Classifications

• • 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
  • C22C19/055—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 20% but less than 30%
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B15/00—Layered products comprising a layer of metal
  • B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
  • B32B15/013—Layered products comprising a layer of metal all layers being exclusively metallic one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium
  • B32B15/015—Layered products comprising a layer of metal all layers being exclusively metallic one layer being formed of an iron alloy or steel, another layer being formed of a metal other than iron or aluminium the said other metal being copper or nickel or an alloy thereof
• • 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
  • C22C19/058—Alloys based on nickel or cobalt based on nickel with chromium without Mo and W
• • 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
• • 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
  • Y10T428/12931—Co-, Fe-, or Ni-base components, alternative to each other
• • 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
  • Y10T428/12937—Co- or Ni-base component next to Fe-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

• COMPOSITE METAL PRODUCTS [75] Inventors: Roy Gwyn Faulkner, Stourbridge;
• ABSTRACT A composite product comprising a foundation alloy containing Ni to 45%, Cr 15 to 25%, C up to 0.1%, titanium and/or niobium in a total of about from 1 to 4%, Al 0 to 4%, M00 to 10%, balance Fe, clad with an alloy containing Cr 45 to 60%, C up to 0.04%, Zr 0.1 to 4%, balance Ni.
• An intermediate layer of nickel can be included between the foundation and the cladding.
• the present invention relates to composite metal products and, more particularly, composite products comprising a high strength foundation alloy clad with a corrosion-resistant alloy (or cladding alloy), which alloys are metallurgically bonded.
• the tubes in the super-heater possess both gOOd high temperature strength and good corrosion resistance to super-heated steam and hot flue gases.
• two dissimilar alloys are in metallurgically bonded contact, as in the case of such composites at high temperatures, e.g., greater than 600C., for long periods of time, interdifiusion of the major elements across the interface between the respective alloys can occur.
• the respective alloy compositions of the two component members may be changed, thereby changing their respective properties and/or there may be an undesirable accumulation or depletion of certain elements in the region of the interface which may cause embrittlement and failure.
• An object of the present invention is to provide a composite product exhibitinggood high temperature strength and corrosion resistance and exhibiting minimal interdiffusion.
• a composite product comprises a foundation member of an alloy containing, by weight from about to about-45 percent nickel; from about to about percent chromium; less than about 0.01 percent free carbon (i.e., carbon that is not limited to within the acceptable distance of 5 to pm from the interface between the alloys after exposure at temperatures up to about 700C. for times of up to 1,000 hours.
• free carbon i.e., carbon that is not limited to within the acceptable distance of 5 to pm from the interface between the alloys after exposure at temperatures up to about 700C. for times of up to 1,000 hours.
• the zirconium addition in the cladding alloy will w foundation alloy, then this element will tend to diffuse across the interface between the foundation and the cladding, into the cladding, thereby deleteriously affecting the efficacy of the zirconium in mitigating diffusion of major elements by tying up free zirconium.
• a minimum carbon content of about 0.01 percent is preferred in the foundation alloy to provide sufficient strength at high temperatures.
• carbon in the cladding alloy should be avoided and the carbon content thereof must not exceed 0.04 percent.
• the total carbon content of the foundation alloy preferably does not exceed 0.07 percent and in addition a strong carbide forming element such as titanium or niobium or both, must be present therein in a total 25 amount of about from 1 percent to 4 percent.
• Other strong carbide forming elements which may be used are tantalum and vanadium. 1
• the nickel content of the foundation alloy should be at least 10 percent to ensure adequate strength. However, when the nickel content exceeds 45 percent, chromium carbides tend to form in preference to titanium or niobium carbides. This is because the titanium and niobium form Ni Ti and Ni Nb, respectively. Chromium carbides are not as stable as either titanium 3 5 carbide or niobium carbide and are therefore less effective in combining with the free carbon in the alloys.
• the chromium content ,of the foundation alloy must be at least 15 percent to ensure adequate corrosion resistance. However, amounts of chromium above 25 40 percent could lead to embrittlement by the formation of sigma phase. 1
• Aluminum strengthens the foundation alloys and up to 4 percent thereof may be present for this purpose.
• the aluminum content is between about 1 and 4 percent.
• Molybdenum may be added as asolid solution strengthener and as an additional carbide forming element. Amounts up to 10 percent molybdenum may be employed although, preferably, the molybdenum content does not exceed 3 percent.
• the composite products of the invention may be readily produced by techniques such as hot-rolling, codrawing and co-extrusion, including co-extrusion of a powder-metallurgically produced sintered cladding elei ment with a preformed foundation element to provide a metallurgical bond between the alloy elements forming the composite.
• co-extrusion can be conducted by disposing the body intended for the foundation within the body (e.g., a tube) intended for the cladding and carrying out the co-extrusion process at about 1,100 to 1,150C.
• a further benefit in the form of further reduced interdiffusion can be derived by interposing an interlayer consisting essentially of nickel between the foundation and cladding members.
• This interlayer acts as a sink for iron and chromium that might diffuse out of the cladding and foundation members, while diffusion of nickel from the interlayer into the cladding and foundation members is not found to be deleterious to the properties of the composite product.
• the interlayer is from to 40 pm thick, e.g., pm, but it may be greater if the composite article is to be exposed for long periods or to particularly high temperatures.
• the composite product may be produced by working an assembly of the foundation and cladding alloys with an intermediate layer of nickel.
• the nickel layer may be provided by known methods (e.g., plating) on the foundation element or on the cladding element before producing the composite product, or a nickel body (e.g., sheet) may be interposed between the foundation and the cladding elements before producing the composite product.
• the thickness of the nickel layer initially should be such that the desired thickness of nickel TABLE III Foundation alloy Cladding alloy composition composition (percent) (percent) Article number C Cr Mo Ti Al Mn Ni Fe Nb C Cr Zr Ni 0.07 16.5 3. 3 1. 2 1. 2 43. 5 Balance 0.018 40 0.85 Balance. 0.07 16.5 3.3 1.2 1 2 43.5 0.018 40 Do.
• Articles No. 1 and 2 of Table 111 are in accordance with the invention, while Articles A to D are outside 40 the invention and are included for reference purposes.
• the composite articles were sectioned and heated at 700C. for either 1,000 or 10,000 hours. After polishing, the carbide structures at the interfaces were electrolytically etched in either 10N potassium hydroxide solution or hydrogen fluoride solution or chemically etched in 2 percent nital. The samples were then examined optically and the diffusion distances of the major elements across the interface between the foundation and the cladding members, i.e., the depths of enrichment by said elements, were measured with an electron microprobe analyzer, the results being set forth in Table IV.
• the composite products of the invention are particularly suitable for use in heat-exchanger applications but may be employed in other applications demanding high strength and good corrosion resistance at elevated temperatures.
• a composite metal product comprising a foundation member and a cladding member metallurgically bonded together, said foundation member being made of an alloy consisting essentially of by weight, about 10 percent to about 45 percent nickel, about 15 percent to about 25 percent chromium, about 1 percent to about 4 percent of an element from the group consisting of titanium and niobium, up to about 4 percent aluminum, up to about 10 percent molybdenum, carbon up to about 0.1 percent, and the balance iron, and said cladding member being made of an alloy consisting essentially of about 45 percent to about 6 percent chromium, less than about 0.04 percent carbon, about 0.1 percent to about 4 percent zirconium, and the balance nickel.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Laminated Bodies (AREA)
• Pressure Welding/Diffusion-Bonding (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=26237883

Family Applications (1)

Country Status (9)

Cited By (6)

Families Citing this family (3)

Citations (6)

• 1971
  • 1971-01-22 GB GB295271A patent/GB1372232A/en not_active Expired
  • 1971-12-14 US US00208000A patent/US3718443A/en not_active Expired - Lifetime
  • 1971-12-31 CA CA131,522,A patent/CA950611A/en not_active Expired
• 1972
  • 1972-01-13 AT AT25172A patent/AT311691B/de not_active IP Right Cessation
  • 1972-01-20 IT IT47828/72A patent/IT948261B/it active
  • 1972-01-21 DE DE19722202794 patent/DE2202794A1/de active Pending
  • 1972-01-21 FR FR7202108A patent/FR2123014A5/fr not_active Expired
  • 1972-01-21 SE SE7200679A patent/SE372954B/xx unknown
  • 1972-01-21 BE BE778359A patent/BE778359A/xx unknown

Patent Citations (6)

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