WO1991019582A1 - Iron-based powder, component produced therefrom, and method of producing the component - Google Patents

Iron-based powder, component produced therefrom, and method of producing the component Download PDF

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Publication number
WO1991019582A1
WO1991019582A1 PCT/SE1991/000404 SE9100404W WO9119582A1 WO 1991019582 A1 WO1991019582 A1 WO 1991019582A1 SE 9100404 W SE9100404 W SE 9100404W WO 9119582 A1 WO9119582 A1 WO 9119582A1
Authority
WO
WIPO (PCT)
Prior art keywords
weight
powder
iron
sintering
component
Prior art date
Application number
PCT/SE1991/000404
Other languages
French (fr)
Inventor
Per Engdahl
Caroline Lindberg
Original Assignee
Höganäs Ab
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Höganäs Ab filed Critical Höganäs Ab
Priority to BR919106546A priority Critical patent/BR9106546A/en
Priority to DE69112214T priority patent/DE69112214T2/en
Priority to CA002084679A priority patent/CA2084679C/en
Priority to EP91911997A priority patent/EP0533812B1/en
Priority to JP51115991A priority patent/JP3280377B2/en
Publication of WO1991019582A1 publication Critical patent/WO1991019582A1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F1/00—Metallic powder; Treatment of metallic powder, e.g. to facilitate working or to improve properties
    • 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%
    • 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
    • C22C33/0207—Using a mixture of prealloyed powders or a master alloy
    • C22C33/0214—Using a mixture of prealloyed powders or a master alloy comprising P or a phosphorus compound

Definitions

  • the present invention relates to an iron-based powder for producing impact-resistant components by powder com ⁇ pacting and sintering.
  • the invention also concerns a powder-metallurgically produced component made from this powder. Finally, the invention bears upon a method of powder-metallurgically producing such a component.
  • iron-based powder-metallurgical materials are, to a certain extent, used in components requiring high impact energy. Natural ⁇ ly, this necessitates high precision when manufacturing the components, the effect of the porosity on impact energy being well-known.
  • the impact energy of sintered steel may be increased by alloying with Ni, which augments the strength and duc ⁇ tility of the material and, furthermore, causes shrinkage of the material, i.e. a density increase.
  • Ni-all ⁇ ying is especially pronounced when the sintering is carried out at a high temperature, i.e. above 1150°C.
  • the high temperature results in a more active sintering and produces rounder pores than do low sintering temperatures.
  • the rounder pores also increase the impact energy.
  • a more active sintering can be achieved by adding P, which increases strength and ductility, as well as rounds off the pores even at lower sintering temperatures, i.e. below 1150°C.
  • the impact energy of sintered materials can be increased by reducing the stress concentration effect of the pores. This can be achieved by liquid-phase sintering, high-temperature sintering, sintering of a ferritic material, double compacting, and by adding alloy ⁇ ing elements having a shrinking effect.
  • the object of the present invention is, therefore, to provide an iron-based powder which simplifies the process ⁇ ing, y ⁇ "t yields sufficiently impact-resistant components by powder compacting and sintering.
  • an iron-based powder which, in addition to Fe, contains Mo and P, and in which the content of other alloying elements is maintained on a low level.
  • This material is, inter alia, characterised by the fact that sintering even below 1150°C results in an impact energy which is higher than that of today's powder- metallurgical materials sintered at higher temperatures. Further, the material has excellent compressibility and is capable of considerable shrinkage, giving a sintered mate- rial of high density. For one and the same density, the material of the invention further has a substantially higher impact energy than today's powder-metallurgical materials.
  • the amount of Mo in the material should be 0.3-3.5% by weight, preferably 0.5-2.5% by weight, and the amount of P should be 0.3-0.7% by weight, preferably 0.35-0.65% by weight, most preferably 0.4-0.6% by weight. Further, the amount of other alloying elements should not exceed 2% by weight, preferably not 1% by weight, and most prefer ⁇ ably not 0.5% by weight. In addition, C may be present in a maximum amount of 0.1% by weight, preferably 0.07% by weight.
  • This powder can be produced by making a base powder of pure Fe, or Fe and Mo in solid solution. This can be produced either as a water-atomised powder or as a sponge powder. Suitably, the base powder is annealed in a reduc- ing atmosphere to lower the content of impurities. Then, the powder is mixed with P, or Mo and P, and is compacted into the desired shape, whereupon sintering is carried out a temperature which advantageously is below 1150°C.
  • Example A base powder of Fe containing 1.5% by weight of Mo was prepared by water-atomisation. Then, 0.5% by weight of P was added. Test pieces were produced by compacting
  • test pieces were sin ⁇ tered at 1120°C for 30 min. The resulting densities and impact energies are apparent from the upper curve in
  • a powder according to the invention containing 1.5% 5 by weight of Mo and varying amounts of P in the range of 0-0.8% by weight was produced.
  • Test pieces were made by compacting at 589 MPa and sintering at 1120°C.
  • the result ⁇ ing impact energy in J is apparent from Fig. 2.
  • a maximum value is achieved at 0.5% by weight of 10 P; good values are obtained in the range of 0.3-0.7% by weight of P; even better values are obtained in the range of 0.35-0.65% by weight of P; and the best values are obtained in the range of 0.4-0.6% by weight of P.
  • P is present in the form of a phosphor com ⁇ pound, preferably iron phosphide, e.g. Fe stampP.
  • the other alloying elements may be of a type not 35 affecting the impact energy adversely, and common in pow ⁇ der metallurgy.

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Powder Metallurgy (AREA)
  • Soft Magnetic Materials (AREA)
  • Superconductors And Manufacturing Methods Therefor (AREA)
  • Hard Magnetic Materials (AREA)

Abstract

An iron-based powder for producing impact-resistant components by powder compacting and sintering contains, in addition to Fe, 0.3-0.7 % by weight of P, 0.3-3.5 % by weight of Mo, and not more than 2 % by weight of other alloying elements. A method of powder-metallurgically producing impact-resistant steel components comprises using an iron-based powder which, in addition to Fe, contains 0.3-0.7 % by weight of P, preferably 0.35-0.65 % by weight of P, 0.3-3.5 % by weight of Mo, preferably 0.5-2.5 % by weight of Mo, and not more than 2 % by weight, preferably not more than 1 % by weight, of other alloying elements; compacting the powder into the desired shape; and sintering the compact.

Description

IRON-BASED POWDER, COMPONENT PRODUCED THEREFROM, AND METHOD OF PRODUCING THE COMPONENT
The present invention relates to an iron-based powder for producing impact-resistant components by powder com¬ pacting and sintering.
The invention also concerns a powder-metallurgically produced component made from this powder. Finally, the invention bears upon a method of powder-metallurgically producing such a component.
The remaining porosity of sintered powder-metallur¬ gical materials impairs the mechanical properties of the materials, as compared with completely dense materials. This is a result of the pores acting as stress concentra- tions, as well as reducing the effective volume under stress. Thus, strength, ductility, fatigue strength, macro-hardness etc. in iron-based powder-metallurgical materials decrease as the porosity increases. Impact energy is, however, the property the most adversely affected.
Despite their impaired impact energy, iron-based powder-metallurgical materials are, to a certain extent, used in components requiring high impact energy. Natural¬ ly, this necessitates high precision when manufacturing the components, the effect of the porosity on impact energy being well-known.
The impact energy of sintered steel may be increased by alloying with Ni, which augments the strength and duc¬ tility of the material and, furthermore, causes shrinkage of the material, i.e. a density increase. The effect of
Ni-allσying is especially pronounced when the sintering is carried out at a high temperature, i.e. above 1150°C. Naturally, the high temperature results in a more active sintering and produces rounder pores than do low sintering temperatures. In addition, the rounder pores also increase the impact energy. Alternatively, a more active sintering can be achieved by adding P, which increases strength and ductility, as well as rounds off the pores even at lower sintering temperatures, i.e. below 1150°C.
To sum up, the impact energy of sintered materials can be increased by reducing the stress concentration effect of the pores. This can be achieved by liquid-phase sintering, high-temperature sintering, sintering of a ferritic material, double compacting, and by adding alloy¬ ing elements having a shrinking effect.
In many cases, however, sufficient impact energy is only achieved with a combination of the above measures, which usually requires extensive and costly processing when using alloying systems known in the powder-metallur¬ gical techniques of today.
The object of the present invention is, therefore, to provide an iron-based powder which simplifies the process¬ ing, y©"t yields sufficiently impact-resistant components by powder compacting and sintering.
It is further desired that simple powder compacting as well as sintering can be carried out in a belt furnace, i.e. at temperatures below about 1150°C.
This object is achieved by an iron-based powder which, in addition to Fe, contains Mo and P, and in which the content of other alloying elements is maintained on a low level. This material is, inter alia, characterised by the fact that sintering even below 1150°C results in an impact energy which is higher than that of today's powder- metallurgical materials sintered at higher temperatures. Further, the material has excellent compressibility and is capable of considerable shrinkage, giving a sintered mate- rial of high density. For one and the same density, the material of the invention further has a substantially higher impact energy than today's powder-metallurgical materials.
The amount of Mo in the material should be 0.3-3.5% by weight, preferably 0.5-2.5% by weight, and the amount of P should be 0.3-0.7% by weight, preferably 0.35-0.65% by weight, most preferably 0.4-0.6% by weight. Further, the amount of other alloying elements should not exceed 2% by weight, preferably not 1% by weight, and most prefer¬ ably not 0.5% by weight. In addition, C may be present in a maximum amount of 0.1% by weight, preferably 0.07% by weight.
This powder can be produced by making a base powder of pure Fe, or Fe and Mo in solid solution. This can be produced either as a water-atomised powder or as a sponge powder. Suitably, the base powder is annealed in a reduc- ing atmosphere to lower the content of impurities. Then, the powder is mixed with P, or Mo and P, and is compacted into the desired shape, whereupon sintering is carried out a temperature which advantageously is below 1150°C. Example A base powder of Fe containing 1.5% by weight of Mo was prepared by water-atomisation. Then, 0.5% by weight of P was added. Test pieces were produced by compacting
2 at a pressure of 4-8 ton/cm . The test pieces were sin¬ tered at 1120°C for 30 min. The resulting densities and impact energies are apparent from the upper curve in
2
Fig. 1, where the compacting pressure in ton/cm is the parameter. For instance, an impact energy of 180 J and a
2 density of 7.46 g/cm were obtained at a compacting pres-
2 sure of 8 ton/cm- . A test piece produced in the manner described above, but without Mo, had a much lower impact energy, as is apparent from the lower curve in Fig. 1.
At high-temperature sintering, the material shrinks more, which leads to higher density and, consequently, to higher impact energy. This is illustrated by the point A on the"upper curve in Fig. 1, which was obtained at a co - pacting pressure of 6 ton/cm 2 and by sintering at 1250°C for 30 min.
It should be observed that the combined addition of P and Mo results in a higher sintered density than does a binary system of Fe and P, even if subjected to double compacting. For one and the same density, the material of the invention further gives a much higher impact energy, which in all probability should be attributed to a more active sintering and a positive interaction between Mo and P.
A powder according to the invention containing 1.5% 5 by weight of Mo and varying amounts of P in the range of 0-0.8% by weight was produced. Test pieces were made by compacting at 589 MPa and sintering at 1120°C. The result¬ ing impact energy in J is apparent from Fig. 2. As shown therein, a maximum value is achieved at 0.5% by weight of 10 P; good values are obtained in the range of 0.3-0.7% by weight of P; even better values are obtained in the range of 0.35-0.65% by weight of P; and the best values are obtained in the range of 0.4-0.6% by weight of P.
Similarly, a powder containing 0.5% by weight of • 15 P and varying amounts of Mo in the range of 0-4% by weight was produced. Test pieces were produced by compacting at 589 MPa and sintering at 1120°C. The resulting impact energy values are. apparent from Fig. 3. As shown therein, 0.3-3.5% by weight of Mo constitutes a useful range, 20 whereas 0.5-2.5% by weight of Mo constitutes a preferred range.
Very likely, the results obtained are due to the fol¬ lowing. The addition of P entails that a liquid phase is obtained during sintering at a comparatively low tempera- 25 ture, resulting in a better distribution of P in the mate¬ rial. P diffuses into the iron particles, and, to some extent, austenite is transformed to ferrite, which faci¬ litates the diffusion of Mo. Both P and Mo are ferrite stabilisers, and the transformation to ferrite increases 30 the self-diffusion of Fe. This gives an active sintering, resulting in shrinkage and round pores.
Suitably, P is present in the form of a phosphor com¬ pound, preferably iron phosphide, e.g. Fe„P.
The other alloying elements may be of a type not 35 affecting the impact energy adversely, and common in pow¬ der metallurgy. As non-restrictive examples, mention may be made of Ni, W, Mn and Cr. Cu should not be used at all.

Claims

1. An iron-based powder for producing impact-resis- tant components by powder compacting and sintering, c h a r a c t e r i s e d by containing, in addition to Fe, 0.3-0.7% by weight of P, 0.3-3.5% by weight of Mo, and not more than 2% by weight of other alloying ele¬ ments.
2. The powder of claim 1, c h a r a c t e r i s ¬ e d in that the amount of Mo is 0.5-2.5% by weight.
3. The powder of claim 1 or 2, c h a r a c t e r ¬ i s e d in that the amount of P is 0.35-0.65% by weight.
4. The powder of claim 1 or 2, c h a r a c t e r - i s e d in that the amount of P is 0.4-0.6% by weight.
5. The powder of any one of claims 1-4, c h a r ¬ a c t e r i s e d in that P is present in the form of iron phosphide, preferably Fe,P.
6. The powder of any one of claims 1-5, c h a r - a c t e r i s e d in that the amount of other alloying elements does not exceed 1% by weight, preferably not 0.5% by weight.
7. The powder of any one of claims 1-6, c h a r ¬ a c t e r i s e d by not containing more than 0.1% by weight of C, preferably not more than 0.07% by weight of C.
8. A powder-metallurgically produced component, c h a r a c t e r i s e d by containing, in addition to Fe, 0.3-0.7% by weight of P, 0.3-3.5% by weight of Mo, and not more than 2% by weight of other alloying elements.
9. A method of powder-metallurgically producing impact-resistant steel components, c h a r a c t e r ¬ i s e d by using an iron-based powder which, in addi- tion to Fe, contains 0.3-0.7% by weight of P, preferably 0.35-0.65% by weight of P, 0.3-3.5% by weight of Mo, pre¬ ferably 0.5-2.5% by weight of Mo, and not more than 2% by weight, preferably not more than 1% by weight, of other alloying elements; compacting the powder into the desired shape; and sintering the compact.
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PCT/SE1991/000404 1990-06-11 1991-06-07 Iron-based powder, component produced therefrom, and method of producing the component WO1991019582A1 (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
BR919106546A BR9106546A (en) 1990-06-11 1991-06-07 IRON BASE, COMPONENT PRODUCED FROM THE SAME, AND METHOD FOR PRODUCING THE COMPONENT
DE69112214T DE69112214T2 (en) 1990-06-11 1991-06-07 IRON BASE POWDER, MIXTURE THEREOF AND PRODUCTION OF THIS MIXTURE.
CA002084679A CA2084679C (en) 1990-06-11 1991-06-07 Iron-based powder, component produced therefrom, and method of producing the component
EP91911997A EP0533812B1 (en) 1990-06-11 1991-06-07 Iron-based powder, component produced therefrom, and method of producing the component
JP51115991A JP3280377B2 (en) 1990-06-11 1991-06-07 Iron-based powder, component manufactured therefrom, and method of manufacturing the component

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9002070A SE468583B (en) 1990-06-11 1990-06-11 YEAR-BASED POWDER, SHIPPING STEEL COMPONENTS OF THE POWDER AND WERE MADE TO MANUFACTURE THESE
SE9002070-2 1990-06-11

Publications (1)

Publication Number Publication Date
WO1991019582A1 true WO1991019582A1 (en) 1991-12-26

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Country Status (10)

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EP (1) EP0533812B1 (en)
JP (1) JP3280377B2 (en)
KR (1) KR100189234B1 (en)
AT (1) ATE126461T1 (en)
BR (1) BR9106546A (en)
CA (1) CA2084679C (en)
DE (1) DE69112214T2 (en)
ES (1) ES2075961T3 (en)
SE (1) SE468583B (en)
WO (1) WO1991019582A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4331938A1 (en) * 1993-09-16 1995-03-23 Mannesmann Ag Molybdenum-containing iron base powder
WO1995032827A1 (en) * 1994-05-27 1995-12-07 Höganäs Ab IRON BASED POWDER CONTAINING Mo, P AND C
WO2012089807A1 (en) * 2010-12-30 2012-07-05 Höganäs Ab (Publ) Iron based powders for powder injection molding

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP4616220B2 (en) * 2006-07-18 2011-01-19 Ｊｆｅテクノリサーチ株式会社 Method for producing hollow metal body
JP4641010B2 (en) * 2006-07-25 2011-03-02 Ｊｆｅテクノリサーチ株式会社 Hollow metal body

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2321103B2 (en) * 1972-05-02 1981-06-04 Höganäs AB, Höganäs Use of an iron-phosphorus alloy powder and process for the production of a phosphorus-containing steel powder
DE2613255C2 (en) * 1976-03-27 1982-07-29 Robert Bosch Gmbh, 7000 Stuttgart Use of an iron-molybdenum-nickel sintered alloy with the addition of phosphorus for the production of high-strength workpieces

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2321103B2 (en) * 1972-05-02 1981-06-04 Höganäs AB, Höganäs Use of an iron-phosphorus alloy powder and process for the production of a phosphorus-containing steel powder
DE2613255C2 (en) * 1976-03-27 1982-07-29 Robert Bosch Gmbh, 7000 Stuttgart Use of an iron-molybdenum-nickel sintered alloy with the addition of phosphorus for the production of high-strength workpieces

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
PATENT ABSTRACTS OF JAPAN, Vol. 9, No. 215, M409, Abstract of JP 60- 75501, publ. 1985-04-27 (KAWASAKI SEITETSU K.K.). *

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4331938A1 (en) * 1993-09-16 1995-03-23 Mannesmann Ag Molybdenum-containing iron base powder
WO1995032827A1 (en) * 1994-05-27 1995-12-07 Höganäs Ab IRON BASED POWDER CONTAINING Mo, P AND C
WO2012089807A1 (en) * 2010-12-30 2012-07-05 Höganäs Ab (Publ) Iron based powders for powder injection molding
CN103282527A (en) * 2010-12-30 2013-09-04 霍加纳斯股份有限公司 Iron based powders for powder injection molding
KR20140010026A (en) * 2010-12-30 2014-01-23 회가내스 아베 Iron based powders for powder injection molding
CN103282527B (en) * 2010-12-30 2016-03-23 霍加纳斯股份有限公司 For the iron-based powder of powder injection forming
US9314848B2 (en) 2010-12-30 2016-04-19 Hoganas Ab (Publ) Iron based powders for powder injection molding
RU2593064C2 (en) * 2010-12-30 2016-07-27 Хеганес Аб (Пабл) Iron-based powder for injection moulding of powder
KR20180061396A (en) * 2010-12-30 2018-06-07 회가내스 아베 (피유비엘) Iron based powders for powder injection molding
KR101867843B1 (en) * 2010-12-30 2018-06-18 회가내스 아베 (피유비엘) Iron based powders for powder injection molding
KR101912378B1 (en) * 2010-12-30 2018-10-26 회가내스 아베 (피유비엘) Iron based powders for powder injection molding

Also Published As

Publication number Publication date
KR930700243A (en) 1993-03-13
DE69112214D1 (en) 1995-09-21
JP3280377B2 (en) 2002-05-13
ATE126461T1 (en) 1995-09-15
SE9002070D0 (en) 1990-06-11
BR9106546A (en) 1993-06-01
JPH05507967A (en) 1993-11-11
ES2075961T3 (en) 1995-10-16
DE69112214T2 (en) 1996-01-04
CA2084679A1 (en) 1991-12-12
SE468583B (en) 1993-02-15
CA2084679C (en) 2003-04-01
EP0533812B1 (en) 1995-08-16
EP0533812A1 (en) 1993-03-31
KR100189234B1 (en) 1999-06-01
SE9002070L (en) 1991-12-12

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