Patent US3887402A successfully refreshed from Google Patents.
US3887402A
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US
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Method for producing high density steel powders
Assignee: Individual
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Filing: 1973-12-26
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Granted: 1975-06-03
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Expires: 1993-12-26
Abstract
Abstract A process for producing high density steel powders for Powder metallurgy is disclosed, wherein the molten stream of low carbon steel or low carbon alloy steel is atomized by high pressure water jet or inert gas jet to be powders, and after drying, the powders are heated in such inert gas as nitrogen or argon, whereby the reduction, decarburization and softening of the powders are simultaneously carried out.
Inventors
- 👤 Yoshikazu Kondo
- 👤 Mitsuo Ohhori
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:27
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/02; B22F9/06; B22F9/08; B22F9/082; B22F1/00; B22F1/14; B22F1/142
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
80 words
A METHOD FOR PRODUCING HIGH DENSITY STEEL POWDERS, SUITABLE FOR POWDER METALLURGY; CHARACTERIZED IN THE ATOMIZED STEEL POWDERS AND ATOMIZED ALLOY STEEL POWDERS, HAVING 0.02 TO 0.38 PERCENT BY WEIGHT OF CARBON AND 0.20 TO 0.50 PERCENT BY WEIGHT OF OXYGEN CONTAINED AND WHEREIN THE QUANTITATIVE RELATION OF CARBON TO OXYGEN CAN MEET THE EQUATION C% = K.O% (K=0.375), ARE HEATED AT 600* TO 1,250*C IN INERT GAS, WHEREBY REDUCTION AS WELL AS DECARBURIZATION AND SOFTENING ARE SIMULTANEOUSLY CARRIED OUT.
Claim 2
Independent Claim
80 words
A METHOD FOR PRODUCING HIGH DENSITY STEEL POWDERS, SUITABLE FOR POWDER METALLURGY; CHARACTERIZED IN THE ATOMIZED STEEL POWDERS AND ATOMIZED ALLOY STEEL POWDERS, HAVING 0.02 TO 0.38 PERCENT BY WEIGHT OF CARBON AND 0.20 TO 0.50 PERCENT BY WEIGHT OF OXYGEN CONTAINED AND WHEREIN THE QUANTITATIVE RELATION OF CARBON TO OXYGEN CAN MEET THE EQUATION C% = K.O% (K=0.375), ARE HEATED AT 600* TO 1,250*C IN INERT GAS, WHEREBY REDUCTION AS WELL AS DECARBURIZATION AND SOFTENING ARE SIMULTANEOUSLY CARRIED OUT.
Claim 3
Independent Claim
82 words
A method for producing high density steel powders, suitable for powder metallurgy; characterized in that atomized steel powders and atomized alloy steel powders, having 0.02 to 0.38 percent by weight of carbon and 0.20 to 0.50 percent by weight of oxygen contained, and wherein the quantitative relation of carbon to oxygen can meet the equation C% K.O% (K 0.375 to 0.75), are heated at 600* to 1,250*C in inert gas, whereby reduction as well as decarburization and softening are simultaneously carried out.
Claim 4
Independent Claim
82 words
A method for producing high density steel powders, suitable for powder metallurgy; characterized in that atomized steel powders and atomized alloy steel powders, having 0.02 to 0.38 percent by weight of carbon and 0.20 to 0.50 percent by weight of oxygen contained, and wherein the quantitative relation of carbon to oxygen can meet the equation C% K.O% (K 0.375 to 0.75), are heated at 600* to 1,250*C in inert gas, whereby reduction as well as decarburization and softening are simultaneously carried out.
Claim 5
Independent Claim
99 words
A method for producing high density steel powders, suitable for powder metallurgy; characterized in that atomized steel powders and atomized alloy steel powders, having 0.20 to 0.50 percent by weight of oxygen and less than 0.38 percent of carbon contained besides, having a lower percentage of carbon than the relation shown by the equation C% K.O% (K 0.375 to 0.75), are heated at 600* to 1,250*C in inert gas after fine powders of carbon are added and mixed by the quantity of carbon, insufficient for said equation, whereby reduction as well as decarburization and softening are simultaneously carried out.
Claim 6
Independent Claim
99 words
A method for producing high density steel powders, suitable for powder metallurgy; characterized in that atomized steel powders and atomized alloy steel powders, having 0.20 to 0.50 percent by weight of oxygen and less than 0.38 percent of carbon contained besides, having a lower percentage of carbon than the relation shown by the equation C% K.O% (K 0.375 to 0.75), are heated at 600* to 1,250*C in inert gas after fine powders of carbon are added and mixed by the quantity of carbon, insufficient for said equation, whereby reduction as well as decarburization and softening are simultaneously carried out.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein the atomized steel powders and atomized alloy steel powders contain 0.02 to 0.26 percent by weight of carbon and 0.20 to 0.35 percent by weight of oxygen.
Claim 8
Dependent Claim
33 words
The method of claim 2 wherein the atomized steel powders and atomized alloy steel powders contain 0.20 to 0.35 percent by weight of oxygen and less than 0.26 percent by weight of carbon.
Claim 9
Dependent Claim
26 words
The method of claim 1 wherein said alloy steel powders contain at least one alloying element of Cu, Ni, Mo, Co, Cr, Mn, W and V.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein the inert gas is nitrogen or argon gas.
Claim 11
Dependent Claim
18 words
The method of claim 1 wherein the dew point of said inert gas employed is lower than -30*C.
Claim 12
Dependent Claim
17 words
The method of claim 1 wherein the heating time in inert gas is more than 10 minutes.
Claim 13
Dependent Claim
19 words
The method of claim 1 wherein the powders are atomized in the presence of a nitrogen inert gas atmosphere.
Claim 14
Dependent Claim
26 words
The method of claim 2 wherein said alloy steel powders contain at least one alloying element of Cu, Ni, Mo, Co, Cr, Mn, W and V.
Claim 15
Dependent Claim
14 words
The method of claim 2 wherein the inert gas is nitrogen or argon gas.
Claim 16
Dependent Claim
18 words
The method of claim 2 wherein the dew point of said inert gas employed is lower than -30*C.
Claim 17
Dependent Claim
17 words
The method of claim 2 wherein the heating time in inert gas is more than 10 minutes.
References Cited (Backward Citations)
US3746584A
Cited
US3732092A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |