A nickel, chromium, iron alloy and method for use in producing weld deposits and weldments formed therefrom. The alloy comprises, in weight percent, about 28.5 to 31.0% chromium; about 0 to 16% iron, preferably 7.0 to 10.5% iron, less than about 1.0% manganese, preferably 0.05 to 0.35% manganese; about 2.1 to 4.0% niobium plus tantalum, preferably 2.1 to 3.5% niobium plus tantalum, and more preferably 2.2 to 2.8% niobium plus tantalum; 0 to 7.0% molybdenum, preferably 1.0 to 6.5%, and more preferably 3.0 to 5.0% molybdenum; less than 0.50% silicon, preferably 0.05 to 0.30% silicon; 0.01 to 0.35% titanium; 0 to 0.25% aluminum; less than 1.0% copper; less than 1.0% tungsten; less than 0.5% cobalt; less than about 0.10% zirconium; less than about 0.01% sulfur; less than 0.01% boron, preferably less than 0.0015% boron, and more preferably less than 0.001% boron; less than 0.03% carbon; less than about 0.02% phosphorous; 0.002 to 0.015% magnesium plus calcium; and balance nickel and incidental impurities. The method includes the steps of forming a welding electrode from the above alloy composition and melting the electrode to form a weld deposit. A preferred weldment made from the alloy and method includes an alloy substrate in the form of a tubesheet of a nuclear reactor.

Welding alloy and articles for use in welding, weldments and method for producing weldments

A heat resistant Ni base alloy comprises, on a mass% basis, 0.1% or less C, 2% or less Si, 2% or less Mn, 0.005% or less S, 10 to 25% Cr, 2.1 to less than 4.5% Al, 0.08% or less N, 0.001 to 1% in total of one or more elements of B: 0.03% or less, Zr: 0.2% or less and Hf: 0.8% or less, and 2.5 to 15% in total of one or more elements of Mo: 0.01 to 15% and W: 0.01 to 9%. The alloy is suitable as a material for a pipe used in ethylene cracking furnace.

Heat resistant nickel base alloy

A improved hydrocarbon conversion process, comprising applying a plating, cladding, paint or other coating to at least a portion of a hydrocarbon conversion reactor system which is used to convert hydrocarbons to products in the presence of steam, said coating being effective to reduce the amount of undesirable by-products in said process; and operating the hydrocarbon conversion process at a steam to hydrocarbon ratio that is lower than the steam to hydrocarbon ratio at which said process was operated prior to applying said coating. Preferred hydrocarbon conversion process includes steam cracking of hydrocarbons to produce ethylene and dehydrogenation of ethylbenzene to styrene.

Increasing production in hydrocarbon conversion processes

An electrode for an ignition device is made from a Ni-based nickel-chromium- iron alloy which has improved resistance to high temperature oxidation, sulfldation, corrosive wear, deformation and fracture includes, by weight of the alloy: 14.5-25% chromium; 7-22% iron; 0.2-0.5% manganese; 0.2-0.5% silicon; 0.1-2.5% aluminum; 0.05-0.15% titanium; 0.01-0.1% total of calcium and magnesium; 0.005-0.5% zirconium; 0.001-0.01% boron, and the balance substantially Ni. It may also include at least one rare earth element selected from the group consisting of: yttrium, hafnium, lanthanum, cerium and neodymium in amounts ranging from 0.01-0.15% by weight, and incidental impurities, including cobalt, niobium, molybdenum, copper, carbon, lead, phosphorus or sulfur. These total of these impurities will typically be controlled to limits of 0.1% cobalt, 0.05% niobium, 0.05% molybdenum, 0.01% copper, 0.01% carbon. 0.005% lead, 0.005% phosphorus and 0.005% sulfur. The ignition device may be a spark plug which includes a ceramic insulator, a conductive shell, a center electrode disposed in the ceramic insulator having a terminal end and a sparking end with a center electrode sparking surface, and a ground electrode operatively attached to said shell having a ground electrode sparking surface, the center electrode sparking surface and the ground electrode sparking surface defining a spark gap therebetween. At least one of the center electrode or the ground electrode includes the solution- strengthened Ni-based nickel-chromium-iron alloy. The Ni-based nickel-chromium- iron alloy electrodes of the invention may also include a core with thermal conductivity greater than that of the Ni-based nickel-chromium-iron alloy, such as copper or silver or their alloys.

Electrode for an Ignition Device

This invention provides a molten salt, solar central smooth tube receiver that is able to effectively absorb a peak solar flux of 1.42 MW/M 2 by constructing the receiver from low cycle fatigue 625 alloy. Although higher flux levels are attainable for a smooth tube receiver by reducing the tube diameter to increase the salt's heat transfer coefficient, the receiver's size is optimized at this flux level to minimize capital and performance costs. Analogously, material provides substantial performance and capital cost improvements for receivers constructed with internally enhanced film coefficient tubes. The receiver's cost is minimized by utilizing autogenously welded and drawn tubing with the weld located at the tube's neutral axis to provide minimal strain at the weld.

Molten nitrate salt solar central receiver of low cycle fatigue 625 alloy

Nickel-chromium alloys consisting essentially of from 30-75 nickel, 12-30% chromium, up to 10% molybdenum, up to 8% tungsten, up to 15% cobalt, up to 5% of niobium and/or tantalum, titanium plus aluminum up to 5%, and carbon nitrogen and silicon in correlated percentages to thereby improve low cycle and thermal fatigue strength, the balance being from 0 to 50% iron.

Nickel-chromium alloy of improved fatigue strength

A carburization-resistant alloy comprising in weight percent about 50 to about 55% nickel, about 16 to 22% chromium, about 3 to about 45% aluminum, up to about 5% cobalt, up to about 5% molybdenum, up to about 2% tungsten, about 003 to about 03% carbon, up to about 02% rare earth element, balance essentially iron The alloy is useful for structures, objects, parts etc which are exposed in use to carburizing atmospheres and which, periodically are subjected to oxidizing atmospheres For example the alloys are useful for pyrolysis tubes used in the petrochemical industry which must periodically be subjected to oxidizing atmospheres to burn-out carbon deposits and which, during pyrolysis are in contact with atmospheres having log Po₂ spanning at least the range of -17 to -26 and which exist at various temperatures

Carburization resistant alloy

The stress-rupture strength of a nickel-chromium-molybdenum-cobalt alloy is enhanced by reason of a special morphological microstructure which in terms of carbides present is characterized by a predominant amount of the M6C carbide.

Nickel-base alloy

A composite tube structure having an inner substrate alloy and an outer, corrosion resistant alloy suitable for use in fluid-bed coal combustion reactors to form a water wall around at least a portion of the periphery of the fluid bed zone. The outer, corrosion resistant alloy centers around a composition of 0.1% carbon, 0.2% silicon, 0.5% manganese, 22% chromium, 3.8% aluminum, 0.4% titanium, 0.05% nitrogen, 0.2% molybdenum, 32% nickel, balance iron.

Alloy for composite tubing in fluidized-bed coal combustor

An oxidation resistant nickel-chromium based alloy possessing good stress rupture characteristics at elevated temperature and, in addition to nickel and chromium, containing correlated percentages of aluminum, titanium, nitrogen, carbon, etc.

Curtis Steven Tassen

Papers

Nickel-chromium alloy of improved fatigue strength

Carburization resistant alloy

Nickel-base alloy

Alloy for composite tubing in fluidized-bed coal combustor

High nickel chromium alloy