Cold-worked superalloys having improved resistance to hydrogen embrittlement are disclosed. These new superalloys are nickel- or cobalt-chromium-molybdenum superalloys and possess improved resistance to hydrogen embrittlement rendering them useful in deep sour gas wells.

Superalloys having improved resistance to hydrogen embrittlement and methods of producing and using the same

A nickel-chromium-molybdenum alloy capable of being age hardened for improved strength while maintaining high corrosion resistance contains in weight percent 19.5 to 22 chromium, 1.5 to 17.5 molybdenum, up to 3 iron, up to 1.5 manganese, up to 0.5 aluminum, up to 0.02 carbon, up to 0.015 boron, up to 0.5 silicon, up to 1.5 tungsten and up to 0.5 of each of hafnium, tantalum and zirconium, with a balance of nickel and impurities. Certain alloying elements must be present in amounts according to an equation here disclosed.

Age-hardenable, corrosion resistant Ni—Cr—Mo alloys

A nickel-chromium-molybdenum-niobium alloy affords high resistance to aggressive corrosives, including chlorides which cause crevice corrosion and oxidizing acids which promote intergranular corrosion, the alloy also being readily weldable and possessing structural stability at very low as well as elevated temperatures. The alloy consists essentially of, (by weight), 19-23% Cr, 12-15% Mo, 2.25-4% W, 0.65-2% Nb, 2-8% Fe, balance Ni.

Corrosion resistant nickel-base alloy

For use in making components which are required to have a very high resistance to uniform corrosion and against pitting and crevice corrosion under very highly corrosive conditions encountered in up to date chemical process technology and environmental protection technology, for instance, in flue gas desulfurizing plants for concentrating sulfuric acid, and which are required to be manufactured satisfactorily by conventional hot and cold forming processes an alloy is employed which contains (in % by weight) 22.0 to 24.0 chromium, 15.0 to 16.5 molybdenum, up to 0.3% tungsten, up to 1.5% iron, up to 0.4% vanadium, 0.1 to 0.4% aluminum, 0.001 to 0.04% magnesium and 0.001 to 0.01 calcium, balance nickel and inevitable accompanying elements and impurities.

Corrosion resistant hot and cold forming parts of Ni-Cr-Mo alloy and method of making same

A single step heat treatment for Ni-Cr-Mo alloys containing from 12% to 19% chromium and from 18% to 23% molybdenum provides higher yield strength, high tensile strength and other mechanical properties comparable to those observed in similar alloys age-hardened according to current practices. This treatment is done over a total time of at least 4 hours and preferably less than 50 hours. However, the treatment works for only those alloys having alloying elements present in amounts according to an equation here disclosed.

Aging treatment for Ni-Cr-Mo alloys

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.

Frank G Hodge

Papers

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