EP0808681A1 - Poudre de fer pour metallurgie des poudres, procede de production correspondant et melange de poudre a base de fer pour metallurgie des poudres - Google Patents
Poudre de fer pour metallurgie des poudres, procede de production correspondant et melange de poudre a base de fer pour metallurgie des poudres Download PDFInfo
- Publication number
- EP0808681A1 EP0808681A1 EP96935351A EP96935351A EP0808681A1 EP 0808681 A1 EP0808681 A1 EP 0808681A1 EP 96935351 A EP96935351 A EP 96935351A EP 96935351 A EP96935351 A EP 96935351A EP 0808681 A1 EP0808681 A1 EP 0808681A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- iron
- powder
- powders
- iron powders
- less
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
- C22C33/0264—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements the maximum content of each alloying element not exceeding 5%
Definitions
- the present invention relates to iron powders for powder metallurgy, a method of producing the iron powders, and iron base mixed powders for powder metallurgy, and more particular to powders which exhibit excellent machinability and abrasion resistance when the powders are sintered.
- the powder metallurgy is a technology as to the production of massive materials and shaped objects by pressing, binding, and sintering powdered metal.
- powdered metal copper powder and graphite powder are mixed with the iron powder and the mixture is molded and sintered to produce a sintered body having density of the order of 5.0 - 7.2 g/cm 3 usually.
- the utilization of such powder metallurgy makes it possible to produce an extremely complicated configuration of mechanical component with great accuracy in size. In a case where a mechanical component is to be produced with greater accuracy in size, it happens that a machine work, such as cutting, drilling or the like, is practiced on the sintered body.
- sulphur (S) or manganous sulfide (MnS) is mixed with iron powder in order to improve machinability of the sintered body.
- S sulphur
- MnS manganous sulfide
- those sulphur (S) and manganous sulfide (MnS) make it easy to perform cutting out of chips, or form a thin film of sulphur (S) or manganous sulfide (MnS) on a tool cutting face, so that the thus formed thin film exhibits a lubrication action.
- Japanese Patent Publication (Kokoku) Hei.3-25481 proposes iron powders for powder metallurgy which are produced by means of atomizing with water or gas a molten steel in which 0.03-0.07 weight % of S is added to pure iron containing 0.1-0.5 weight % of Mn, Si and C.
- machinability of the sintered body produced by the use of such iron powders is simply improved by about twice or less as compared with that produced by the use of the conventional iron powders. Thus, the more improvement has been required in this respect.
- Japanese Patent Application Laid Open Gazette (Kokai) Sho.61-253301 proposes alloy steel powders comprising: at least one type of components of not more than 0.10 wt% of C, not more than 2.0 wt% of Mn, not more than 0.30 wt% of O, 0.10-5.0 wt% of Cr, 0.10-5.0 wt% of Ni, not more than 2.0 wt% of Si, 0.10-10.0 wt% of Cu, 0.01-3.0 wt% of Mo, 0.01-3.0 wt% of W, 0.01-2.0 wt% of V, 0.005-0.50 wt% of Ti, 0.005-0.50 wt% of Zr, 0.005-0.50 wt% of Nb,0.03-1.0 wt% of P and 0.0005-1.0 wt% of B; if necessary, not more than 1.0 wt% of S; and the remains which are substantially Fe.
- the alloy steel powders are produced in such a manner that iron powders, which are formed through a rough reduction of iron oxide such as iron ore, mill oxide and the like, and mother alloy powders, which are formed through a water-atomizing of molten steels pre-alloyed with a lot of metallic elements, are mixed with one another and the thus mixed powders are subjected to a finish reduction process. Consequently, such alloy steel powders are produced in a very complicated scheme, and in addition contain a lot of alloy elements in large quantities. Thus, such alloy steel powders are expensive.
- the above-mentioned mother alloy powders formed through the water-atomizing comprises: at least one type of components of not more than 0.50 wt% of C, not more than 5.0 wt% of Mn, not more than 1.5 wt% of O, 0.10-20.0 wt% of Cr, 0.15-20.0 wt% of Ni, not more than 5.0 wt% of Si, 0.15-20.0 wt% of Cu, 0.015-15.0 wt% of Mo, 0.015-15.0 wt% of W, 0.015-5.0 wt% of V, 0.01-2.0 wt% of Ti, 0.01-2.0 wt% of Zr, 0.01-2.0 wt% of Nb, 0.04-2.0 wt% of P and 0.0010-2.0 wt% of B; if necessary, not more than 4 wt% of S; and the remains which are substantially Fe.
- an amount of residual graphite was about 0.42 wt% in the maximum, and composition of iron powders including above 0.03 wt% of B and above 0.1 wt% of Mn involved no improvement of machinability.
- iron powders capable of producing sintered steels containing a large amount of graphite in sintered bodies.
- an important feature of the present invention resides in the point that segregation of boron (B) not less than a predetermined amount on surfaces of the iron powders is induced.
- the present invention is to embody the above-mentioned knowledge. That is, according to the present invention, there is provided an iron powder for powder metallurgy characterized in that the iron powder comprises 0.03 - 0.3 wt% of B, not more than 0.07 wt% of Cr, less than 0.3 wt% of Mn, and a balance being Fe and inevitable impurities, and an intensity ratio of Fe and B as to an emission spectrum obtained through a measurement on a surface of the iron powder according to Auger electron spectroscopy is not less than 0.05.
- an iron powder for powder metallurgy characterized in that in addition to the above-mentioned compositions, said iron powder further comprises 0.001 - less than 0.20 wt% in total of one or more of S, Se and Te, or comprises 0.05 - 3.5 wt% of Mo.
- an iron base mixed powder for powder metallurgy characterized in that 0.05 - 0.7 wt% of MoO 3 powder and/or 0.05 - 0.7 wt% of WO 3 powder are mixed with the iron powder mentioned above.
- a method of producing iron powders for powder metallurgy characterized in that a molten steel, which comprises 0.03 - 0.3 wt% of B, not more than 0.07 wt% of Cr, less than 0.3 wt% of Mn, not more than 100ppm of oxygen, and a balance being Fe and inevitable impurities, is used, said molten steel is water-atomized into powders, and the powders are sequentially subjected to dehydration dry and reduction treatments.
- said molten steel further comprises 0.001 - less than 0.20 wt% in total of one or more of S, Se and Te, or comprises 0.05 - 3.5 wt% of Mo.
- iron powders for powder metallurgy capable of easily producing sintered bodies having excellent machinability and abrasion resistance as compared with prior art.
- Fig. 1 is a view showing, by way of example, emission spectrum obtained through measurement of surfaces of iron powders related to the present invention by Auger electron spectroscopy.
- Fig. 2 is a graph showing examples of concentration distributions of elements of interest at positions in depth direction from surfaces of iron powders measured by Auger electron spectroscopy.
- sputtering time of the abscissa axis is associated with a distance in depth direction from surfaces of iron powders.
- the present invention there is provided such a process that the content of Cr and Mn in iron powders is suppressed to be little, and to the contrary, the content of boron (B) is actively increased, so that segregation of boron (B) on surfaces of the iron powders may be induced.
- an amount of residual graphite contained in sintered bodies produced with the thus obtained iron powders is increased as compared with the conventional sintered bodies, thereby improving machinability.
- a first important feature of the present invention resides in the point that a molten steel, in which the content of oxygen is below 100ppm, is atomized.
- a second important feature of the present invention resides in the point that a degree of segregation of boron (B) on surface of iron powders is defined as claimed.
- the combination use of S, Se and Te with the above-mentioned boron (B) promotes the effects mentioned above.
- iron powders containing Mo it is more effective in improvement of machinability of sintered bodies that MoO 3 powders are mixed with the above-mentioned iron powders according to the present invention, rather than that Mo is added at stage of the molten steel through a process in which Mo is pre-alloyed. Since WO 3 powders also exhibit the similar effect to MoO 3 powders, such WO 3 powders are involved in the present invention.
- Part of B added to molten steels is deposited on surfaces of iron powders in the form of an oxide, when the molten steel is atomized. And when the green compact of the iron powders is sintered, the oxide serves to suppress a diffusion of carbon into iron particles, so that an amount of residual graphite in the sintered body is increased. As a result, it is possible to improve machinability and abrasion of the sintered body. Further, boron oxides are very stable in chemistry and does not react with H 2 .
- Containing B not less than 0.03 wt% causes an amount of residual graphite to be extremely increased, and as a result, it is possible to improve machinability and abrasion of the sintered body.
- 0.03 wt% of B is determined as the lower limit.
- part of B is solid-soluted on iron powder particles, so that hardness of the sintered body is increased thereby deteriorating the machinability.
- 0.3 wt% of B is determined as the upper limit.
- B on surfaces of iron powders above 0.05 in intensity ratio of B to Fe as to emission spectrum derived through a measurement by Auger electron spectroscopy
- Fig. 1 shows by way of example emission spectrum derived through the measurement.
- the intensity ratio of B to Fe implies the ratio of a peak-to-peak value of B corresponding to electronic energy 179eV (abscissa axis) to a peak-to-peak value of Fe corresponding to electronic energy 703eV.
- an amount of residual graphite in the sintered body is increased in case of not less than 0.05 in the intensity ratio of B to Fe, it is not so in case of less than 0.05.
- Fig. 2 examples of concentration distributions of elements of interest at positions in depth direction from surfaces of iron powders measured by Auger electron spectroscopy.
- sputtering time of the abscissa axis is associated with a distance in depth direction from surfaces of iron powders.
- concentration of B on surfaces of iron powders is 17 % by atomic weight %. It is considered that B exists in the form of B 2 O 3 since oxygen is also concentrated together with B on the surfaces thereof.
- accelerating voltage of the primary electron beam was 10kV, and beam current was 1.1 ⁇ A.
- reading of the measured data was performed by 1.00eV/step and 50m sec/step; integration was performed eleven times; and five points differentiation was practiced to generate differential spectrum.
- Cr is easy to form oxides and covers surfaces of iron powders, thereby hindering surface segregation of B. Thus, it is necessary to limit the content of Cr as little as possible. Further, Cr forms carbide, so that hardness of sintered bodies is increased, thereby degrading machinability. For these reasons, according to the present invention, it is determined that Cr is not more than 0.07 wt%. Taking into account machinability and abrasion of the sintered body, and a manufacturing cost as well, it is preferable that Cr is 0.02 - 0.06 wt%.
- Mn is an element which serves to reduce residual graphite. Further, when Mn in iron powder particles reacts with S, Se and Te, compounds are formed. Such compounds serve to reduce S, Se and Te which are effective to increase residual graphite in sintered bodies. Furthermore, Mn forms oxides and covers surfaces of iron powders, thereby hindering segregation of B on the surface of the iron powder. For these reasons, containing not less than 0.3 wt% of Mn causes reduction of residual graphite in sintered bodies. This involves deterioration of machinability. Taking into account the refining cost required for reduction of an amount of Mn in the regulation step of the molten steel component, and machinability of the sintered body, it is preferable that Mn is 0.07 - 0.15 wt%.
- S, Se and Te are contained in order to increase an amount of residual graphite in sintered bodies.
- the total amount of S, Se and Te is limited to 0.001 - less than 0.20 wt%.
- 0.20 wt% is determined as the upper limit.
- less than 0.001 wt% involves no effect of increasing an amount of residual graphite.
- the range of 0.001 - less than 0.20 wt% is determined.
- Mo is contained in order to increase strength of iron powders.
- less than 0.05 wt% of Mo involves no improvement of strength of iron powders.
- exceeding 3.5 wt% of Mo involves rapid deterioration in machinability of sintered bodies.
- the above-noted range is determined.
- the preferable range is 0.4 - 0.7 wt%.
- MoO 3 powders and/or WO 3 powders are mixed with the above-mentioned iron powders according to the present invention so as to be utilized to form new mixed powders for powder metallurgy.
- Objects of the mixture are to improve machinability of sintered bodies and increase strength thereof by solid-solution hardening.
- Less than 0.05 wt% of total amount of MoO 3 powders and/or WO 3 powders involves no effects as mentioned above.
- exceeding 0.7 wt% of total amount of MoO 3 powders and/or WO 3 powders causes bainite to produce in iron particles, so that strength of the sintered body is deteriorated.
- the total amount of MoO 3 powders and/or WO 3 powders is limited to the range of 0.05 - 0.7 wt%.
- Iron powders according to the present invention are formed by way of water-atomizing molten steels controlled in the above-mentioned composition range. At that time, an amount of Oxygen (O) in the molten steel is determined to be below 100ppm, and preferably to be below 70ppm. Exceeding 100ppm of an amount of Oxygen (O) in the molten steel brings about a slagging by change of boron (B) into B 2 O 3 . This causes an amount of boron (B) effective for iron powders to decrease.
- Oxygen (O) in the molten steel is determined to be below 100ppm, and preferably to be below 70ppm.
- Exceeding 100ppm of an amount of Oxygen (O) in the molten steel brings about a slagging by change of boron (B) into B 2 O 3 . This causes an amount of boron (B) effective for iron powders to decrease.
- Oxygen (O) in the molten steel is limited as little as possible; Boron is molten in the molten steel and thereafter atomized; and the thus processed B is segregated on surfaces of iron powders in the form of B and B 2 O 3 through oxidizing of B with water.
- the iron powders formed by the water-atomizing process are subjected to dry, dehydration and reduction treatments as usual, and then crushed and classified to form iron powders.
- Applicant produced nine types of iron powders each type comprising B: 0.02 - 0.10 wt%, Cr: 0.02 - 0.04 wt%, Mn: 0.06 - 0.07 wt%, and the remainder of Fe and unavoidable impurity.
- the above-mentioned nine types of iron powders comprise five types of iron powders according to the present invention, and four types of iron powders (hereinafter, referred to as comparative examples) for comparison with the embodiment.
- a method of producing those types of iron powders is as follows.
- a molten steel of temperature 1630°C given with a predetermined composition was water-atomized to form powders.
- the thus obtained powders were dried at 140°C for 60 minutes under a nitrogen atmosphere, and then subjected to a reduction treatment at 930°C for 20 minutes under a pure hydrogen atmosphere. And after cooling, the powders taken out from a reducing furnace were crushed and classified to form items Nos. 1-6 shown in Table 1.
- iron powders further containing S: 0.02 - 0.10 wt% in addition to the composition of the above-mentioned iron powders.
- S 0.02 - 0.10 wt%
- the molten steel before atomizing is one in which iron containing carbon is added and the content of oxygen is controlled to a range of 40 -200 ppm.
- emission spectrums were measured in accordance with Auger electron spectroscopy, and an intensity ratio of peak-to-peak (179eV) of B and peak-to-peak (703eV) of Fe was calculated.
- a measurement method and measurement conditions are the same as the above-mentioned ones.
- An amount of residual graphite in the obtained sintered body was evaluated as follows.
- the content of residue which is obtained by dissolving the sintered bodies in nitric acid and filtrating with glass filter was measured by infrared-absorbing method.
- machinability of the sintered body it was estimated in such a manner that those iron powders were used to additionally produce a columnar sintered body of an external diameter of 60mm ⁇ and a height of 10mm, and the thus obtained sintered body is adopted as a sample. Concretely, first, a drill made of high-speed steel having 2 mm ⁇ in diameter was rotated under the conditions of 10000 rpm and 0.012 mm/rev to form a lot of apertures on the sample.
- Applicant further produced many types of atomized iron powders each comprising compositions shown in Table 2.
- the above-mentioned types of iron powders comprise six types (Nos. 11, 12, 16, 18, 23 and 24) of iron powders according to the present invention, four types of iron base mixed powders (Nos. 13, 14, 15 and 17) and four types of comparative examples (Nos. 19 - 22).
- Table 2 shows also an amount of oxygen in molten steels before water-atomized.
- the sintered bodies produced with the atomized iron powders and the iron base powders according to the present invention include a large amount of residual graphite, elongate life-times of tools, and are excellent in machinability.
- Applicant produced several types of atomized iron powders each comprising compositions shown in Table 3.
- the above-mentioned types of iron powders comprise four types (Nos. 25 - 28) of iron powders according to the present invention and four types of comparative examples (Nos. 29 - 31).
- 2 wt% of graphite powders and 15 wt% of copper powders were mixed with those iron powders, and as lubricant 1 wt% of zinc stearate was added and thereafter green compacts were formed under pressure to 6.85 g/cm 3 of density. Next, these green compacts were sintered at 1130 °C for 20 minutes under an RX (endothermic gas) atmosphere.
- Table 3 shows also an amount of residual graphite in the obtained sintered bodies and a spectrum intensity ratio of B to Fe according to Auger electron spectroscopy mentioned above.
- the applicant produced a cylindrical test sample of inside diameter 10mm ⁇ x outside diameter 20mm ⁇ x height 8mm, and inserted a shaft made of S45C of diameter 10mm ⁇ into the cylinder with a clearance 20 ⁇ m as to the inside wall. And an abrasion resistance test was performed in such a way that the shaft was rotated at 100 m/min by circumferential speed under dry conditions and load was increased gradually from the light load. In other words, the load at the time when sticking has occurred between the shaft and the inside wall of the cylinder is selected as the abrasion resistance index.
- Items Nos. 25 - 28 of iron powders according to the present invention have an abrasion resistance not less than 4 kgf/cm 2 by load. As apparent from the above, when an amount of graphite in the sintered bodies is not less than 1 wt%, the abrasion resistance is extremely improved. On the other hand, item No. 29 of iron powders noted as the comparative example is few in segregation of B; item No. 30 of iron powders does not contain B; and item No. 31 of iron powders contain too much B. Thus, abrasion resistances of the sintered bodies produced with the use of those materials are inferior as compared with the iron powders according to the present invention. Table 3 No.
- Iron powders for powder metallurgy and iron base mixed powders according to the present invention are more excellent in machinability and abrasion resistance of sintered bodies as compared with the conventional iron powders and mixed powders, when those powders are sintered in the form of green compacts. Consequently, when those powders are used to produce mechanical parts in accordance with a method of powder metallurgy of concern, it is possible to increase a dimensional accuracy of the mechanical parts and elongate the life-time thereof. Thus, the present invention is very useful in an industry.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Powder Metallurgy (AREA)
- Manufacture Of Metal Powder And Suspensions Thereof (AREA)
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP270275/95 | 1995-10-18 | ||
| JP27027595 | 1995-10-18 | ||
| PCT/JP1996/003007 WO1997014523A1 (fr) | 1995-10-18 | 1996-10-17 | Poudre de fer pour metallurgie des poudres, procede de production correspondant et melange de poudre a base de fer pour metallurgie des poudres |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| EP0808681A1 true EP0808681A1 (fr) | 1997-11-26 |
| EP0808681A4 EP0808681A4 (fr) | 1999-12-29 |
Family
ID=17483989
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| EP96935351A Withdrawn EP0808681A4 (fr) | 1995-10-18 | 1996-10-17 | Poudre de fer pour metallurgie des poudres, procede de production correspondant et melange de poudre a base de fer pour metallurgie des poudres |
Country Status (3)
| Country | Link |
|---|---|
| EP (1) | EP0808681A4 (fr) |
| JP (1) | JP3353836B2 (fr) |
| WO (1) | WO1997014523A1 (fr) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2162390C1 (ru) * | 1999-12-09 | 2001-01-27 | Общество с ограниченной ответственностью фирма "Спецметаллы" | Железный порошок, полученный распылением металлов |
| WO2010107372A1 (fr) * | 2009-03-20 | 2010-09-23 | Höganäs Aktiebolag (Publ) | Alliage de poudre de fer et de vanadium |
| US20110164715A1 (en) * | 2009-12-09 | 2011-07-07 | Korea Atomic Energy Research Institute | System and method for detecting leakage of nuclear reactor coolant using laser induced emission spectrum |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3346089A1 (de) * | 1983-12-21 | 1985-07-18 | Dr. Weusthoff GmbH, 4000 Düsseldorf | Verfahren zum herstellen hochfester, duktiler koerper aus kohlenstoffreichen eisenbasislegierungen |
| JPS61253301A (ja) * | 1985-04-30 | 1986-11-11 | Daido Steel Co Ltd | 粉末冶金用合金鋼粉末及びその製造方法 |
| US4849164A (en) * | 1988-02-29 | 1989-07-18 | General Motors Corporation | Method of producing iron powder article |
| JPH03247743A (ja) * | 1990-02-26 | 1991-11-05 | Kawasaki Steel Corp | 耐食性、被削性および鏡面性に優れた焼結合金鋼およびその製造方法 |
| JPH07233402A (ja) * | 1993-12-28 | 1995-09-05 | Kawasaki Steel Corp | 切削性、耐摩耗性に優れたアトマイズ鋼粉およびその焼結鋼 |
| JPH0892708A (ja) * | 1994-07-28 | 1996-04-09 | Kawasaki Steel Corp | 粉末冶金用混合鉄粉および切削性に優れた焼結鋼の製造方法 |
-
1996
- 1996-10-17 JP JP51569097A patent/JP3353836B2/ja not_active Expired - Fee Related
- 1996-10-17 EP EP96935351A patent/EP0808681A4/fr not_active Withdrawn
- 1996-10-17 WO PCT/JP1996/003007 patent/WO1997014523A1/fr not_active Ceased
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2162390C1 (ru) * | 1999-12-09 | 2001-01-27 | Общество с ограниченной ответственностью фирма "Спецметаллы" | Железный порошок, полученный распылением металлов |
| WO2010107372A1 (fr) * | 2009-03-20 | 2010-09-23 | Höganäs Aktiebolag (Publ) | Alliage de poudre de fer et de vanadium |
| US9469890B2 (en) | 2009-03-20 | 2016-10-18 | Hoganas Ab (Publ) | Iron vanadium powder alloy |
| US20110164715A1 (en) * | 2009-12-09 | 2011-07-07 | Korea Atomic Energy Research Institute | System and method for detecting leakage of nuclear reactor coolant using laser induced emission spectrum |
| US8855259B2 (en) * | 2009-12-09 | 2014-10-07 | Korea Atomic Energy Research Institute | System and method for detecting leakage of nuclear reactor coolant using laser induced emission spectrum |
Also Published As
| Publication number | Publication date |
|---|---|
| EP0808681A4 (fr) | 1999-12-29 |
| JP3353836B2 (ja) | 2002-12-03 |
| WO1997014523A1 (fr) | 1997-04-24 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US5571305A (en) | Atomized steel powder excellent machinability and sintered steel manufactured therefrom | |
| US4266974A (en) | Alloy steel powder having excellent compressibility, moldability and heat-treatment property | |
| KR100249006B1 (ko) | 분말도금용 물분무철분및 그 제조방법 | |
| EP0861698B1 (fr) | Mélange de poudres métalliques à base de fer | |
| US4985309A (en) | Alloyed steel powder for powder metallurgy | |
| JP3449110B2 (ja) | 粉末冶金用鉄系混合粉末およびこれを用いた焼結体の製法 | |
| JPH068484B2 (ja) | 加工可能なホウ素含有ステンレス鋼合金から製造される物品及びその製造方法 | |
| EP0648852A1 (fr) | Article en acier martensitique préparé par pressage isostatique à chaud pour moules et parties de matrices ainsi que son procédé de fabrication | |
| KR100505933B1 (ko) | 소결경화법에의한저합금강제조용분말 | |
| US20120156084A1 (en) | Method of manufacturing sintered ferromolybdenum alloy from mixed powder of mill scale and molybdenum oxide powder by solid gas reaction | |
| JP3273789B2 (ja) | 粉末冶金用の鉄粉および混合粉ならびに鉄粉の製造方法 | |
| US4131450A (en) | Process for manufacturing cobalt-base reduced powder | |
| US4587096A (en) | Canless method for hot working gas atomized powders | |
| EP0808681A1 (fr) | Poudre de fer pour metallurgie des poudres, procede de production correspondant et melange de poudre a base de fer pour metallurgie des poudres | |
| US6296682B1 (en) | Iron-based powder blend for use in powder metallurgy | |
| JP3294980B2 (ja) | 切削性に優れた高強度焼結材料用合金鋼粉 | |
| JPH07233401A (ja) | 切削性および寸法精度に優れたアトマイズ鋼粉および焼結鋼 | |
| US5599377A (en) | Mixed iron powder for powder metallurgy | |
| JPH1150103A (ja) | 粉末冶金用鉄粉の製造方法 | |
| JPH1180803A (ja) | 粉末冶金用鉄基混合粉 | |
| JPWO1997014523A1 (ja) | 粉末冶金用鉄粉、その製造方法及び粉末冶金用鉄基混合粉 | |
| US4671930A (en) | High hardness and high toughness nitriding powder metallurgical high-speed steel | |
| JPH10280083A (ja) | 粉末冶金用鉄基混合粉 | |
| JPH09111303A (ja) | 切削性および耐摩耗性に優れた焼結体が得られる鉄粉および鉄基混合粉 | |
| JP3347773B2 (ja) | 粉末冶金用純鉄粉混合物 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
| 17P | Request for examination filed |
Effective date: 19970524 |
|
| AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): SE |
|
| A4 | Supplementary search report drawn up and despatched |
Effective date: 19991116 |
|
| AK | Designated contracting states |
Kind code of ref document: A4 Designated state(s): SE |
|
| STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
|
| 18D | Application deemed to be withdrawn |
Effective date: 20000210 |