The present invention relates to a corrosion-resistant or oxidation-resistant coating for metallic components, in particular gas turbine components of superalloys based on nickel or cobalt. By adding rhenium, the life of protective coatings, in particular of the MCrAlY type, under corrosive or oxidising conditions can be increased. The protective coating according to the invention contains, in addition to certain selected components and impurities, the following components (in percent by weight): 1 - 20%, prefeably 4 - 10%, of rhenium, 22 - 50% of chromium, 0 - 15% of aluminium, the amount of chromium and aluminium together being at least 25% and not more than 53%, 0.3 - 2% of yttrium and 0 - 3% of silicon, the remainder mainly being at least one of the elements selected from iron, nickel and cobalt, preferably one of the elements selected from nickel and cobalt. Protective coatings qualified for certain applications can be considerably improved with regard to the life under corrosive conditions by adding even smaller amounts of rhenium.

Rhenium-containing protective coating with high corrosion and oxidation resistance

A protective coating resistant to corrosion at medium and high temperatures is applied on a nickel-based or cobalt-based superalloy component. The protective coating essentially consists of the following elements (in percent by weight): 25 to 40% nickel, 28 to 32% chromium, 7 to 9% aluminum, 1 to 2% silicon, 0.3 to 1% of at least one reactive element of the rare earths, at least 5% cobalt; and impurities, as well as selectively from 0 to 15% of at least one of the elements of the group consisting of rhenium, platinum, palladium, zirconium, manganese, tungsten, titanium, molybdenum, niobium, iron, hafnium, and tantalum. The total share of the elements of the group is from 0 to a maximum of 15% and a remainder of at least 5% cobalt. The component and the coating applied thereon have a ductile brittle transition temperature below 500° C.

High temperature-resistant corrosion protection coating for a component, in particular a gas turbine component

A protective coating for metal components formed of nickel or cobalt-based superalloys essentially consists of the following constituents (in percentages by weight): 1 to 20% rhenium, 22 to 50% chromium, 0 to 15% aluminum, the share of chromium and aluminum taken together being at least 25% and at most 53%, 0.3 to 2% in total of at least one reactive element from the group consisting of the rare earths, and 0 to 3% silicon, impurities, as well as the following elective components: 0 to 5% hafnium, 0 to 12% tungsten, 0 to 10% manganese, 0 to 15% tantalum, 0 to 5% titanium, 0 to 4% niobium, and 0 to 2% zirconium, the total share of the elective components being from 0 to a maximum of 15%, and a remainder primarily being at least one of the elements iron, nickel, and cobalt.

Highly corrosion and/or oxidation-resistant protective coating containing rhenium

Boroaluminasilicate glass and blended compositions thereof with aluminasilicate glass as seals in feedthroughs.

Glass-metal seals

A superalloy component includes a substrate article of a superalloy, and a strengthenable, adherent coating on the substrate. The coating is preferably a nickel-base superalloy that is strengthened by the formation of gamma and gamma-prime phases. The coating is stronger than conventional MCrAlX coatings, and, therefore, more resistant to thermal fatigue. One operable coating has a composition, in weight percent, of about 7.5 percent cobalt, about 9 percent chromium, about 6 percent aluminum, about 1 percent titanium, about 1.5 percent molybdenum, about 4 percent tantalum, about 3 percent tungsten, about 3 percent rhenium, about 0.5 percent hafnium, about 0.3 percent yttrium, about 0.5 percent columbium, about 0.05 percent carbon, about 0.015 percent boron, about 0.015 percent zirconium, and balance nickel.

Strengthened protective coatings for superalloys

OF THE DISCLOSURE A process and an alloy are proved for producing high strength material having good ductility to provide a high strength, corrosion resistant alloy including the steps of (1) preparing a body of material having a composition consisting essentially of by weight, about 13% to 18%chromium, about 13% to 18% molybdenum, less than 0.01%carbon, less than about 6% iron, less than about 1.25%cobalt, less than about 4% tungsten, less than 0.5%aluminum, less than 1% manganese, less than 0.5% silicon, and the balance nickel with usual transient metals and impurities in ordinary amounts, and (2) thereafter aging said body at a temperature in the range about 900° and 1100°F to effect an A2B ordering reaction in the composition, the engineering properties of these alloys are parti-cularly useful where a combination of high strength, ductility and corrosion resistance is essential, such as shafts in centrifuges, marine shafts, propulsion components and the like.

High yield strength Ni-Cr-Mo alloys and methods of producing the same

Oxydationsbestaendige nickel-legierung, verfahren zu ihrer herstellung und ihre verwendung

An improved system for detecting the location of a molten metal/slag interface during the casting of electroslag remelted hollows is provided. The system includes a gamma ray radiation source (30) and a scintillation counter (40). The source (30) and counter (40) reside outside the casting crucible (1) and are held in fixed spatial relationships with respect to one another and with respect to the mandrel (10). The radiation from the source (30) is directed through the crucible (1) and through the annular casting zone (9) defined between the sidewalls of the upwardly driven mandrel (10) and the crucible (1). The counter (40) provides an electrical signal responsive to the rate of radiation events detected thereby.

ESR Hollows molten metal/slag interface detection

A weldable oxidation resistant cobalt-base alloy is provided containing a small but effective addition of lanthanum preferably in the range of 0.001 to 0.018 percent by weight.

Oxidation resistant alloys

A method is provided for adding reactive metals to a molten metal bath by forming said reactive metal into an elongated member, suspending said member generally lengthwise vertically of a mold and pouring metal to be treated into said mold, to make said formed member an integral part of the molten metal as it rises in the mold and is cooled.

Howard Joseph Klein

Papers

High yield strength Ni-Cr-Mo alloys and methods of producing the same

Oxydationsbestaendige nickel-legierung, verfahren zu ihrer herstellung und ihre verwendung

ESR Hollows molten metal/slag interface detection

Oxidation resistant alloys

Methods of adding reactive metals to form a remelting electrode