature ranges.
According to the invention, the transition zone between base ~ . ;, material and coating applied shall have, in unstrained :~
condition, that is to say, at ambient temperature, tensile ~tres~es between 50 and 800 N/mm2, preferably between 500 and : :,. ~,"
800 N/mm2, which in the specified temperature range have been :~ ;:
reduced to zero, or show minor compressive strains. These , , . ~: -:
: ' . '.
.: ::
'"`;'''' ' ' ~"'' 2a ~ ~
' ' .~ . ' ''' ' ~'`'''' ~8~5j ::
states of stress (see enclosed figure) are calculated by means of the therrnal expansion coefFicients of the base material on the one side, and of test pieces made of difFerent powders, on the other. This calculation can then be checked pursuant to DIN 50121.
The prooess according to the invention allows a protective coating against hot gas corrosion and/or mechanical wear and tear, which is insensitive to thermal shock and easily reparable, to be produced, for instanoe, on plane or arched walls of combustion plants and heat exchangers, especially heat recuperators in steel converter plants.
.:.,~ ' '.''"'.' "'"`, ' It has tumed out that a final coating thickness of 0.1 to 0.5 mm, preferably 0.15 to 0.25 -~
mm, is already sufFicient for preventing appreciable wear and tear for a much longer period than it has so far been possible.We would like to point out in this connection that an 80 KW
plasma jet installation with internal powder feeding has proved to be particularly suited for 1 applying such a protective coating, the powder used having a grain size of less than 75 ,um, preferabiy 20 to 40 ,um. The said powder particulariy allows a very thin coating to be applied which meets the requirements of insensitivity to themmal shock and resistance to hot gas corroslon and avolds high intemal stress owing to Hs process-inherent laminar ~ 9 8tructure. It is most advantageous to produce the total protective coating in at least t~o pa88~s, ~ -Be~bre plasma spraying, the wall surFaces to be coated can be roughened and activated with speclal fusec alumina, preferably with high-purity white special fused alurnina.
It hss further tumed out to be advantageous that in the process according to the invention the surFace be only heated to approx. 40 C, maximum 60 C, by the plasma jet and the powcier particles contained in the same. Thus distortion of the walls can in particular be precluded.
It l~ advisable to use a nickel alloy containing powder. ~ ~;
It ha~ turne~t out that atmospheric plasrna spraying should be carried out not later than 45 minutes, preferabiy not later than 30 minutes, after activation of the wall su face, `
13 ~ a Finally, the stress temperature of the walls provided with the said protective coating may range between 300 and 1800 C, preferably between 600 and 1000 C.
The stressnemperature diagram of the enclosed figure shows exemplarily the stress behaviour in the transition zone between base material and protectiYe coating in the temperature range between 0 ~C and approximately 1200 C. The diagram is based on the measured average linear thermal 0xpansion coefficients of the two materials. In unstressed condition, the coated wall of a converter heat recuperator shows tensile stresses of more than 600 N/mm2 in the transition zone between the base material and the coating material.
, ~ ., .
While the recuperator is in operation, the protective coating on the wall is suddenly exposed to the high temperatures of the steel melt and the slag spurting from the converter. The diagram illustrates this process on the basis of the stress development: The neutral range is ;~ -at about 700 C while, above 700 C, compressive stresses preventing breaking away of or cracWng in the protective coating are building up in the transHion zone. Owing to the usually .
water-cooled tubes of the recuperator walls, the state of tensile stress is then slowly restored, that is to say that, in the diagram, the plotted line representing the stress developmerlt 18 pa6sed through in oppo6He direction. The figure shows oniy an exemplary str~s dr~lopment as a function of the temperature. For other stress ranges, the so called zero ~tate may certalnly appear at ~iO0 C or at 800 C instead of at 700 QC.
''',,',''`'"','",''"~
" .` .`"'""',''`, ', ,,:,,'" ~ ,, ..,,,,,",`,~
" ' '' ''''''' ' '' 4 ::
The present invention relates to a process for producing ;
a protective coating on walls of metal base material that are exposed to hot gases, particularly flue gases , in combustion plants or heat exchangers, in which a powder of metallic, . . .
carbide, oxide ceramic, or silicide materials, or mixtures thereof, are`applied to the previously cleaned metallic walls to form a protective layer.
Such protective coatings are to be applied, for example, ~ ~;
to the cooling walls of heat recuperators in steel-converter plants. These cooling walls are subject to extremely high ~ ~ `
stresses. Flue gases that are at a temperature of approximately 1400C - 1800C and are loaded with ashes and slag particles flow along one side, whilst the saturated steam pressures on the other side are at approximately 20 - 80 bar, the tubular walls that are cooled by saturated steam having ;
internal-pressure gradients of up to 2 bar/min.
DE 23 55 532 C2 describes a process for powder-deposition ;;~
welding of metal~ and alloys on a preheated metal surface that ~ ; , has been prepared by sand-blasting, in which said metal ~-surface has been previously heated to at least 100C to approximately 650C. Both during deposition welding by means of rod electrodes and in powder deposition welding or flame ~praying with subseguentimelting down, the base material is -;
heated to a very high temperature during application of the protecti~e coating, and this results in an undesirable mlcro~tructural change. In particular, during flame spraying, the melting-down temperature is between 980C and 1060C, depending on the spraying powder that is used. In addition, ~''.'' -` ~ 1 3 ~
the high heat input causes distortion of the walls that are to :~
be coated, and this can then resu].t in problems and additional costs ;~ .
' ~ ,'' v . ', ""',"',",.', ~ ~'.:'''.'''''`'''`
la '~:
" ,Z
when these walls are installed, because of dimensional inaccuracy. If the protective coatings are applied -subsequently, using these known processes, the stresses that ;-are caused by the temperatures cannot react in the form of distortion, but will result in cracks in the surfaces of the walls that are installed, particularly in the areas of the welds. In the case of deposition welding, the protective layer is from approximately 8mm to 10 mm thick, and lmm to 2 mm thick in the case of flame spraying.
DE-AS 26 30 507 discloses a process for producing protective coatings against hot-gas corrosion and/or mechanical wear on work pieces, in which a coating powder consisting of different alloys is applied to the work piece by plasma spraying in a vacuum. In this vacuum spraying process, . . .
a vacuum has to be created and the coating has to be applied ~ ;
in a treatment chamber that is not accessible from outside, and this results in considerable expense. This is not possible, for example, in the case of large walls of the sort that ha~e to be installed in heat recuperators.
It is the task of the present invention to propose a ~ ;
~peclfic process of this kind, in which the above problems do not occur and, in particular, avoids distortion of the work pieces and stresses that can result in cracks.
The solution to this problem is set out in the description in Claim I. ~The,seqondary claims 2 to 8 describe useful complementary steps in the process.
In the process according to the present invention, not only is the surface of the walls roughened before the powder is applied with the atmospheric plasma-jet techni~ue, but the ~:
~ , . - .
.... :.
:-. -.. ,"
, .
~ ~ 3 ~
base material of the walls is also activated with electro-corundum in such a way that disturbances in the metallic -lattice, which increase the adhesive forces, are also produced. Then, immediately after this activation, before these disturbances in the lattice have been neutralized again, the powder is applied onto the walls, under atmospheric conditions, by the plasma jet technique, the surface of the walls meanwhile keeping approximately room temperature.
The composition of the powder is selected in accordance with ,~ `
the respective base material and the future service conditions, in particular the specified temperature ranges.
According to the invention, the transition zone between base ~ . ;, material and coating applied shall have, in unstrained :~
condition, that is to say, at ambient temperature, tensile ~tres~es between 50 and 800 N/mm2, preferably between 500 and : :,. ~,"
800 N/mm2, which in the specified temperature range have been :~ ;:
reduced to zero, or show minor compressive strains. These , , . ~: -:
: ' . '.
.: ::
'"`;'''' ' ' ~"'' 2a ~ ~
' ' .~ . ' ''' ' ~'`'''' ~8~5j ::
states of stress (see enclosed figure) are calculated by means of the therrnal expansion coefFicients of the base material on the one side, and of test pieces made of difFerent powders, on the other. This calculation can then be checked pursuant to DIN 50121.
The prooess according to the invention allows a protective coating against hot gas corrosion and/or mechanical wear and tear, which is insensitive to thermal shock and easily reparable, to be produced, for instanoe, on plane or arched walls of combustion plants and heat exchangers, especially heat recuperators in steel converter plants.
.:.,~ ' '.''"'.' "'"`, ' It has tumed out that a final coating thickness of 0.1 to 0.5 mm, preferably 0.15 to 0.25 -~
mm, is already sufFicient for preventing appreciable wear and tear for a much longer period than it has so far been possible.We would like to point out in this connection that an 80 KW
plasma jet installation with internal powder feeding has proved to be particularly suited for 1 applying such a protective coating, the powder used having a grain size of less than 75 ,um, preferabiy 20 to 40 ,um. The said powder particulariy allows a very thin coating to be applied which meets the requirements of insensitivity to themmal shock and resistance to hot gas corroslon and avolds high intemal stress owing to Hs process-inherent laminar ~ 9 8tructure. It is most advantageous to produce the total protective coating in at least t~o pa88~s, ~ -Be~bre plasma spraying, the wall surFaces to be coated can be roughened and activated with speclal fusec alumina, preferably with high-purity white special fused alurnina.
It hss further tumed out to be advantageous that in the process according to the invention the surFace be only heated to approx. 40 C, maximum 60 C, by the plasma jet and the powcier particles contained in the same. Thus distortion of the walls can in particular be precluded.
It l~ advisable to use a nickel alloy containing powder. ~ ~;
It ha~ turne~t out that atmospheric plasrna spraying should be carried out not later than 45 minutes, preferabiy not later than 30 minutes, after activation of the wall su face, `
13 ~ a Finally, the stress temperature of the walls provided with the said protective coating may range between 300 and 1800 C, preferably between 600 and 1000 C.
The stressnemperature diagram of the enclosed figure shows exemplarily the stress behaviour in the transition zone between base material and protectiYe coating in the temperature range between 0 ~C and approximately 1200 C. The diagram is based on the measured average linear thermal 0xpansion coefficients of the two materials. In unstressed condition, the coated wall of a converter heat recuperator shows tensile stresses of more than 600 N/mm2 in the transition zone between the base material and the coating material.
, ~ ., .
While the recuperator is in operation, the protective coating on the wall is suddenly exposed to the high temperatures of the steel melt and the slag spurting from the converter. The diagram illustrates this process on the basis of the stress development: The neutral range is ;~ -at about 700 C while, above 700 C, compressive stresses preventing breaking away of or cracWng in the protective coating are building up in the transHion zone. Owing to the usually .
water-cooled tubes of the recuperator walls, the state of tensile stress is then slowly restored, that is to say that, in the diagram, the plotted line representing the stress developmerlt 18 pa6sed through in oppo6He direction. The figure shows oniy an exemplary str~s dr~lopment as a function of the temperature. For other stress ranges, the so called zero ~tate may certalnly appear at ~iO0 C or at 800 C instead of at 700 QC.
''',,',''`'"','",''"~
" .` .`"'""',''`, ', ,,:,,'" ~ ,, ..,,,,,",`,~
" ' '' ''''''' ' '' 4 ::
Claims (8)
1. A process for producing a protective coating on walls that are of a metallic base material and are exposed to hot gases, in particular flue gases, preferably such walls in heat recuperators or heat exchangers, in which a powder of metallic, carbide, oxide ceramic, or silicide materials, or mixtures thereof, is applied to the previously cleaned metallic walls the help of a plasma spraying process so as to form the protective coating, characterized in that a) the surface of the walls is roughened and activated by high-purity electro-corundum and b) the powder is applied immediately after, at room temperature and under atmospheric conditions, using the plasma-spraying process, c) the composition of the powder being so pre-selected that the stress as a function of the temperature in the non-stressed state (at room temperature), determined-- with the help of the coefficient of thermal expansion of the base material and of test pieces produced from different powders the tension determined--for the transition area between the base material and the applied coating results in tensile stresses between 50 and 800 Nm/mm2, preferably between 500°C and 800°C which, in the temperature range from 300°C and 1800°C that is provided and claimed, preferably 600°C to 1000°C, is essentially decreased to 0, or else displays lower compressive strains.
2. A process as defined in Claim 1, characterized in that the protective coating that is applied has a final thickness from 0.1 to 0.5 mm, preferably from 0.15 to 0.25 mm.
3. A process as defined in Claim 1 or Claim 2, characterized in that the protective coating is applied with an 80KW
plasma-spraying apparatus with an interior powder-feed system.
plasma-spraying apparatus with an interior powder-feed system.
4. A process as defined in at least one of the Claims 1 to 3, characterized in that powder used for applying the protective coating has a grain size of less than 75µm, preferably 20 to 40µm.
5. A process as defined in at least one of the Claims 1 to 4, characterized in that the protective coating is produced in at least two transition processes.
6. A process as defined in at least one of the preceding claims, characterized in that the surface of the walls is heated to only approximately 45°C, and at most 60°C by the plasma jet with the molten powder particles contained therein.
7. A process as defined in at least one of the preceding claims, characterized in that a powder containing a nickel alloy is used.
8. A process as defined in Claim 1, characterized in that the atmospheric plasma coating is carried out at the latest 45 minutes, preferably at the latest 30 minutes, after activation of the surface of the walls.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4220063.6 | 1992-06-19 | ||
| DE4220063A DE4220063C1 (en) | 1992-06-19 | 1992-06-19 | Process for producing a protective layer on metallic walls exposed to hot gases, in particular flue gases |
| PCT/EP1993/001483 WO1994000616A1 (en) | 1992-06-19 | 1993-06-11 | Process for producing a protective coating on metal walls subject to attack by hot gases, especially flue gases |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2138255A1 true CA2138255A1 (en) | 1994-01-06 |
Family
ID=6461363
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002138255A Abandoned CA2138255A1 (en) | 1992-06-19 | 1993-06-11 | Process for producing a protective coating on metal walls subject to attack by hot gases, especially flue gases |
Country Status (14)
| Country | Link |
|---|---|
| EP (1) | EP0672197B1 (en) |
| JP (1) | JP3150697B2 (en) |
| KR (1) | KR950701983A (en) |
| AT (1) | ATE178364T1 (en) |
| AU (1) | AU672009B2 (en) |
| BR (1) | BR9306566A (en) |
| CA (1) | CA2138255A1 (en) |
| CZ (1) | CZ313794A3 (en) |
| DE (2) | DE4220063C1 (en) |
| ES (1) | ES2132237T3 (en) |
| PL (1) | PL171965B1 (en) |
| RU (1) | RU2107744C1 (en) |
| SK (1) | SK156394A3 (en) |
| WO (1) | WO1994000616A1 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0727504A3 (en) * | 1995-02-14 | 1996-10-23 | Gen Electric | Plasma coating process for improved bonding of coatings on substrates |
| AT411625B (en) * | 2000-04-28 | 2004-03-25 | Vaillant Gmbh | Heat exchanger, especially a coiled tube heat exchanger of a water heater, is coated using a plasma stream containing added silicon dioxide, aluminum oxide, silicon compound and-or titanium compound |
| CZ298780B6 (en) * | 2003-12-23 | 2008-01-23 | Koexpro Ostrava, A. S. | Protective coating of tools and implements for preventing formation of mechanical incentive sparks |
| DE102007020420B4 (en) | 2007-04-27 | 2011-02-24 | Häuser & Co. GmbH | Plasma spraying process for coating superheater pipes and using a metal alloy powder |
| DE102013010126B4 (en) | 2013-06-18 | 2015-12-31 | Häuser & Co. GmbH | Plasmapulverspritzverfahren and apparatus for coating panels for boiler walls in conjunction with a laser beam device |
| CN108101062A (en) * | 2018-01-17 | 2018-06-01 | 江苏中能硅业科技发展有限公司 | A kind of preparation process of polycrystalline silicon reducing furnace and its furnace tube inner wall functional layer |
| JP7370793B2 (en) | 2019-09-30 | 2023-10-30 | セコム株式会社 | security equipment |
| JP7370794B2 (en) | 2019-09-30 | 2023-10-30 | セコム株式会社 | security equipment |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2213350B1 (en) * | 1972-11-08 | 1975-04-11 | Sfec | |
| US3911891A (en) * | 1973-08-13 | 1975-10-14 | Robert D Dowell | Coating for metal surfaces and method for application |
| DE2630507C3 (en) * | 1976-07-07 | 1983-12-15 | MTU Motoren- und Turbinen-Union München GmbH, 8000 München | Process for the production of protective layers on workpieces and device for carrying out the process |
| US4075392A (en) * | 1976-09-30 | 1978-02-21 | Eutectic Corporation | Alloy-coated ferrous metal substrate |
| US4588607A (en) * | 1984-11-28 | 1986-05-13 | United Technologies Corporation | Method of applying continuously graded metallic-ceramic layer on metallic substrates |
| JP2695835B2 (en) * | 1988-05-06 | 1998-01-14 | 株式会社日立製作所 | Ceramic coated heat resistant material |
| DE3815436A1 (en) * | 1988-05-06 | 1989-11-16 | Muiden Chemie B V | DRIVE CHARGES FOR LARGE-CALIBRED BULLETS |
| DE3821658A1 (en) * | 1988-06-27 | 1989-12-28 | Thyssen Guss Ag | Process for producing corrosion-resistant and wear-resistant layers on printing press cylinders |
| CA2053928A1 (en) * | 1990-10-24 | 1992-04-25 | Toshihiko Hashimoto | Benzopyran derivatives having anti-hypertensive and vasodilartory activity, their preparation and their therapeutic use |
-
1992
- 1992-06-19 DE DE4220063A patent/DE4220063C1/en not_active Expired - Fee Related
-
1993
- 1993-06-11 RU RU94046201A patent/RU2107744C1/en active
- 1993-06-11 ES ES93912953T patent/ES2132237T3/en not_active Expired - Lifetime
- 1993-06-11 SK SK1563-94A patent/SK156394A3/en unknown
- 1993-06-11 DE DE59309491T patent/DE59309491D1/en not_active Expired - Lifetime
- 1993-06-11 JP JP50198994A patent/JP3150697B2/en not_active Expired - Fee Related
- 1993-06-11 KR KR1019940704599A patent/KR950701983A/en not_active Application Discontinuation
- 1993-06-11 AT AT93912953T patent/ATE178364T1/en not_active IP Right Cessation
- 1993-06-11 AU AU43250/93A patent/AU672009B2/en not_active Ceased
- 1993-06-11 BR BR9306566A patent/BR9306566A/en not_active IP Right Cessation
- 1993-06-11 PL PL93306721A patent/PL171965B1/en not_active IP Right Cessation
- 1993-06-11 WO PCT/EP1993/001483 patent/WO1994000616A1/en active IP Right Grant
- 1993-06-11 CZ CZ943137A patent/CZ313794A3/en unknown
- 1993-06-11 CA CA002138255A patent/CA2138255A1/en not_active Abandoned
- 1993-06-11 EP EP93912953A patent/EP0672197B1/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| AU672009B2 (en) | 1996-09-19 |
| RU2107744C1 (en) | 1998-03-27 |
| EP0672197A1 (en) | 1995-09-20 |
| AU4325093A (en) | 1994-01-24 |
| DE59309491D1 (en) | 1999-05-06 |
| RU94046201A (en) | 1996-10-20 |
| PL171965B1 (en) | 1997-07-31 |
| WO1994000616A1 (en) | 1994-01-06 |
| CZ313794A3 (en) | 1995-08-16 |
| KR950701983A (en) | 1995-05-17 |
| SK156394A3 (en) | 1997-02-05 |
| BR9306566A (en) | 1999-01-12 |
| ATE178364T1 (en) | 1999-04-15 |
| EP0672197B1 (en) | 1999-03-31 |
| JPH08501350A (en) | 1996-02-13 |
| JP3150697B2 (en) | 2001-03-26 |
| ES2132237T3 (en) | 1999-08-16 |
| DE4220063C1 (en) | 1993-11-18 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued |