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
• • 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
  • C22C19/056—Alloys based on nickel or cobalt based on nickel with chromium and Mo or W with the maximum Cr content being at least 10% but less than 20%

Definitions

• the present invention provides cast nickel alloys containing, in percent by weight, not more than about 0.05% or 0.06% carbon, e.g., about 0.03% carbon, about to about 18% chromium, about 5% to about 7% aluminum, up to about 1.5% titanium, e.g., 0.5% to about 1.5% titanium, about 1% to about 3% columbium, about 0.5% to about 6% molybdenum, with the chromium plus molybdenum contents being about to about 20% of the alloy, up to about 0.05%
• chromium advantageously is maintm'ned in the range of 10% to 14%.
• the total content of chromium and molybdenum in the alloy is import-ant and must be maintained in the range of 15% to 20% in order to provide the best combination that which exists in Thus, it is no longer It has accordinglybeen pro- .of corrosion resistance, strength, and ductility at elevated temperatures.
• Aluminum ⁇ is an important hardening and strengthening element in the alloy and is maintained in the range of 5% to ⁇ 7% because strength is ⁇ sacriticed if the concentration of this element is too low while the ductility is lowered if the concentration is above 7%.
• Titanium when present even in amounts of about 0.5%, contributes further hardening and strengthening to the alloy but should not exceed about 1.5% of the alloy because ductility and castability are reduced if the titanium content is higher than this value.
• Columbium also plays an important part in strengthening thealloy and is' employed in amounts of 1% to 3% because strength is sacrificed if Vthe concentration of this element is below 1%l while the ductility is reduced if the concentration is above'3r%; Boron and zirconium present in the alloy contribute-markedly to the development of satisfactory lem is crea-tedisince it is necessary to provide within a Y single unitary casting metallurgical structures'which will operate under vastly diiferent conditions of stress and temperature.
• the invention also contemplates providing gas turbinev are unsatisfactoryas OnV the other hand, it has been found' strength and ductility properties therein.
• the presence of fas little as 0.005% boron and at least about ⁇ ,0.02% zirconium provide good ductility- ⁇ at temperatures" ab'oveabout1000jo to 1200 F.
• Calcium in thealloy is employedin air melting to serve as a deoxidizer. It is omitted in vacuum melting..
• VIt is to be understood that ,carbon inthe ⁇ alloymust be Vmaintained at very low vales not exceeding 0.06% in order that the alloys will exhibit the required high elongation inthe as-cast condition at room temperature even in sections as heavy as three inches thick or more. Small carbon contents of about 0.03% arebeneiicial in producing the master alloy Vwhich is tobe remeltfed to make the finished castings.
• the alloy provided in accordance with the invention may also contain up toV 15% ⁇ cobalt, e.g., about V10% cobalt, assuch amounts of cobalt permit the inclusion in the alloy of as much as about 8% of aluminum without encounterling serious embrittling effects; vTungsten may be employed in ⁇ placebf apart or all of the molybdenum in the Aalloy.
• the alloy should be as devoid as practicable of impurities such as sulfur, phosphorus, lead, antimony, tin, selenium, tellurium, bismuth, etc. Elements such as silicon and 'manganese are undesirable and should not be present in amounts exceeding about 0.2% and 0.1%, respectively. 'Iron is also an undesirable element in the alloy ⁇ land should not be present in amounts exceeding about 0.5%, e.g., about 0.25%.
• the balance of the alloy is essentially nickel.
• the alloy provided in accordance with the invention is characterized by a room temperature'tensile strength -in the as-cast condition of at least about 100,000 p.s.i. and anelongation of at least about 10% in .the Ias-cast condition.
• the alloy provides relatively long service life at temperatures on the order of about 1700 ⁇ F. to
• The'following tables contain, respectively, the chemical :ompositions, in percent by Weight, of vacuum melted and vacuum cast alloys produced in accordance with the invention, the rupture lives of the alloys at 17.00 F. and 30,000 p.s.i. in the as-cast condition, and the room ternperature tensile properties of these alloys in the ⁇ as-cast j conditionz- Table I Alloy Perler- Per- Per- Per- Per- Per- Per- 'Per- Per- No. cent (eut cent cent ycent cent cent cent cent cent Cr Mo Cb A1 Ti C Zr Ni L v ,12 5 2 6 0.6 0.008 0.01 0.10 .Bal Z 12 5 2' 6 0.6 0.05 0.01 0.10 Bal.
• v f Y 1 A casting having atleast oneincluded section subjectedin use to high stressat temperatures on the order of Vabout 17009 F. and at least one included section subjected in use to high stress at temperatures on the order of about 1000* F., made of'anv alloy consisting' essentially of vabout0.008% ⁇ to 0.05%fcarbo'n, aboutv 12% chromium, about '5% molybdenum, Vabout 6% aluminum, .about 0.6% titanium, -about 2%, columbiurn, ⁇ about 0.01%
• i' f fAlloys in accorda ncewith the invention have particulalrly satisfactory properties when produced byr vacuum Y melting'. They may, however, be melted under argon or even under air'atmospheres with goodcastability and j. f
• the strength of the alloy at room temperature and atl i elevated temperatures may be improved by subjectingithe castings ,to a heat treatment comprising a heating at about j 215011?. for about 15 minutes to about'24'hours, e.g., about two hours, followed by acooling to roomtemperature. fjlffde'sired', a further stabilization treatment consisting of a heating at about 1700o F. for about one to about 24 hours, -ie.g.,about fourV hours, kmay also be employed. .in casting thefalloy, it is important to superheat the, melt 'topa temperature of, at least 300 F., butk more-advantageously at least about 400 F; or 500 F.,
• a pouring temperaturehvof about 2950 F. Y.
• a nickel-base al loy containing ⁇ not morey than about 0.06% carbon, about '10%.to 18% chromium, Vabout 0.5% to 6%V of a metal from the group consisting of molybdenum and tungsten andwith the total contents of chromium, molybdenum andtung'sten being about 15 to about 20%, about 5% to 8% aluminum, up to about 15% cobalt with the proviso that Wheri'theicobalt content isv lessthanvabout 10% ⁇ the aluminum content is about 5% to,7%, up to about 1.5% titanium, about 1% to 3% columbiurm about 0.01% boron,V up ,toV about 0.15%

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Turbine Rotor Nozzle Sealing (AREA)
• Moulds For Moulding Plastics Or The Like (AREA)

Priority Applications (11)

Applications Claiming Priority (1)

Publications (1)

Family

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Family Applications (1)

Country Status (11)

Cited By (13)

Citations (5)

• 1962
  • 1962-08-31 US US220857A patent/US3166412A/en not_active Expired - Lifetime
• 1963
  • 1963-08-21 GB GB33116/63A patent/GB968495A/en not_active Expired
  • 1963-08-28 ES ES291188A patent/ES291188A1/es not_active Expired
  • 1963-08-28 AT AT690963A patent/AT241133B/de active
  • 1963-08-29 FR FR946059A patent/FR1367387A/fr not_active Expired
  • 1963-08-29 CH CH1065763A patent/CH420635A/fr unknown
  • 1963-08-29 SE SE9421/63A patent/SE307018B/xx unknown
  • 1963-08-29 DE DEJ24337A patent/DE1219236B/de active Pending
  • 1963-08-30 NL NL297339D patent/NL297339A/nl unknown
  • 1963-08-30 BE BE636847D patent/BE636847A/fr unknown
  • 1963-08-31 LU LU44364D patent/LU44364A1/xx unknown

Patent Citations (5)

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