US3904382A - Corrosion-resistant coating for superalloys - Google Patents
Corrosion-resistant coating for superalloys Download PDFInfo
- Publication number
- US3904382A US3904382A US479853A US47985374A US3904382A US 3904382 A US3904382 A US 3904382A US 479853 A US479853 A US 479853A US 47985374 A US47985374 A US 47985374A US 3904382 A US3904382 A US 3904382A
- Authority
- US
- United States
- Prior art keywords
- coating
- alloy
- substrate
- corrosion
- mdc
- 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.)
- Expired - Lifetime
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/32—Selection of soldering or welding materials proper with the principal constituent melting at more than 1550 degrees C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3033—Ni as the principal constituent
- B23K35/304—Ni as the principal constituent with Cr as the next major constituent
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C19/00—Alloys based on nickel or cobalt
- C22C19/03—Alloys based on nickel or cobalt based on nickel
- C22C19/05—Alloys based on nickel or cobalt based on nickel with chromium
- C22C19/051—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W
- C22C19/052—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 40%
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C27/00—Alloys based on rhenium or a refractory metal not mentioned in groups C22C14/00 or C22C16/00
- C22C27/06—Alloys based on chromium
-
- 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
- C23C30/00—Coating with metallic material characterised only by the composition of the metallic material, i.e. not characterised by the coating process
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S428/00—Stock material or miscellaneous articles
- Y10S428/922—Static electricity metal bleed-off metallic stock
- Y10S428/923—Physical dimension
- Y10S428/924—Composite
- Y10S428/926—Thickness of individual layer specified
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12014—All metal or with adjacent metals having metal particles
- Y10T428/12028—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, etc.]
- Y10T428/12063—Nonparticulate metal component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12806—Refractory [Group IVB, VB, or VIB] metal-base component
- Y10T428/12826—Group VIB metal-base component
- Y10T428/12847—Cr-base component
- Y10T428/12854—Next to Co-, Fe-, or Ni-base component
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T428/00—Stock material or miscellaneous articles
- Y10T428/12—All metal or with adjacent metals
- Y10T428/12493—Composite; i.e., plural, adjacent, spatially distinct metal components [e.g., layers, joint, etc.]
- Y10T428/12771—Transition metal-base component
- Y10T428/12861—Group VIII or IB metal-base component
- Y10T428/12944—Ni-base component
Definitions
- This invention relates to the coating of a superalloy substrate with an oxidation and hot-corrosion resistant surface coating alloy composition comprising a nickel base alloy containing chromium and silicon which alloy will be referred to hereinafter as AME-2.
- Hot-corrosion resistance is required for applications in turbines burning natural gas or uncontaminated light distillates or in contaminated environments involving combusted diesel, heavy distillates or residual oils.
- the vacuum brazing time/temperature cycle used to apply the coating alloy to the substrate should be compatible with the normal heat treatment cycle for the substrate.
- Another object is to provide an alloy coating that melts, wets and flows uniformly at some temperature below the incipient melting point of the superalloy substrate.
- a further object is to provide an alloy which is metallurgically compatible with the substrate alloy and may be applied as a thick coating.
- the present invention relates to a coating alloy for a superalloy substrate having the following composition: Chromium 4565%, Silicon 5-1 2%, Nickel-balance. All compositions are given in weight percent.
- a nominal coating composition as proposed by applicant may comprise 45% Chromium, Silicon with the balance Nickel.
- silicon is beneficial for oxidation and hot corrosion resistance through the formation of SiO Silicon is used to control the melting and solidification behavior of the coating since the eutectic temperature in the pure Ni-Cr binary system occurs at 2450F which is too high for most nickel based superalloy substrates.
- the coating may be applied to the substrate by various methods including vacuum brazing, which is an established industrial technique.
- vacuum brazing which is an established industrial technique.
- other conventional methods of applying the coating alloy to the superalloy substrate could be used such as the slurry, aerosol spray or plasma spray plus heat treatment and transfer tape methods.
- some methods should be avoided such as the vapor deposition method which yields a coating microstructure oriented normal to the substrate surface, thus establishing potential shortcircuit diffusion paths e.g., grain boundaries, and growth defects for the introduction of corrodents such as sulphur and oxygen to the substrate.
- the resolidification structure of the subject vacuum brazed alloy is non-oriented, precluding this potential failure mode. Since the subject process involves the liquid and not the vapor state, greater segregation of the coating elements occurs.
- the present alloy takes advantage of this fact since the high chromium content produces a-Cr precipitate particles dispersed in y-solid solution nickel matrix containing a high chromium level.
- the lower melting point Ni1Si eutectic phase is equally well dispersed throughout the coating during solidification.
- a coating alloy was prepared using a nominal alloy composition comprised of 45% Chromium, 10% Silicon and the balance Nickel. Other compositions may be used falling within the range, supra.
- the substrate was prepared by mechanical abrading or by chemical cleaning plus electroplating a 0.2 to 1.0 mil layer of nickel thereon.
- the alloy used is in the form of a powder and is fabricated into a brazing transfer tape.
- the tape is comprised of 2OO +325 mesh powder, held together with about 5% of an organic binder on a plastic backing sheet.
- a template of the desired shape to fit the substrate is cut from the transfer tape. The plastic backing is removed and the tape applied to the substrate.
- the coated part is then subjected to the vacuum brazing cycle.
- the vacuum brazing cycle is controlled to permit outgassing of the binder at about 700 to 1000F, to minimize contamination of the coating and substrate.
- the optimum vacuum brazing cycle consists of heating the alloy to a temperature of about 2075F for about 5 minutes followed by argon gas cooling. Generally no finishing treatments are required, since the as-brazed coated surface yields a surface finish in the 35 to 60 microinch (RMS) range.
- the part may receive a final heat treatment to develop the mechanical properties of the subtaining brittle intermetallic compounds, such as sigma and carbides.
- the microstructure of the subject alloy contains a mixture of 'y-Ni matrix, a-Cr precipitate particles, and NizSi eutectic.
- the precise composition and morphology of these phases depend both on the starting compositions of the subject alloy powder and substrate alloy, as well as the subsequent brazing and heat treatment cycles.
- the corrosion resistance of the subject alloy is derived from the high bulk Cr content (i.e. 45%) of the coating, but more specifically, it is due to the a-Cr particles and the high Cr, 'y-Ni matrix, which constitute a very significant portion of the coated structure. Since the coating is applied in the liquid state and resolidified, elements from the substrate are easily incorporated into the coating.
- the brazing cycle time and temperature
- time and temperature can be utilized to control the morphology and composition of the coating to some extent.
- Nickel base superalloys have been coated in the temperature range 2060 to 2130F, with time-at-temperature between 2 and minutes.
- Lower brazing temperatures are not preferred due to AMB-2s melting characteristics.
- Higher brazing temperatures can be used depending upon the heating and cooling rates, the equipment used and other considerations.
- Specific superalloy substrates may even re quire higher temperatures; however, the optimum parameters for the reference alloys is 2075F for 5 minutes. In general, the higher the temperature, the shorter the time, to prevent excessive fiow, reaction, and interdiffusion with the substrate.
- One feature of the subject alloy coating in the as-coated condition is its lack of a complex diffusion zone between the coating and substrate.
- conventional aluminide coatings are characterized by a finger-like diffusion zone con-
- the non-oriented structure of the subject alloy is due to the nature of the melting and re-solidification process. Segregation of the elements and resulting precipitates is related to composition, heat input during brazing, and cooling conditions.
- Line-of-sight vapordeposited coatings such as the MCrAlYs deposited by electron beam evaporation, generally grow normal tothe substrate surface. Grain growth is, therefore, nor mal to the substrate, hence, growth defects are also oriented. Growth defects, when they occur in the subject alloy, are non-oriented solidification defects.
- Oxidation/hot-corrosion testing have been conducted under simulated gas turbine condition in a small combustion burner rig.
- a controlled atmosphere was produced by combusting doped diesel oil containing 1% S, to which artificial sea salt was mixed to produce 8 ppm Na in the combustion products.
- the rigs were run at I600F, at an air:fuel ratio of 60:1 with a gas velocity of 70 fps.
- the specimens were removed and air-blasted to room temperature every hours to simulate turbine shutdown and to promote oxide and- /or coating spallation under severe thermal cycling conditions. This is the most conditions test condition utilized to simulate a hot-corrosion operating environment.
- AMB-2 was braze-coated on IN-738 using techniques previously described, and compared to available commercial aluminide coatings applied to IN-738. Results were obtained by sectioning the specimens, and metallographically determining at 100 times magnification the maximum depth of corrosion penetration through the coating and substrate, the average bulk coating surface loss, as well as an approximation of the area percent coating remaining. The results, listed in Table I below show the clear superiority of AME-2 over conventional aluminide coatings.
- (l)RT2l-Niv;kel has: alloy ufChrum-alloy American Corp. contains l7-35'.( Al. 0l0 Cr, balance Ni and 5'71 of other incidental elements.
- pack concentration the commercial process used for applying conventional aluminide coatings, known as pack concentration, has technical and economic limitations which restrict aluminide thickness to approximately 3 mils and somewhat less on Co-base superalloys. Since pack cementation is basically a vapor deposition process, applied thickness is timedependent. AME-2, however, can be applied up to about mils thickness, with no change in the time/- temperature vacuum brazing cycle. These data in Table I show that the aluminide coatings tested were essentially fully penetrated after just 600 to 1000 hours, with virtually no coating remaining. In many cases, significant corrosion of the IN-738 substrate resulted from the destruction of the coating.
- AMB-2 can be applied in thicknesses up to about 10 mils, as stated above, with no change required in the technique or time/temperature parameters used in its application.
- AME-2 offers both a more corrosion resistant alloy composition and increased coating thickness, both of which result in a longer life.
- the coating alloy of claim 1 consisting essentially Letters Patent 9 the Umted 'f 4. of 45% chromium 10% silicon and the'balance nickel.
- An oxidation and corrosion resistant composite The alloy of Claim 1 wherein the microstructure comprising a superalloy substrate and a coating alloy Contains a mixture f 'y-Ni m trix, a-Cr precipitate parbonded thereto consisting essentially of the following tides and ;s eutectk;
Abstract
An oxidation and hot corrosion resistant alloy for coating a superalloy substrate. The surface coating composition comprises a nickel base alloy containing chromium and silicon.
Description
Elite ttes atent 11 1 Beltran et al. Sept. 9, 1975 [54] CORROSION-RESISTANT COATING FOR 3,155,491 11/1964 Hoppin ct al. 75 171 x 3,649,225 3/l972 Simmons 29/194 3,754,968 8/1973 Reznik 29 194 x [75] Inventors: Adri n M- B l r m- Lake; 3,810,754 Ford et al. 75 171 Norman R. Lindblad, Schenectady; Gerald E. Wasielewski, Rexford, all of N.Y.
Assignee: General Electric Company,
Schenectady, NY.
Filed: June 17, 1974 Appl. No.: 479,853
US. Cl 29/194; 75/134 F; 75/176 Int. Cl. B32B 15/04 Field of Search 29/194; 75/176, 171, 134 F References Cited UNITED STATES PATENTS l/ 1962 Stephenson 29/194 Primary ExaminerL. Dewayne Rutledge Assistant Examiner E. L. Weise Attorney, Agent, or Firm-John F. Ahern; James W. Mitchell 1 71 ABSTRACT An oxidation and hot corrosion resistant alloy for coating a superalloy substrate. The surface coating composition comprises a nickel base alloy containing chromium and silicon.
4 Claims, N0 Drawings CORROSION-RESISTANT COATING FOR SUPERALLOYS BACKGROUND OF THE INVENTION This invention relates to the coating of a superalloy substrate with an oxidation and hot-corrosion resistant surface coating alloy composition comprising a nickel base alloy containing chromium and silicon which alloy will be referred to hereinafter as AME-2.
Hot-corrosion resistance is required for applications in turbines burning natural gas or uncontaminated light distillates or in contaminated environments involving combusted diesel, heavy distillates or residual oils.
Many protective alloy coatings for superalloy substrates are shown by the prior art. These coatings include the conventional aluminide coatings which have technical limitations which restrict the coating thickness resulting in an early deterioration of the coatings and further do not exhibit the superior hot corrosion resistance properties of the subject alloy coating, especially in a hot-corrosion operating environment. The subject coating alloy is also more economical in its initial processing than the alloys of the prior art. The field repair of components removed from service is simple and more economical since selected areas can be recoated without need to mask or protect areas not requiring additional coating, as is the case of packaluminide or electron beam vapor deposited coatings.
In considering alloy coating compositions for superalloy substrates it was discovered that the alloy must exhibit the following characteristics:
1. Must be oxidation and hot-corrosion resistant over the temperature range l400 to about 2000F.
2. Must melt, wet and flow uniformly at some temperature below the incipient melting point of the superalloy substrate. Ideally, the vacuum brazing time/temperature cycle used to apply the coating alloy to the substrate should be compatible with the normal heat treatment cycle for the substrate.
3. Must be metallurgically stable, and compatible with the substrate alloy.
SUMMARY OF THE INVENTION It is therefore, an object of my invention to provide a superalloy with a coating alloy which is oxidation and hot-corrosion resistant over a temperature range.
Another object is to provide an alloy coating that melts, wets and flows uniformly at some temperature below the incipient melting point of the superalloy substrate.
A further object is to provide an alloy which is metallurgically compatible with the substrate alloy and may be applied as a thick coating.
Briefly stated, the present invention relates to a coating alloy for a superalloy substrate having the following composition: Chromium 4565%, Silicon 5-1 2%, Nickel-balance. All compositions are given in weight percent. A nominal coating composition as proposed by applicant may comprise 45% Chromium, Silicon with the balance Nickel.
It is known that high Cr levels are the most effective deterrent to hot corrosion caused by Na and S- bearing atmospheres in the temperature range 14001800F. At these temperatures, greater than about 36% Cr is required to generate a-Cr precipitate. However, it should be noted that the content of chromium should not be too high since the coating may become brittle over the range recited. The embrittlement is caused by the formation of excessive amounts of hard, body centered cubic a-Cr precipitate.
Similarly, silicon is beneficial for oxidation and hot corrosion resistance through the formation of SiO Silicon is used to control the melting and solidification behavior of the coating since the eutectic temperature in the pure Ni-Cr binary system occurs at 2450F which is too high for most nickel based superalloy substrates.
The coating may be applied to the substrate by various methods including vacuum brazing, which is an established industrial technique. However, other conventional methods of applying the coating alloy to the superalloy substrate could be used such as the slurry, aerosol spray or plasma spray plus heat treatment and transfer tape methods. However, some methods should be avoided such as the vapor deposition method which yields a coating microstructure oriented normal to the substrate surface, thus establishing potential shortcircuit diffusion paths e.g., grain boundaries, and growth defects for the introduction of corrodents such as sulphur and oxygen to the substrate. The resolidification structure of the subject vacuum brazed alloy is non-oriented, precluding this potential failure mode. Since the subject process involves the liquid and not the vapor state, greater segregation of the coating elements occurs. The present alloy takes advantage of this fact since the high chromium content produces a-Cr precipitate particles dispersed in y-solid solution nickel matrix containing a high chromium level. The lower melting point Ni1Si eutectic phase is equally well dispersed throughout the coating during solidification.
Those parts of the present invention which are considered to be new are set forth in detail in the claims appended hereto. The invention, however, may be better understood and the advantage appreciated from a detailed description as follows:
DETAILED DESCRIPTION A coating alloy was prepared using a nominal alloy composition comprised of 45% Chromium, 10% Silicon and the balance Nickel. Other compositions may be used falling within the range, supra. The substrate was prepared by mechanical abrading or by chemical cleaning plus electroplating a 0.2 to 1.0 mil layer of nickel thereon. The alloy used is in the form of a powder and is fabricated into a brazing transfer tape. The tape is comprised of 2OO +325 mesh powder, held together with about 5% of an organic binder on a plastic backing sheet. A template of the desired shape to fit the substrate is cut from the transfer tape. The plastic backing is removed and the tape applied to the substrate.
Additional liquid brazing cement may be needed to firmly adhere the tape in place. The coated part is then subjected to the vacuum brazing cycle. The vacuum brazing cycle is controlled to permit outgassing of the binder at about 700 to 1000F, to minimize contamination of the coating and substrate. The optimum vacuum brazing cycle consists of heating the alloy to a temperature of about 2075F for about 5 minutes followed by argon gas cooling. Generally no finishing treatments are required, since the as-brazed coated surface yields a surface finish in the 35 to 60 microinch (RMS) range. The part may receive a final heat treatment to develop the mechanical properties of the subtaining brittle intermetallic compounds, such as sigma and carbides.
The nominal alloy compositions of the superalloy substrates to which our coating is applied are listed in Table A as follows:
Table A Nominal Alloy Compositions of superalloy Substrates Alloy Ni Co Cr Al Ti Mo Cb Tu B Zr IN-738 Ba]. 8.5 16 3.4 3.4 1.75 2.6 0.9 1.75 0.01 0.04 0.1 1 lN-792 Hal. 9 12.5 3.5 4.1 1.9 4 (0.5 HT) 4 0.015 0.013 0.13 Rene '77 B111. 14 4.3 3.4 4.2 0.016 0.04 0.07 Rene '80 Ball. 95 14 3 0 5.0 4.0 4.0 N 0.015 0.03 0.17 MM-509 10 Ba]. 23.5 0.2 7 3.5 0.5 06
treatment sequence for the specific substrate alloy.
In the as-solidified condition, the microstructure of the subject alloy contains a mixture of 'y-Ni matrix, a-Cr precipitate particles, and NizSi eutectic. The precise composition and morphology of these phases depend both on the starting compositions of the subject alloy powder and substrate alloy, as well as the subsequent brazing and heat treatment cycles. The corrosion resistance of the subject alloy is derived from the high bulk Cr content (i.e. 45%) of the coating, but more specifically, it is due to the a-Cr particles and the high Cr, 'y-Ni matrix, which constitute a very significant portion of the coated structure. Since the coating is applied in the liquid state and resolidified, elements from the substrate are easily incorporated into the coating. Hence, the brazing cycle (time and temperature) can be utilized to control the morphology and composition of the coating to some extent. Nickel base superalloys have been coated in the temperature range 2060 to 2130F, with time-at-temperature between 2 and minutes. Lower brazing temperatures are not preferred due to AMB-2s melting characteristics. Higher brazing temperatures can be used depending upon the heating and cooling rates, the equipment used and other considerations. Specific superalloy substrates may even re quire higher temperatures; however, the optimum parameters for the reference alloys is 2075F for 5 minutes. In general, the higher the temperature, the shorter the time, to prevent excessive fiow, reaction, and interdiffusion with the substrate. High temperatures and/or longer brazing times promote large a-Cr particles, less NizSi eutectic but greater interdiffusion with the substrate. Lower temperatures and time produce smaller, better dispersed a-Cr particles and NizSi eutectic, with little substrate interdiffusion. One feature of the subject alloy coating in the as-coated condition is its lack of a complex diffusion zone between the coating and substrate. By contrast, conventional aluminide coatings are characterized by a finger-like diffusion zone con- The non-oriented structure of the subject alloy is due to the nature of the melting and re-solidification process. Segregation of the elements and resulting precipitates is related to composition, heat input during brazing, and cooling conditions. Line-of-sight vapordeposited coatings, such as the MCrAlYs deposited by electron beam evaporation, generally grow normal tothe substrate surface. Grain growth is, therefore, nor mal to the substrate, hence, growth defects are also oriented. Growth defects, when they occur in the subject alloy, are non-oriented solidification defects.
As previously stated, the subject alloy coating for a superalloy substrate has exhibited superior hot corrosion resistant properties over other prior art coated superalloys. Oxidation/hot-corrosion testing have been conducted under simulated gas turbine condition in a small combustion burner rig. A controlled atmosphere was produced by combusting doped diesel oil containing 1% S, to which artificial sea salt was mixed to produce 8 ppm Na in the combustion products. The rigs were run at I600F, at an air:fuel ratio of 60:1 with a gas velocity of 70 fps. The specimens were removed and air-blasted to room temperature every hours to simulate turbine shutdown and to promote oxide and- /or coating spallation under severe thermal cycling conditions. This is the most conditions test condition utilized to simulate a hot-corrosion operating environment.
In a first test AMB-2 was braze-coated on IN-738 using techniques previously described, and compared to available commercial aluminide coatings applied to IN-738. Results were obtained by sectioning the specimens, and metallographically determining at 100 times magnification the maximum depth of corrosion penetration through the coating and substrate, the average bulk coating surface loss, as well as an approximation of the area percent coating remaining. The results, listed in Table I below show the clear superiority of AME-2 over conventional aluminide coatings.
Table I Bulk Max. Surface S b tr te Penetration Loss, 7r. Coating Alloy Coating Fuel Temp. "F Time-Hr. Mils Mils Remaining IN-738 AME-2 D.O.+S.S. 1600 620 3.3 3.3
(HRT-Zl 1012 6.9 1.1 NA
(2)MDC1 307 6.5 0.5 0
Table I-Continued Bulk Max. Surface Substrate Penetration Loss, /r Coating Alloy Coating Fuel Temp. F Time-Hr. Mils Mils Remaining (3)MDC-9 635 4.5 1.6 60
I274 9.8 4.2 NA
NA-Not analyzed.
(l)RT2l-Niv;kel has: alloy ufChrum-alloy American Corp. contains l7-35'.( Al. 0l0 Cr, balance Ni and 5'71 of other incidental elements.
(I )MD('-I-Nick cl base allo of Howmct ('urp. contains l7-35Ci Al. balance nickel and up to 107: of other incidental elements. (3 )MDC LNickcl base alloy of Howmet Corp. contains 17-35); AI. 0-l0 Cr. billulice nickel and 5?! of other incidental elements.
It is important to note that the commercial process used for applying conventional aluminide coatings, known as pack concentration, has technical and economic limitations which restrict aluminide thickness to approximately 3 mils and somewhat less on Co-base superalloys. Since pack cementation is basically a vapor deposition process, applied thickness is timedependent. AME-2, however, can be applied up to about mils thickness, with no change in the time/- temperature vacuum brazing cycle. These data in Table I show that the aluminide coatings tested were essentially fully penetrated after just 600 to 1000 hours, with virtually no coating remaining. In many cases, significant corrosion of the IN-738 substrate resulted from the destruction of the coating.
The data in Table I further shows that a substantial portion of AME-2 remains after 2000 hours of testing.
This is due, in part, to the fact that AMB-2 can be applied in thicknesses up to about 10 mils, as stated above, with no change required in the technique or time/temperature parameters used in its application. Hence, AME-2 offers both a more corrosion resistant alloy composition and increased coating thickness, both of which result in a longer life.
Another series of burner rig tests were conducted on AMB 2 coated Rene-77, (See Table II below) and compared to conventional aluminide coatings. Some of the tests were run in an undoped natural gas atmosphere, which produces a normal oxidizing environture, or (2) the thermal treatment required to apply and stabilize the coating is incompatible with the substrates heat treatment, hence degrading its mechanical properties.
In Table III, standard 0.252 inch diameter as-cast test bars of Rene-77 and IN-738 were braze coated with AME-2, and tensile and rupture tested. The results are compared in Table III with aluminide-coated bars of these two alloys. Each coating/alloy combination was given the full heat treatment previously found optimal for that system. The data shows that the room temperature tensile properties of both IN-738 and Rene-77 are least affected by AME-2. Yield strengths are 10 to 15% higher than the aluminide coatings, with only slightly less ductility. The latter is due in part to the greater thickness of AMB-2.
Table II Mils Thickness Alloy Coating Substrate Coating Fuel Temp. F Time-Hr. Remaining Rene-77 AMB2 Diesel Oil Sea Salt I600 2483 3.3 MDC-I I600 [35 0 MDC-9 I 600 I 200 2.6 AMB-Z I800 31 4.5 MDC- I I800 600 1.2 MDC-9 I800 00 3.0 AME-2 Natural Gas I800 I I I0 4.2 MDC-l I800 I000 1.5 MDC-9 I 800 I000 3.0 AME-2 Natural Gas I900 I008 3.7 MDC-I I900 I000 1.5 MDC-9 I900 I000 3.0
Table 111 Mechanical Properties of Coated Alloys A) Tensile Properties (70F) Alloy Coating UTS-ksi 0.2 Y.S.. ksi 0.02 Y.S.. ksi 7! El /t RA Rene-77 None 136.5 1 12.0 105.5 9.0 12.4 AME-2 135.5 1 14.3 102.0 5.8 4.0 MDC-l 123.0 102.2 86.0 5.0 12.5 MDC9 1 17.0 101.0 87.0 4.0 8.6 lN-738 AME-2 142.5 121.0 105.0 4.3 6.3 MDC-l 146.2 1082 93.2 5.3 8.7 MDC-9 154.8 104.8 92.0 9.2 13.6 B) Stress Rupture Stress Temp. Time Alloy Coating ksi Hr. "/z El. /1 Ra P* lN-738 AMB-Z 15 1800 386.8 12.6 36.0 51.0 MDC-1 15 1800 215.9 25.4 32.2 50.5 MDC-9 15 1800 283.9 24.9 32.0 50.7 Rcne77 AME-2 15 1750 484.7 5.7 7.2 50.1
MDC-l 15 1800 235.3 5.4 10 6 50.6 MDC-9 1800 150.2 5.8 1 6 50.1
*Where P T log t) X 10" in stress-rupture at lXO0F/l5 ksi. AMBJ also produces superior results on 1N-738. For Rene-77. the parameter P shows that AMB-Z is at least equivalent to aluminide coating MDC-9. It is necessary to use the Larson-Miller parameter for comparison. since AMB-2 was tested at 2i different temperature.
What is claimed as new and desired to be secured by 2. The coating alloy of claim 1 consisting essentially Letters Patent 9 the Umted 'f 4. of 45% chromium 10% silicon and the'balance nickel. 1. An oxidation and corrosion resistant composite The alloy of Claim 1 wherein the microstructure comprising a superalloy substrate and a coating alloy Contains a mixture f 'y-Ni m trix, a-Cr precipitate parbonded thereto consisting essentially of the following tides and ;s eutectk;
l m si Weight Percenti 4. The coating alloy of claim 1 wherein the thickness Chr m 40-65% of the alloy coating composition for the superalloy may S111con 54 range up to 10 mils. Nickel Balance
Claims (4)
1. AN OXIDATION AND CORROSION RESISTANT COMPOSITE COMPRISING A SUPERALLOY SUBSTRATE AND A COATING ALLOY BONDED THERETO CONSISTING ESSENTIALLY OF THE FOLLOWING ELEMENTS IN WEIGHT PERCENT: CHROMIUM - 40-65% SILICON - 5-12% NICKEL - BALANCE
2. The coating alloy of claim 1 consisting essentially of 45% chromium 10% silicon and the balance nickel.
3. The alloy of claim 1 wherein the microstructure contains a mixture of gamma -Ni matrix, Alpha -Cr precipitate particles and Ni:Si eutectic.
4. The coating alloy of claim 1 wherein the thickness of the alloy coating composition for the superalloy may range up to 10 mils.
Priority Applications (9)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US479853A US3904382A (en) | 1974-06-17 | 1974-06-17 | Corrosion-resistant coating for superalloys |
GB17603/75A GB1507564A (en) | 1974-06-17 | 1975-04-28 | Alloys |
CA226,882A CA1038114A (en) | 1974-06-17 | 1975-05-14 | Corrosion-resistant coating for superalloys |
IT24193/75A IT1038831B (en) | 1974-06-17 | 1975-06-10 | CORROSION RESISTANT COATING FOR SUPER ALLOYS |
DE19752526779 DE2526779A1 (en) | 1974-06-17 | 1975-06-16 | CORROSION-RESISTANT COATING FOR ALLOYS |
NO752126A NO139970C (en) | 1974-06-17 | 1975-06-16 | COMPOSITE OBJECT OF A SUPER-ALLOY SUPPORT AND A COATING ALLOY BOUND TO THE SUPER-ALLOY SUPPLY |
JP7210875A JPS5524497B2 (en) | 1974-06-17 | 1975-06-16 | |
NL7507214A NL7507214A (en) | 1974-06-17 | 1975-06-17 | PROCESS FOR PREPARING AN OXIDATION AND CORROSION RESISTANT MATERIAL, AS WELL AS MADE FROM THIS MATERIAL. |
FR7518832A FR2274701A1 (en) | 1974-06-17 | 1975-06-17 | NICKEL-BASED COATING FOR SUPERALLOYS AND PARTS THUS OBTAINED |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US479853A US3904382A (en) | 1974-06-17 | 1974-06-17 | Corrosion-resistant coating for superalloys |
Publications (1)
Publication Number | Publication Date |
---|---|
US3904382A true US3904382A (en) | 1975-09-09 |
Family
ID=23905709
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US479853A Expired - Lifetime US3904382A (en) | 1974-06-17 | 1974-06-17 | Corrosion-resistant coating for superalloys |
Country Status (9)
Country | Link |
---|---|
US (1) | US3904382A (en) |
JP (1) | JPS5524497B2 (en) |
CA (1) | CA1038114A (en) |
DE (1) | DE2526779A1 (en) |
FR (1) | FR2274701A1 (en) |
GB (1) | GB1507564A (en) |
IT (1) | IT1038831B (en) |
NL (1) | NL7507214A (en) |
NO (1) | NO139970C (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4369233A (en) * | 1978-07-21 | 1983-01-18 | Elbar B.V., Industrieterrien "Spikweien" | Process to apply a protecting silicon containing coating on specimen produced from superalloys and product |
US4743514A (en) * | 1983-06-29 | 1988-05-10 | Allied-Signal Inc. | Oxidation resistant protective coating system for gas turbine components, and process for preparation of coated components |
US4774149A (en) * | 1987-03-17 | 1988-09-27 | General Electric Company | Oxidation-and hot corrosion-resistant nickel-base alloy coatings and claddings for industrial and marine gas turbine hot section components and resulting composite articles |
EP0381819A1 (en) * | 1989-02-07 | 1990-08-16 | Detlev Dr. Repenning | Tool for processing elastomeres |
WO1992003241A1 (en) * | 1990-08-28 | 1992-03-05 | Liburdi Engineering, U.S.A. Inc. | Powder metallurgy repair technique |
US5577655A (en) * | 1994-11-30 | 1996-11-26 | The Morgan Crucible Company Plc | Flexible metal-containing tapes or films and associated adhesives |
US6409795B2 (en) * | 1996-04-10 | 2002-06-25 | General Electric Company | Coating methods, coating products and coated articles |
US6416596B1 (en) | 1974-07-17 | 2002-07-09 | The General Electric Company | Cast nickel-base alloy |
US6440238B1 (en) * | 1999-08-09 | 2002-08-27 | Alstom (Switzerland) Ltd | Process for treating the surface of a component, made from a Ni based superalloy, to be coated |
US6541075B2 (en) * | 1999-05-03 | 2003-04-01 | General Electric Company | Method for forming a thermal barrier coating system |
WO2004072312A2 (en) * | 2003-02-11 | 2004-08-26 | The Nanosteel Company | Highly active liquid melts used to form coatings |
US20080245445A1 (en) * | 2007-04-04 | 2008-10-09 | David Andrew Helmick | Process for forming a chromium diffusion portion and articles made therefrom |
US20100021289A1 (en) * | 2002-05-10 | 2010-01-28 | General Electric Company | Method for applying a NiA1 based coating by an electroplating technique |
CN108473828A (en) * | 2015-12-21 | 2018-08-31 | 德莎欧洲股份公司 | The transition zone with security feature of lateral edges for adhesive tape |
CN114540766A (en) * | 2022-03-15 | 2022-05-27 | 陕西理工大学 | Nano-size metal W film/NiTi composite board and preparation method thereof |
CN114752932A (en) * | 2022-05-12 | 2022-07-15 | 山东科技大学 | Directional solidification high-bearing coating and preparation method thereof |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB8605878D0 (en) * | 1986-03-10 | 1986-04-16 | Johnson Matthey Plc | Casting transition metal alloy |
JPS6331535A (en) * | 1986-07-23 | 1988-02-10 | Jgc Corp | Apparatus for treating carbon-containing compound having carbon precipitation suppressing property |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3015880A (en) * | 1957-11-12 | 1962-01-09 | Power Jets Res & Dev Ltd | Corrosion resistant treatment of metal articles |
US3155491A (en) * | 1961-12-26 | 1964-11-03 | Gen Electric | Brazing alloy |
US3649225A (en) * | 1969-11-17 | 1972-03-14 | United Aircraft Corp | Composite coating for the superalloys |
US3754968A (en) * | 1971-09-10 | 1973-08-28 | Wiant Corp De | Process for producing errosion and wear resistant metal composites |
US3810754A (en) * | 1973-03-16 | 1974-05-14 | Olin Corp | Oxidation resistant nickel base alloys |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE808687C (en) * | 1948-10-02 | 1951-07-19 | Artur Beyerlein | Wall patterning device |
-
1974
- 1974-06-17 US US479853A patent/US3904382A/en not_active Expired - Lifetime
-
1975
- 1975-04-28 GB GB17603/75A patent/GB1507564A/en not_active Expired
- 1975-05-14 CA CA226,882A patent/CA1038114A/en not_active Expired
- 1975-06-10 IT IT24193/75A patent/IT1038831B/en active
- 1975-06-16 DE DE19752526779 patent/DE2526779A1/en not_active Withdrawn
- 1975-06-16 NO NO752126A patent/NO139970C/en unknown
- 1975-06-16 JP JP7210875A patent/JPS5524497B2/ja not_active Expired
- 1975-06-17 FR FR7518832A patent/FR2274701A1/en active Granted
- 1975-06-17 NL NL7507214A patent/NL7507214A/en not_active Application Discontinuation
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3015880A (en) * | 1957-11-12 | 1962-01-09 | Power Jets Res & Dev Ltd | Corrosion resistant treatment of metal articles |
US3155491A (en) * | 1961-12-26 | 1964-11-03 | Gen Electric | Brazing alloy |
US3649225A (en) * | 1969-11-17 | 1972-03-14 | United Aircraft Corp | Composite coating for the superalloys |
US3754968A (en) * | 1971-09-10 | 1973-08-28 | Wiant Corp De | Process for producing errosion and wear resistant metal composites |
US3810754A (en) * | 1973-03-16 | 1974-05-14 | Olin Corp | Oxidation resistant nickel base alloys |
Cited By (28)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6416596B1 (en) | 1974-07-17 | 2002-07-09 | The General Electric Company | Cast nickel-base alloy |
US6428637B1 (en) | 1974-07-17 | 2002-08-06 | General Electric Company | Method for producing large tear-free and crack-free nickel base superalloy gas turbine buckets |
US4369233A (en) * | 1978-07-21 | 1983-01-18 | Elbar B.V., Industrieterrien "Spikweien" | Process to apply a protecting silicon containing coating on specimen produced from superalloys and product |
US4743514A (en) * | 1983-06-29 | 1988-05-10 | Allied-Signal Inc. | Oxidation resistant protective coating system for gas turbine components, and process for preparation of coated components |
US4774149A (en) * | 1987-03-17 | 1988-09-27 | General Electric Company | Oxidation-and hot corrosion-resistant nickel-base alloy coatings and claddings for industrial and marine gas turbine hot section components and resulting composite articles |
EP0284793A2 (en) * | 1987-03-17 | 1988-10-05 | General Electric Company | Oxidation-and hot corrosion-resistant nickel-base alloy coatings and claddings for industrial and marine gas turbine hot section components and resulting composite articles |
EP0284793A3 (en) * | 1987-03-17 | 1989-10-11 | General Electric Company | Oxidation-and hot corrosion-resistant nickel-base alloy coatings and claddings for industrial and marine gas turbine hot section components and resulting composite articles |
EP0381819A1 (en) * | 1989-02-07 | 1990-08-16 | Detlev Dr. Repenning | Tool for processing elastomeres |
WO1992003241A1 (en) * | 1990-08-28 | 1992-03-05 | Liburdi Engineering, U.S.A. Inc. | Powder metallurgy repair technique |
US5156321A (en) * | 1990-08-28 | 1992-10-20 | Liburdi Engineering Limited | Powder metallurgy repair technique |
US5577655A (en) * | 1994-11-30 | 1996-11-26 | The Morgan Crucible Company Plc | Flexible metal-containing tapes or films and associated adhesives |
US6409795B2 (en) * | 1996-04-10 | 2002-06-25 | General Electric Company | Coating methods, coating products and coated articles |
US6541075B2 (en) * | 1999-05-03 | 2003-04-01 | General Electric Company | Method for forming a thermal barrier coating system |
US6440238B1 (en) * | 1999-08-09 | 2002-08-27 | Alstom (Switzerland) Ltd | Process for treating the surface of a component, made from a Ni based superalloy, to be coated |
US20100021289A1 (en) * | 2002-05-10 | 2010-01-28 | General Electric Company | Method for applying a NiA1 based coating by an electroplating technique |
WO2004072312A2 (en) * | 2003-02-11 | 2004-08-26 | The Nanosteel Company | Highly active liquid melts used to form coatings |
WO2004072312A3 (en) * | 2003-02-11 | 2005-04-14 | Nanosteel Co | Highly active liquid melts used to form coatings |
CN100427625C (en) * | 2003-02-11 | 2008-10-22 | 纳米钢公司 | Highly active liquid melts used to form coatings |
US20040250926A1 (en) * | 2003-02-11 | 2004-12-16 | Branagan Daniel James | Highly active liquid melts used to form coatings |
US8070894B2 (en) | 2003-02-11 | 2011-12-06 | The Nanosteel Company, Inc. | Highly active liquid melts used to form coatings |
US20080245445A1 (en) * | 2007-04-04 | 2008-10-09 | David Andrew Helmick | Process for forming a chromium diffusion portion and articles made therefrom |
US8262812B2 (en) * | 2007-04-04 | 2012-09-11 | General Electric Company | Process for forming a chromium diffusion portion and articles made therefrom |
US9222164B2 (en) | 2007-04-04 | 2015-12-29 | General Electric Company | Process for forming a chromium diffusion portion and articles made therefrom |
CN108473828A (en) * | 2015-12-21 | 2018-08-31 | 德莎欧洲股份公司 | The transition zone with security feature of lateral edges for adhesive tape |
CN114540766A (en) * | 2022-03-15 | 2022-05-27 | 陕西理工大学 | Nano-size metal W film/NiTi composite board and preparation method thereof |
CN114540766B (en) * | 2022-03-15 | 2023-07-25 | 陕西理工大学 | Nanometer-sized metal W film/NiTi composite board and preparation method thereof |
CN114752932A (en) * | 2022-05-12 | 2022-07-15 | 山东科技大学 | Directional solidification high-bearing coating and preparation method thereof |
CN114752932B (en) * | 2022-05-12 | 2023-07-18 | 山东科技大学 | Directional solidification high-bearing coating and preparation method thereof |
Also Published As
Publication number | Publication date |
---|---|
NO139970B (en) | 1979-03-05 |
NO139970C (en) | 1979-06-13 |
JPS5524497B2 (en) | 1980-06-30 |
FR2274701B1 (en) | 1977-07-22 |
DE2526779A1 (en) | 1976-01-02 |
NO752126L (en) | 1975-12-18 |
FR2274701A1 (en) | 1976-01-09 |
IT1038831B (en) | 1979-11-30 |
JPS5113335A (en) | 1976-02-02 |
NL7507214A (en) | 1975-12-19 |
CA1038114A (en) | 1978-09-12 |
GB1507564A (en) | 1978-04-19 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US3904382A (en) | Corrosion-resistant coating for superalloys | |
US4080486A (en) | Coating system for superalloys | |
US5549767A (en) | Heat treatment and repair of cobalt base superalloy articles | |
Lindblad | A review of the behavior of aluminide-coated superalloys | |
US5316866A (en) | Strengthened protective coatings for superalloys | |
US3955935A (en) | Ductile corrosion resistant chromium-aluminum coating on superalloy substrate and method of forming | |
US5238752A (en) | Thermal barrier coating system with intermetallic overlay bond coat | |
US3676085A (en) | Cobalt base coating for the superalloys | |
US5240491A (en) | Alloy powder mixture for brazing of superalloy articles | |
US4070507A (en) | Platinum-rhodium-containing high temperature alloy coating method | |
US4910098A (en) | High temperature metal alloy mixtures for filling holes and repairing damages in superalloy bodies | |
KR100474467B1 (en) | Nickel Brazing Material | |
US3849865A (en) | Method of protecting the surface of a substrate | |
JPS6136061B2 (en) | ||
US5712050A (en) | Superalloy component with dispersion-containing protective coating | |
US4326011A (en) | Hot corrosion resistant coatings | |
US5182080A (en) | Advanced high-temperature brazing alloys | |
US3598638A (en) | Diffusion metallic coating method | |
US4024294A (en) | Protective coatings for superalloys | |
US3748110A (en) | Ductile corrosion resistant coating for nickel base alloy articles | |
US20020098294A1 (en) | Method of providing a protective coating on a metal substrate, and related articles | |
US4371570A (en) | Hot corrosion resistant coatings | |
US4144380A (en) | Claddings of high-temperature austenitic alloys for use in gas turbine buckets and vanes | |
JP3875973B2 (en) | Protective coating | |
US3928029A (en) | Braze alloy system |