US3899319A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Powder mixture for the production of alloy steel with a low content of oxide inclusions
Assignee: Hoganas AB
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Filing: 1974-10-29
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Granted: 1975-08-12
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Expires: 1994-10-29
Abstract
Abstract A powder mixture for manufacturing of alloy steel wherein the metal powder portion consists of a mixture of two powders, viz. a first atomized prealloyed steel powder and a second non atomized alloy powder comminuted from a solidified melt. The alloying elements are distributed in such a way that elements, the oxides of which are easily reducible preferably nickel, copper, molybdenum and/or cobalt substantially enter into the atomized prealloyed steel powder and the oxidation sensitive elements especially chromium and manganese enter into the finely communited powder.
Inventors
- 👤 Per Folke Lindskog
- 👤 Per Gunnar Arbstedt
- 👤 Erik Goran Wastenson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:34
CPC Classifications
C; C22; C22C; C22C33/00; C22C33/02; C22C33/0257; C22C33/0264; C22C33/0207
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
112 words
A POWDER MIXTURE FOR MANUFACTURING OF ALLOY STEEL ARTICLES HAVING SMALL AND FEW OXIDE INCLUSIONS, COMPRISING A METAL POWDER PORTION WHICH CONSISTS OF A MIXTURE OF TWO POWDERS, VIZ. AN ATOMIZED PREALLOYED STEEL POWDER AND A FINELY COMMINUTED POWDER CONTAINING ALLOYING ELEMENTS, WHEREIN ALLOYING ELEMENTS, THE OXIDES OF WHICH HAVE A FREE ENERGY OF FORMATION WITH AN ABSOLUTE VALUE LESS THAN 120 KEAL/MOLE O2 (502 KJ/MOLE O2) AT 1000*C SUBSTANTIALLY ARE CONTAINED IN THE ATOMIZED PREALLOYED POWDER WHILE ALL ALLOYING ELEMENTS, THE OXIDES OF WHICH HAVE A FREE ENERGY OF FORMATION WITH AN ABSOLUTE VALUE EXCEEDING 120 KCAL/MOLE O2 (502 KJ/MOLE O2) AT 1000*C, ARE COMPLETELY CONTAINED IN THE FINELY COMMINUTED POWDER.
Claim 2
Dependent Claim
112 words
A POWDER MIXTURE FOR MANUFACTURING OF ALLOY STEEL ARTICLES HAVING SMALL AND FEW OXIDE INCLUSIONS, COMPRISING A METAL POWDER PORTION WHICH CONSISTS OF A MIXTURE OF TWO POWDERS, VIZ. AN ATOMIZED PREALLOYED STEEL POWDER AND A FINELY COMMINUTED POWDER CONTAINING ALLOYING ELEMENTS, WHEREIN ALLOYING ELEMENTS, THE OXIDES OF WHICH HAVE A FREE ENERGY OF FORMATION WITH AN ABSOLUTE VALUE LESS THAN 120 KEAL/MOLE O2 (502 KJ/MOLE O2) AT 1000*C SUBSTANTIALLY ARE CONTAINED IN THE ATOMIZED PREALLOYED POWDER WHILE ALL ALLOYING ELEMENTS, THE OXIDES OF WHICH HAVE A FREE ENERGY OF FORMATION WITH AN ABSOLUTE VALUE EXCEEDING 120 KCAL/MOLE O2 (502 KJ/MOLE O2) AT 1000*C, ARE COMPLETELY CONTAINED IN THE FINELY COMMINUTED POWDER.
Claim 3
Dependent Claim
136 words
A powder mixture according to claim 1, consisting of 80 to 99% of an atomized prealloyed powder of iron and 0.2 to 10% of said alloying elements, the oxides of which have a free energy of formation with an absolute value of less than 120 kcal/mole O2 (502 kJ/mole O2) at 1000* C, and of a finely comminuted powder consisting of a total of at least 25% and preferably at least 50% of said alloying elements, the oxides of which have a free energy of formation with an absolute value exceeding 120 kcal/mole O2 (502 kJ/mole O2) at 1000* C, at most 10% carbon, the rest iron and/or other alloying elements, the oxides of which have a free energy of formation with the absolute value lower than 120 kcal/mole O2 (502 kJ/mole O2) at 1000* C.
Claim 4
Dependent Claim
31 words
A powder mixture according to claim 1, in which the alloying elements contained in the atomized prealloyed powder consist of one or more of the elements nickel, copper, molybdenum and cobalt.
Claim 5
Dependent Claim
27 words
A powder mixture according to claim 1, in which the alloying elements of the finely comminuted powder are one or both of the elements chromium and manganese.
Claim 6
Dependent Claim
67 words
A powder mixture according to claim 1, in which that the finely comminuted powder consists of a ferroalloy with a total of at least 25% and preferably at least 50% of said alloying elements, the oxides of which have a free energy of formation with an absolute value exceeding 120 kcal/mole O2 (502 kJ/mole O2) at 1000* C, at most 10% of carbon and the balance iron.
Claim 7
Dependent Claim
34 words
A powder mixture according to claim 1, in which the finely comminuted powder has an average particle size according to Fischer of at most 20 Mu m and preferably at most 5 Mu m.
Claim 8
Dependent Claim
43 words
A powder mixture according to claim 1, in which the particle size distribution of the atomized prealloyed powder is such that more than 90% and preferably more than 97% of the powder passes a sieve with the mesh opening of 175 Mu m.
Claim 9
Dependent Claim
34 words
A powder mixture according to claim 1, in which the mixture contains in addition to the metal powder portion graphite and/or a lubricant such as zinc stearate up to a maximum 1% of each.
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) | 1978-08-11 | 1979-02-10 | 1979-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-11 | 1983-02-10 | 1983-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-11 | 1987-02-10 | 1987-08-12 | $7700.00 | Window Closed / Lapsed |