Patent US5503428A successfully refreshed from Google Patents.
US3909239A
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Method of controlling bulk density of ferrous powder
Assignee: Vodafone GmbH
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Filing: 1973-06-27
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Granted: 1975-09-30
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Expires: 1993-06-27
Abstract
Abstract The bulk density of ferrous powder made by atomizing molten steel is controlled by adding oxygen to the atomizing process and by reducing subsequently any resulting oxides to obtain a spongy surface layer of the particles, having thickness in dependence upon the added oxygen and reducing bulk density accordingly.
Inventors
- 👤 Gerhard Findeisen
- 👤 Norbert Dautzenberg
- 👤 Hartmut Gesell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:33
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/082; C; C22; C22C; C22C33/00; C22C33/02; C22C33/0235
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
170 words
IN A METHOD FOR ATOMIZING MOLTEN IRON OR STEEL BY MEANS OF PRESSURIZED WATER ATOMIZING A POURING STREAM OF THE LIQUIDOUS IRON OR STEEL TO OBTAIN A FERROUS POWDER WHICH IS SUBSEQUENTLY ANNEALED FOR REDUCING THE OXYGEN AND CARBON CONTENT AND WHICH IS TO BE USED FOR PRESS-FORMING OF PARTS BY PRESSING SUCH POWDER INTO A MOLD THE IMPROVEMENT COMPRISING, ADDING PURE OXYGEN OR OXYGEN ENRICHED AIR AT AN OXYGEN PRESSURE FROM 2 TO 6 ATMOSPHERES TO THE WATER TO ENRICH THE RELATIVE OXYGEN CONTENT IN THE WATER, SO THAT THE PARTIAL PRESSURE OF THE OXYGEN IS LARGER THAN NORMAL, AND USING THE OXYGEN-ENRICHED WATER FOR THE ATOMIZATION SO AS TO INCREASE THE OXIDATION LAYER ON THE POWDER PARTICLES AS PRODUCED BY THE ATOMIZATION BEYOND THE LAYER THICKNESS AS RESULTING FROM MERE USE OF WATER AS ATOMIZING AGENT, SO THAT THE SURFACE OF THE INDIVIDUAL POWDER PARTICLES ARE SPONGY AS RESULTING FROM REMOVAL OF THE OXYGEN DURING SUBSEQUENT ANNEALING TO OBTAIN A REDUCTION IN THE BULK DENSITY OF THE POWDER.
Claim 2
Dependent Claim
170 words
IN A METHOD FOR ATOMIZING MOLTEN IRON OR STEEL BY MEANS OF PRESSURIZED WATER ATOMIZING A POURING STREAM OF THE LIQUIDOUS IRON OR STEEL TO OBTAIN A FERROUS POWDER WHICH IS SUBSEQUENTLY ANNEALED FOR REDUCING THE OXYGEN AND CARBON CONTENT AND WHICH IS TO BE USED FOR PRESS-FORMING OF PARTS BY PRESSING SUCH POWDER INTO A MOLD THE IMPROVEMENT COMPRISING, ADDING PURE OXYGEN OR OXYGEN ENRICHED AIR AT AN OXYGEN PRESSURE FROM 2 TO 6 ATMOSPHERES TO THE WATER TO ENRICH THE RELATIVE OXYGEN CONTENT IN THE WATER, SO THAT THE PARTIAL PRESSURE OF THE OXYGEN IS LARGER THAN NORMAL, AND USING THE OXYGEN-ENRICHED WATER FOR THE ATOMIZATION SO AS TO INCREASE THE OXIDATION LAYER ON THE POWDER PARTICLES AS PRODUCED BY THE ATOMIZATION BEYOND THE LAYER THICKNESS AS RESULTING FROM MERE USE OF WATER AS ATOMIZING AGENT, SO THAT THE SURFACE OF THE INDIVIDUAL POWDER PARTICLES ARE SPONGY AS RESULTING FROM REMOVAL OF THE OXYGEN DURING SUBSEQUENT ANNEALING TO OBTAIN A REDUCTION IN THE BULK DENSITY OF THE POWDER.
Claim 3
Dependent Claim
20 words
Method as in claim 1, wherein the molten steel is atomized by water at a pressure of about 50 atmospheres.
Claim 4
Dependent Claim
167 words
In a method for atomizing molten iron or steel by means of pressurized water atomizing a pouring stream of the liquidous iron or steel to obtain a ferrous powder which is subsequently annealed for reducing the oxygen and carbon content and which is to be used for press-forming of parts by pressing such powder into a mold, the improvement comprising, adding about 0.1 to 20 % hydrogen peroxide to the water to enrich the relative oxygen content inthe water, the content being the higher, the lower a bulk density of the powder to be made is desired; and using the oxygen-enriched water for the atomization so as to increase the oxidation layer on the powder particles as produced by the atomization beyond the layer thickness as resulting from mere use of water as atomizing agent, so that the surface of the individual powder particles are spongy as resulting from removal of the oxygen during subsequent annealing to obtain a reduction in the bulk density of the powder.
Claim 5
Dependent Claim
167 words
In a method for atomizing molten iron or steel by means of pressurized water atomizing a pouring stream of the liquidous iron or steel to obtain a ferrous powder which is subsequently annealed for reducing the oxygen and carbon content and which is to be used for press-forming of parts by pressing such powder into a mold, the improvement comprising, adding about 0.1 to 20 % hydrogen peroxide to the water to enrich the relative oxygen content inthe water, the content being the higher, the lower a bulk density of the powder to be made is desired; and using the oxygen-enriched water for the atomization so as to increase the oxidation layer on the powder particles as produced by the atomization beyond the layer thickness as resulting from mere use of water as atomizing agent, so that the surface of the individual powder particles are spongy as resulting from removal of the oxygen during subsequent annealing to obtain a reduction in the bulk density of the powder.
Claim 6
Dependent Claim
21 words
In a method as in claim 3, wherein the amount of hydrogen peroxide added is about 0.2 % to 4 %.
Claim 7
Dependent Claim
146 words
In a method for atomizing molten iron or steel by means pressurized water atomizing a pouring stream of the liquidous iron or steel to obtain a ferrous powder which is subsequently annealed for reducing the oxygen and carbon content and which is to be used for pressforming of parts by pressing such powder into a mold, the improvement comprising, using water for atomization which is enriched with gasesous oxygen at a partial pressure in excess of the partial pressure of oxygen in regular water, so as to increase the oxidation layer on the powder particles as produced by the atomization beyond the layer thickness as resulting from mere use of water as atomizing agent, so that the surface of the individual powder particles are spongy as resulting from removeal of the oxygen during subsequent annealing to obtain a reduction in the bulk density of the powder.
Claim 8
Dependent Claim
146 words
In a method for atomizing molten iron or steel by means pressurized water atomizing a pouring stream of the liquidous iron or steel to obtain a ferrous powder which is subsequently annealed for reducing the oxygen and carbon content and which is to be used for pressforming of parts by pressing such powder into a mold, the improvement comprising, using water for atomization which is enriched with gasesous oxygen at a partial pressure in excess of the partial pressure of oxygen in regular water, so as to increase the oxidation layer on the powder particles as produced by the atomization beyond the layer thickness as resulting from mere use of water as atomizing agent, so that the surface of the individual powder particles are spongy as resulting from removeal of the oxygen during subsequent annealing to obtain a reduction in the bulk density of the powder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-29 | 1979-03-31 | 1979-09-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-29 | 1983-03-31 | 1983-09-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-29 | 1987-03-31 | 1987-09-30 | $7700.00 | Window Closed / Lapsed |