Allegheny Ludlum Industries, Inc.

Allegheny Ludlum Steel Corporation

Intech P/m Stainless Steel, Inc.

Orville W Reen

Raymond L Southern

Donald J McMahon

Merlin L Osborn

David J Hanlin, Sr

A blend of pre-alloyed stainless steel powder for use in producing sintered stainless steel, said powder consisting essentially of, by weight, up to 0.05% carbon, 22% to 26% chromium, 10% to 24% nickel, 2.7% to 5% molybdenum, 0.1% to 1% boron, up to 2.0% manganese, up to 2.0% silicon, balance iron and residuals, together with manganese sulfide particles added thereto until they comprise up to 4%, by weight, of the overall blend, experimental results having shown that the blend offers significant improvements in the machinability of the resulting steel. The patent also claims a method for making sintered steel using the blend, as well as the sintered steel resulting from the process.

Sintered liquid phase stainless steel, and prealloyed powder for

A method for producing a low carbon ferrous powder melt stock with a sulfur content of less than 5 parts per million is disclosed comprising the steps of atomizing molten steel into a powder, exposing the powder to a temperature of at least 2100.degree. F. in a hydrogen containing atmosphere until the sulfur content has been reduced to the desired level, and cooling the desulfurized powder to ambient temperature in a non-oxidizing atmosphere. During heat treatment an interconnected porosity of at least 10% is maintained for the powder.

Desulfurization process for ferrous powder

An improved method for producing a low carbon, low nitrogen ferrochromium containing molybdenum. The method comprises the steps of blending particles of high carbon ferrochromium and particles of an oxygen and molybdenum bearing compound, heat treating the blend in a vacuum at temperatures of 1600.degree. F. or over, and pressures of 10 torr or below, and cooling the blend. The improvement of this invention comprises the use of a high carbon ferrochromium and an oxygen and molybdenum bearing compound as the original materials.

Method for producing molybdenum bearing ferrochromium

A method of making a metal core for alternating current applications by powder metallurgy is disclosed. Ferro-magnetic powder is pressed into a cross section of the core, with the thickness of the cross section approaching that below which the green density is no longer uniform throughout the volume of the part. Additional cross sections are pressed to meet the overall core thickness requirement when the sections are subsequently stacked. The sections are stacked in non contacting relationship and sintered. The sections are separated by an air gap or magnetic insulating medium.

Sintered ferromagnetic powder metal parts for alternating current

A phosphorus-iron powder is disclosed for use in the pressing and sintering of soft magnetic parts. This powder comprises a substantially phosphorous free iron powder blended with a sufficient quantity of ferrophosphorus powder having an average particle size of at least 10 micron and a phosphorus content of from 18 to 30%, to arrive at a phosphorus content for the mixture in a range of from about 0.40 to 1.25%. By pressing the blended mixture to a green density of at least 6.0 grams per cubic centimeter, and sintering the pressed mixture in a nonoxidizing atmosphere at a temperature of at least 1900.degree.F., the part linear shrinkage during sintering is less than 2%.

Phosphorus-iron powder and method of producing soft magnetic material

Gases are removed from particles, such as ferrochrome, by providing a container having an open top and a vertical wall having closely spaced opening therein so constructed that the particles will not plug or pass therethrough. Preferably a central vertical tubular member is provided in the container with similar holes. The particles are placed in the container between its wall and the vertical member and heated in a furnace to a temperature at which the gases will evolve. The gases may be removed by having the furnace under vacuum or by the atmosphere in the furnace.

Apparatus for removing gases from particles

A process for producing a phosphorus-bearing soft magnetic material. The process includes the steps of: blending iron powder and ferro-phosphorus powder into a mixture containing from 0.4 to 1.25% phosphorus; pressing said blended mixture into a compact; and sintering said compact in a non-oxidizing atmosphere. The iron and ferro-phosphorus powder respectively have no more than 0.02 and 0.2% calcium. The ferro-phosphorus powder has from 12 to 30% phosphorus.

Process for producing soft magnetic material

Atomized, prealloyed stainless steel powder having an apparent density of at least 2.0 g./cu.cm. The steel consists essentially of, by weight, up to 0.3% carbon, up to 2.0% manganese, up to 0.05% phosphorus, up to 0.04% sulfur, up to 2.0% silicon, 17.5 to 18.0% chromium, 10.0 to 14.0% nickel, 2.5 to 3.0% molybdenum, balance iron and residuals.

Stainless steel powder

A sintered stainless steel having an overall density of at least 95% of full density and a morphology comprised of regions of sintered austenitic stainless steel and regions of solidified liquid phase. Moreover, a sintered steel which is made by: pressing and sintering pre-alloyed powder consisting essentially of, by weight, up to 0.05% carbon, 22 to 26% chromium, 10 to 24% nickel, 2.7 to 5% molybdenum, 0.1 to 1% boron, up to 2.0% manganese, up to 2.0% silicon, balance iron and residuals.

Prealloyed stainless steel powder for liquid phase sintering

A sintered ferritic stainless steel having an overall density no greater than 80% of full density. The steel consists essentially of, by weight, 12 to 30% chromium, up to 8% molybdenum, up to 2% silicon, up to 1.5% manganese, up to 0.04% phosphorus, up to 0.04% sulfur, up to 0.15% carbon, balance iron.

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New Kensington, PA, United States of America

Orville W Reen