CN101797641A - Sinter hardening raw material powder and sintered body thereof - Google Patents
Sinter hardening raw material powder and sintered body thereof Download PDFInfo
- Publication number
- CN101797641A CN101797641A CN200910143017A CN200910143017A CN101797641A CN 101797641 A CN101797641 A CN 101797641A CN 200910143017 A CN200910143017 A CN 200910143017A CN 200910143017 A CN200910143017 A CN 200910143017A CN 101797641 A CN101797641 A CN 101797641A
- Authority
- CN
- China
- Prior art keywords
- percentage
- powder
- weight
- sinter
- sintering
- 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.)
- Pending
Links
Images
Landscapes
- Powder Metallurgy (AREA)
Abstract
The invention relates to sinter hardening raw material powder and a sintered body thereof. The sinter hardening raw material powder can produce the sintered body with high strength, high hardness and high density. The raw material powder for sintering contains Fe serving as a main component thereof and also comprises 0.1 to 0.8 weight percent of C, 5.0 to 12.0 weight percent of Ni, 0.1 to 2.0 weight percent of Cr and 0.1 to 2.0 weight percent of Mo, wherein the average particle size of the raw material powder for sintering is equal to or less than 20 microns; and the sinter hardening powder uses iron powder or carbonyl iron powder or pre-alloying powder with low carbon and nickel content as base powder. A sintered and tempered blank has high hardness, high strength, high density and good ductility without any quenching treatment.
Description
Technical field
The present invention relates to a kind of sinter-hardened material powder, particularly relate to a kind of be used for by metal injection moulding (metal injection molding, MIM) technology or compacting sintering (press-and-sinter) technology make in sintered part(s), have high rigidity, high strength and highdensity characteristic.
Background technology
In order to obtain high rigidity and high strength, most of sintered part(s)s need heat treatment (for example quenching (quenching)) so that form martensite (martensite).Yet, when carry out quenching, may owing to when part from volumetric expansion or the thermal stress that owing to the quick cooling of Quenching Treatment cause of austenite (austenite) when being transformed into martensite take place for example to be out of shape, some problems such as size is inconsistent or break.In addition, part is carried out heat treatment and caused extra cost.Therefore, in compacting sintering technology, can add iron powder to by high hardenability (hardenability) alloying element with carbon and for example molybdenum, nickel, manganese and chromium, form sinter-hardening powder, extrude green compact (green compact) by conventional pressing process again, and will sintered part(s) be cooled to finished product with cooldown rate fast behind the green sintering subsequently with the hardness that is higher than HRC30.The example of the alloy that produces by the method is from the Ancorsteel737SH (Fe-0.42Mn-1.40Ni-1.25Mo-0.5C) of He Genasi (Hoeganaes) company and Ancorsteel 4300 (Fe-1Cr-1Ni-0.8Mo-0.6Si-0.1Mn-0.5C) powder and from the ATOMET 4701 (Fe-0.45Mn-0.90Ni-1.00Mo-0.45Cr-C) of Quebac Metal Porder Co., Ltd. (Quebec Metal Powders Limited).The assembly of being made by these powder need be in sintering furnace cools off for 30 ℃ with per minute at least, so that produce martensite.The 5th, 682, disclose another sinter-hardening powder in No. 588 United States Patent (USP)s, it relates to by the copper (Cu) of the Ni of 1 to 3 percentage by weight, 1 to 2 percentage by weight and powdered graphite are added to and having by the nickel (Ni) of 3 to 5 percentage by weights, the molybdenum (Mo) of 0.4 to 0.7 percentage by weight and the mixture of powders that all the other pre-alloyed powders of forming for iron (Fe) produce.The powder of being advocated is suppressed, sintering between 1130-1230 ℃, and cool off to obtain sinter-hardened effect with 5-20 ℃/minute speed subsequently.This can improve technology by the minimum cooldown rate that reduces by 30 described in the technology as mentioned previously ℃/minute.Yet, the intensity of these sinter-hardening powders and other character, especially ductility and toughness, still unsatisfactory.
(the Metal Powder Industries Federation of MPIF, MPIF) some material standards of the sinter-hardened alloy that is used for compacting sintering technology have also been stated, example is the FLNC-4408 (Ni of 1.0-3.0 percentage by weight, 0.65-0.95 the Mo of percentage by weight, 1.0-3.0 the Cu of percentage by weight, 0.05-0.3 the manganese of percentage by weight (Mn), 0.6-0.9 the carbon of percentage by weight (C), and remainder is iron (Fe)) and the FLC2-4808 (Ni of 1.2-1.6 percentage by weight, 1.1-1.4 the Mo of percentage by weight, 1.0-3.0 the Cu of percentage by weight, 0.3-0.5 the Mn of percentage by weight, 0.6-0.9 the C of percentage by weight, and remainder is Fe) prealloy type low-alloy steel powder.After sintering and tempering, sinter-hardened FLC2-4808 steel can reach 7.2g/cm
3The hardness of the hot strength of 1070MPa and HRC40 under the density, but ductility is less than 1.0%.Another standard of prealloy steel that can be sinter-hardened is FL-5305 (Fe-3Cr-0.5Mo-0.5C), and it can reach 7.3g/cm
3Density under the hot strength of 1100MPa and the hardness of HRC 33, but ductility is less than 1.0%.Although these compacting sintering alloys are sinter-hardened types, engineering properties is unsatisfactory, and required cooldown rate is still very fast, is at least 30 ℃/minute.Therefore, extra high cooldown rate system must be installed in sintering furnace.In addition, although required cooldown rate is slower than the quench rates of oil or water, these high cooldown rates still enough fast and cause for example distortion, size is inconsistent and problem such as hardening flaw.Therefore, still be starved of a kind of new sinter-hardened alloy, it can produce high rigidity, high strength, high density and good ductility, and allows the use than slow cool down speed.
(metal injection molding, MIM) technology is the manufacture method that produces the sintered part(s) with high density and complicated shape to metal injection moulding.In this technology, mix with having less than the mixed-powder of the average grain diameter of 30 μ m or pre-alloyed powder and binding agent.To be green compact through the material injection moulding that mixes, subsequently binding agent in the green compact be removed and sintering.Because the powder average grain diameter is little, diffusion length is shorter, therefore the alloying element that can homogenize and be added easily in matrix after sintering.Therefore, it is good to have the engineering properties of traditional compacting sintering part of powder of the average grain diameter between 50 μ m and the 100 μ m than common use from the part of attritive powder sintering.At present, the alloy that is generally used for metal injection moulding is the Fe-Ni-Mo-C alloy series, example be MIM-4605 (C of the Mo of the Ni of 1.5-2.5 percentage by weight, 0.2-0.5 percentage by weight, 0.4-0.6 percentage by weight,＜silicon (Si) of 1.0 percentage by weights, remainder is Fe), after sintering, this alloy reaches the hot strength of 440MPa, the hardness of HRB62 and 15% ductility.In order to obtain higher tensile strength and hardness, must quench to the product of sintering and tempering.It reaches the tensile strength of 1655MPa, the hardness of HRC48 and 2.0% ductility subsequently.It has the maximum intensity according to the MPIF standard.
Although the metal injection moulding product can obtain excellent engineering properties by the heat treatment after the sintering, heat treated cost and the defective products loss that brings owing to quenching have increased total cost of production.Therefore, need improve the competitiveness of sintered body by using sinter-hardening powder.Yet,, do not list sinter-hardened alloy for the metal injection moulding product according to MPIF's standard.And, up to the present the patent of Jie Shiing seldom be about can obtain with through quench and tempering after the similar sinter-hardening powder of intensity, hardness and density of base substrate.
Although there is not sinter-hardened MIM standard, the existing announcement at metal injection moulding technology is not some powdered steel of sinter-hardened grade.In particular, the 7th, 163, No. 569 United States Patent (USP) has disclosed a kind of atomizing pre-alloyed powder, and it can produce the product with even engineering properties and size.Form and comprise 0.8 percentage by weight or the following C of 0.8 percentage by weight, 0.05 Si to 1.0 percentage by weights, 1.0 the Mn that percentage by weight or 1.0 percentage by weights are following, 0.15, and further contain 2.0 percentage by weights or the following chromium (Cr) of 2.0 percentage by weights to the niobium (Nb) of 1.0 percentage by weights and the Ni of 1.0 to 10.0 percentage by weights, 3.0 the Mo that percentage by weight or 3.0 percentage by weights are following, 3.0 at least a element in the titanium (Ti) below Cu that percentage by weight or 3.0 percentage by weights are following and 0.05 percentage by weight or 0.05 percentage by weight.This pre-alloyed powder is to make by aerosolization or water atomization together with those pre-alloyed powders of appointment among FLNC-4408 and the FLC2-4808 usually, and uses when the distributing homogeneity of alloying element is crucial.A kind of widely used pre-alloyed powder is a stainless steel, and wherein the distribution of Ni and Cr must evenly make can obtain good anti-corrosion on all surface of part.Another example is tool steel (a for example D2 steel), and wherein the distribution of Cr, Mo, vanadium (V), Co and C must evenly make carbide can be dispersed in the matrix so that good wearability to be provided.Yet the production cost costliness of fine atomized powder is because only can use the sub-fraction of atomized powder like this.Another shortcoming is to lack flexibility when manufacturing has the alloy of specific composition.In order to make the part of composition with this type of client design, must send special order to the powder supplies merchant at this composition pre-alloyed powder of tool, it means the long stand-by period usually, has postponed the payment of final sintered products.By contrast, when using mixed-powder, can mix with base iron powder by for example oligo-element powder of Ni, Mo, Cr and make alloy with specific composition.Because the amount of the alloying element that adds is less, the inventory cost of therefore piling up these alloy powders is also lower.
In addition, although pre-alloyed powder provides homogeneous alloy, when using drawing method in making conventional compacting sintering product, this prealloy effect can cause bad compressibility and to the heavy wear of instrument.In MIM technology, because the higher hardness of pre-alloyed powder also can cause serious wearing and tearing to muller, injection moulding machine and mould.
In the alloy designs principle, also there is another difference between pre-alloyed powder and the mixed-powder, more needed elements may not need in mixed-powder when making pre-alloyed powder.For instance, when using atomization process, between melting stage, can add some Mn and Si usually, to reduce oxygen content and the melt flows between convenient atomization period in the molten iron.This also is that the most of alloys that why relate to fusing in the technology contain one of reason of Mn and/or Si.Yet being added in the mixture of powders of Mn and Si is unwanted, because Mn and Si oxidation during sintering easily, unless control to low-down level with dew point is careful.In addition, the addition of alloying element also is different, because mixture of powders is needed the alloying element of higher amount a little.Reason is can't obtain in practice to homogenize completely during sintering.There is different criterions in these example proofs when the alloy composition of design mixed-powder and pre-alloyed powder.
Owing to use these shortcomings of pre-alloyed powder, usually some other special alloy of only making stainless steel, tool steel and need complete homogeneous alloy with pre-alloyed powder.Most of MIM steel alloys are to make with the complex element powder, it comprise iron powder as basic powder and element powders or pre-alloyed powder as alloy powder.And, it is to make with high compressibility powder that great majority need the compacting sintering part of high green density, the present invention adopts element powders or softer ferroalloy powder as basic powder, for example Fe-Mo, Fe-Cr or Fe-Cr-Mo powder, it contains few carbon and nickel, because its compressibility of ferroalloy powder that carbon containing and nickel are many is poor, the content of general carbon and nickel is lower than 0.1 percent by weight.
Exist some to have and similar compacting sintering of composition of the present invention and MIM alloy at present.There is not unsuitable ductility loss in order to obtain improved hot strength, Marshall people such as (Marshall) discloses a kind of metal powder mixture in No. 1009425 BP, can make the sintered steel object by it, its composition comprises Ni, the Mn of 0.1 to 2 percentage by weight, the Mo of 0.1-5 percentage by weight, the C of 0.1-1 percentage by weight of 1-4.9 percentage by weight, and remaining is that iron adds common impurity.It further discloses, and nearly the iron of 5 percentage by weights can be by one or more other element replacements, and described element can influence the hot strength and the ductility of sintered part(s) sharply.The kind of described element and the upper limit comprise the aluminium (Al) of 1 percentage by weight, 0.3 the boron of percentage by weight (B), the Cr of 5 percentage by weights, the Cu of 5 percentage by weights, the magnesium of 1 percentage by weight (Mg), the Nb of 4 percentage by weights and/or Ta, 0.3 the phosphorus of percentage by weight (P), the Si of 1 percentage by weight, the Ti of 2 percentage by weights, the tungsten of 4 percentage by weights (W), 0.3 the V of percentage by weight, 0.6 the Zr of percentage by weight, 0.6 the Pb of the Se of percentage by weight and 0.5 percentage by weight.In order to obtain the complete advantage of this composition, No. 1009425 BP also stated and should use mixed-powder to replace pre-alloyed powder because can obtain showing, better engineering properties.The basis powder is the crude iron powder with particle mean size of about 50 μ m.In order to make sintered components, with mixed-powder compacting, removal binding agent and sintering between 1200 ℃-1400 ℃.Yet optimum stretch intensity is 1200Mpa only, is get by using the Fe-4.9Ni-0.5Mn-1Mo-0.6C alloy.
Described in the 7th, 163, No. 569 United States Patent (USP)s with the present invention in another alloy like the powdery type that discloses, it proposes a kind of pre-alloyed powder that is used for sintering owing to use pre-alloyed powder, it can produce has the accurate dimension and the even sintering MIM part of character.Particle mean size is below 8 microns or 8 microns.Yet pre-alloyed powder has aforesaid many shortcomings, for example low compacting green density, low frit density, low-intensity and soft.Table 1 show to use mixed-powder and pre-alloyed powder to reach hardness when not tempered in the density of 1190 ℃ and 1320 ℃ of following Fe-2Ni-0.3C and Fe-8Ni-0.8Cr-0.8Mo-0.5C base substrate.At Fe-8Ni-0.8Cr-0.8Mo-0.5C, in first group of sample, use to have the mixed-powder of carbonyl iron powder as basic powder.The Mo that is added in this mixed-powder is that the mode with element powders adds, the Cr that is added is that the form with the Fe-Cr-Ni pre-alloyed powder is added into Cr, and a Ni part is to add with the form of Fe-Cr-Ni pre-alloyed powder, and remaining insufficient section is that the mode with element powders adds.This routine sample does not add graphite, because carbonyl iron powder contains carbon.Second group of sample uses pre-alloyed powder.When the result is illustrated in the following sintering of 1190 ℃ and 1320 ℃ by using mixed-powder to obtain higher sintered density and higher hardness.In particular, under 1190 ℃ low temperature with the carbonyl iron powder mixture sintering to 7.52g/cm
3, and pre-alloyed powder 7.20g/cm only
3At Fe-2Ni-0.3C, in first group of sample, use to have the mixed-powder of carbonyl iron powder as basic powder.The Ni that is added in this mixed-powder is that the mode with element powders adds, and this routine sample does not add graphite yet, because carbonyl iron powder contains carbon.Second group of sample uses pre-alloyed powder.When the result is illustrated in the following sintering of 1190 ℃ and 1320 ℃ by using mixed-powder to obtain higher sintered density and higher hardness.In particular, under 1190 ℃ low temperature with the carbonyl iron powder mixture sintering to 7.50g/cm
3, and pre-alloyed powder 7.22g/cm only
3The bad sinterability of this examples show pre-alloyed powder.In order to obtain high sintered density, pre-alloyed powder is sintering at high temperature, yet because high temperature sintering must expend high-energy and high temperature sintering furnace costliness, so the total cost of production height.This has become main shortcoming, especially in today that the energy lacks.In addition, high temperature sintering can cause thicker crystal grain, the infringement engineering properties.Table 1 is also showed with mixed-powder than obtaining higher hardness with pre-alloyed powder.The sintered body of this mixed-powder have very uniformly micro-structural and crystal grain thin because used fine carbonyl iron powder.
Above background technology is emphasized under sintering temperature and low sintering and is had high rigidity and highdensity MIM base substrate needs the basic powder of careful selection, powder size, the good design combination of the type (that is, element powders or ferroalloy powder) of the powder used as alloy and high hardenability alloying element kind etc.Even being familiar with the technology of real sintering of compacting and metal injection moulding technology and the people of practice also is not easy design or selects this combination.This be why exist few its hardness of sinter-hardened alloy and intensity can with the present invention in the hardness that the obtains reason suitable with intensity.The character that obtains among the present invention Quenching Treatment behind the sintering.Only need be in tempering after the sintering.
Table 1 shows to have pre-alloyed powder and use the comparison of carbonyl iron powder as the Fe-Ni alloy of the mixed-powder of basic powder.
Table 1
| Form | Temperature | Character | Mixed powder | Prealloy powder |
| ??Fe-8Ni-0.8Mo-0.8Cr-0.5C | ??1190℃ | Density | ??7.52g/cm 3 | ??7.20g/cm 3 |
| Hardness | ??52HRC | ??28HRC | ||
| ??1320℃ | Density | ??7.59g/cm 3 | ??7.35g/c?m 3 | |
| Hardness | ??54HRC | ??49HRC | ||
| ??Fe-2Ni-0.3C | ??1190℃ | Density | ??7.50g/cm 3 | ??7.22g/cm 3 |
| Hardness | ??69HRB | ??63HRB | ||
| ??1320℃ | Density | ??7.56g/cm 3 | ??7.32g/cm 3 | |
| Hardness | ??79HRB | ??74HRB |
Mention as mentioned, the application enhancements of attritive powder the uniformity of alloying element and the engineering properties of product.Yet because the bad flowability of powder, the application of attritive powder is difficult in traditional compacting sintering technology, and it makes again and be difficult to powder is filled in the mold cavity, and therefore can't use the automation press forming.Yet, by attritive powder grain granulation (granulation) is become big spherolite, for example, can overcome these problems by spray-drying (spray drying) technology, this prilling powder promptly can be applicable in the compacting sintering technology.
In view of the aforementioned technical background, the invention provides a kind of raw material powder mixture or prilling powder, by described raw material powder mixture or prilling powder, can need not to quench after sintering to obtain to have the sintered body of high rigidity, high strength and high sintered density immediately.
Summary of the invention
Because the combination of the careful selection of basic powder and the careful selection of alloying element type and optimal amount the invention solves problem mentioned above.Mixture of powders of the present invention or granulated pellet sprills use elemental iron powder (for example, atomizing, reduction or carbonyl iron powder) as basic powder.Particle mean size is 20 μ m or below the 20 μ m.Alloying element comprises C, the Ni of 5.0-12.0 percentage by weight, the Cr of 0.1-2.0 percentage by weight, the Mo of 0.1-2.0 percentage by weight of 0.1-0.8 percentage by weight.More than form at least a other less important intensified element that can further contain the amount below 5.0 percentage by weights or 5.0 percentage by weights.The group that the optional free Cu of intensified element, Mn, Si, Ti, Al and P form.Can be by adding graphite or carbon black or using the carbonyl iron powder of carbon containing that carbon is provided.Described mixed-powder is suitable for the manufacturing of MIM sintered body.Described granulated pellet sprills are suitable for the manufacturing of compacting sintering base substrate.In addition, the present invention provides sintered body by using mixture of powders or granulated pellet sprills.Can need not quick cooling with the sinter-hardened described base substrate of the cold but speed of 3-30 ℃/minute normal stove in sintering furnace, other general sinter-hardening powder but needs described quick cooling.Sintered body of the present invention is without any need for Quenching Treatment.Only need lonneal promptly can obtain optimum engineering properties.Have by the made sintering main body of sinter-hardening powder mentioned above and have beyond example hardness, hot strength and good ductility.Because do not need quenching technical, so manufacturing cost is lower.And because the elimination of the defective of for example crackle that takes place during quenching and distortion, the present invention can obtain higher production yield.
For example consider above and to realize that at the general issues of compacting sintering and metal injection moulding product description the present invention can address these problems.The invention provides the sinter-hardening powder of original powder type (raw powder) or the sinter-hardening powder of granulation powder type (granulted powder) and be used for sintering, the base substrate behind the sintering can be realized high strength, high rigidity and high density simultaneously and need not any Quenching Treatment under the situation of slow cool down speed cooling.
In particular, the present invention relates to a kind of mixture of powders and granulated pellet sprills, it uses tiny iron powder end as basic powder (for example, atomizing, reduction or carbonyl iron powder), and its particle mean size is 20 μ m or below the 20 μ m.Alloying element comprises C, the Ni of 5.0 to 12.0 percentage by weights, the Cr of 0.1 to 2.0 percentage by weight and the Mo of 0.1 to 2.0 percentage by weight of 0.1 to 0.8 percentage by weight.Described powder can further contain at least a element among the following P of following Si of the following Cu1 percentage by weight of 2 percentage by weights or 2 percentage by weights or 1 percentage by weight following Ti, 1 percentage by weight or 1 percentage by weight following Al, 1 percentage by weight or 1 percentage by weight following Mn, 1 percentage by weight or 1 percentage by weight and 1 percentage by weight or 1 percentage by weight, and wherein nearly the iron content of 5 percentage by weights can be by the one or more replacements in these elements.But the base substrate sintering made from this powder and carry out the stove cooling with slow cool down speed subsequently, and still obtain hardness greater than HRC30.
Should be appreciated that the above-mentioned general description and the following specific embodiment only are exemplary and indicative, and do not limit the present invention who is advocated.
Description of drawings
Fig. 1 illustrates when Cr content increases, and by using metal injection moulding technology and use the hardness of the sintered body that fine carbonyl iron powder makes at first to increase, reaches maximum when about 0.7 percentage by weight, and reduces subsequently.
Fig. 2 illustrates when Cr content increases, and by using compacting sintering technology and use the hardness of the sintered body that the crude iron powder makes at first to increase, reaches maximum when about 3 percentage by weights, and reduces subsequently.
The specific embodiment
Reach technological means and the effect that predetermined goal of the invention is taked for further setting forth the present invention, below in conjunction with accompanying drawing and preferred embodiment, to sinter-hardening powder and its specific embodiment of sintered body, structure, feature and the effect thereof that foundation the present invention proposes, describe in detail as after.
To have high strength, high rigidity and highdensity sinter-hardened base substrate in order making economically, must to satisfy the some criterions that are used for material powder simultaneously.These criterions comprise: (a) contain the element with high hardenability, (b) with the attritive powder be basic powder, the feasible good homogenieity that can after sintering, obtain high density and alloying element, and the element that (c) contains optimal amount and ratio, make the high sinterability of tool, and used sintering temperature and low can obtain high density.In order to satisfy these requirements simultaneously, the characteristic and the alloy composition of necessary careful design sinter-hardening powder.
Carbon, manganese, silicon, chromium, molybdenum and nickel are castings or forge most popular element in (wrought) steel alloy.Yet, be not that all these elements all are suitable for MIM and compacting sintering part, unless take some preventive measures.For instance, residual oxygen in chromium quite reactive and easy and the sintering atmosphere or steam reaction and formation chromium oxide.Manganese is even has more reactive element, and easy and sintering atmosphere are reacted and the formation manganese oxide.Therefore and manganese and chromium have very high steam pressure, and when sintering pressed compact in a vacuum, the manganese that keeps in the sintered part(s) and the amount of chromium can show usually and reduce, unless argon gas is backfilling into certain level during sintering in a vacuum.Silicon is another high response element, and during sintering comparable Cr and the easier formation oxide of Mn.Although there are these problems, these alloying elements still can provide good induration, and condition is the form with ferroalloy powder, reducing its activity, and use the good sintering atmosphere (for example, having low dew point) of control, make to prevent that oxide from forming.One of method of using among the present invention is to add ferroalloy powder (for example Fe-Cr, Fe-Mn, Fe-Si) and derivative (for example, Fe-Cr-Mo, Fe-Cr-Mn etc.) thereof in base iron powder.These highly active Cr, Si and Mn alloying element alloying in powder and is used the pure element powder to compare its activity significantly to reduce.Therefore, these active elements can be in the normal sintering stove solid solution and can not form oxide in ferrous substrate, and provide required hardenability.In addition, sintering atmosphere should have high reducing power, for example has high hydrogen content and low water vapour content.When using vacuum drying oven, the necessary enough height of level of vacuum are in case the formation of oxidation thing.Simultaneously, should add the inert gas of some backfills, have the loss of the element (for example Cr and Mn) of high steam pressure with minimizing.
The sinter-hardening powder that discloses among the present invention comprises C, the Ni of 5.0-12.0 percentage by weight, the Cr of 0.1-2.0 percentage by weight, the Mo of 0.1-2.0 percentage by weight of 0.1-0.8 percentage by weight, and the particle mean size that wherein is used for the material powder of sintering is 20 μ m or below the 20 μ m.Described powder can further contain at least a element among the following P of following Si of 2 percentage by weights or 2 percentage by weights following Cu, 1 percentage by weight or 1 percentage by weight following Ti, 1 percentage by weight or 1 percentage by weight following Al, 1 percentage by weight or 1 percentage by weight following Mn, 1 percentage by weight or 1 percentage by weight and 1 percentage by weight or 1 percentage by weight, and wherein nearly the iron content of 5 percentage by weights can be by the one or more replacements in these elements.Even the sinter-hardening powder that discloses among the present invention also can harden to blank sintering HRC30 or the hardness more than the HRC30 through the slow speed cooling with 3 ℃/min behind the sintering.
Ni can produce high hardenability and also can give element with high tenacity and percentage elongation to sintered body.And, comparing with other alloying element of great majority of for example Cu, Mo, Cr, Mn and Si, Ni is a very effective additive aspect the sintered density of improving the steel billet body and toughness.Therefore, it is favourable adding Ni in sinter-hardening powder.In the present invention, preferred Ni content is between 5 percentage by weights and 12.0 percentage by weights, because sinter-hardened characteristic is not obvious when Ni content is lower than 5 percentage by weights, or when Ni content is higher than 12 percentage by weights, because after sintering, will keep too much austenite, so sinter-hardened effect weakens.On the other hand, when Ni content during greater than 12 percentage by weights, the benefit of acquisition is limited, and the cost of sintered part(s) increases.
The distribution of Ni in the sintered steel is because its slow diffusion rate in iron and inhomogeneous usually.Another reason is that carbon has fast diffusion rate in iron, but and therefore quick penetration enter the core of iron powder.When Ni when the iron powder core spreads, because carbon has increased the chemical potential of Ni, so carbon tends to repel entering of Ni.Therefore, in Fe matrix, be difficult to the Ni that homogenizes, and therefore, its sinter-hardened benefit loss.So its intensity of zone and the hardness of the high ni content that forms are lower, and when becoming part and using in heavily stressed fragile down position.Yet the present invention finds that the repulsive interaction between Ni and the C alleviates when Cr exists, and the distribution of Ni becomes more evenly, and this has used X ray to draw and prove.Distribute and the elimination in the zone of soft high ni content by Ni uniformly, the total hardness of sintered body and intensity will increase.
The chromium content that uses among the present invention is between 0.1 percentage by weight and 2 percentage by weights.Cr is during less than 0.1 percentage by weight, and the hardenability effect is unimportant.When Cr content surpasses 2 percentage by weights, martensitic amount will reduce.The interpolation of Cr can be adopted the siderochrome powder or contain other alloying element and add in other interior complicated siderochrome form of powder.As mentioned above, this will reduce the active of Cr and guarantee that it does not form chromium oxide during sintering, therefore can keep Ni is solidly soluted into validity in the ferrous substrate.Yet the amount of required Cr depends on the granularity of iron powder and the content of the Ni that uses.
Table 2 and Fig. 1 show, by using fine carbonyl iron powder to add other element powder or alloy powder as basic powder and according to the composition of Fe-8Ni-0.8Mo-xCr-0.5C (x changes to 3 percentage by weights from 0), and use metal injection moulding technology, the hardness of the sample of sinter-hardened and tempering at first increases along with the increase of Cr, when about 0.7 percentage by weight, reach maximum, and increase along with the amount of Cr subsequently and reduce.The amount of Cr that this means 3 percentage by weights is too big for the homogenizing of Ni, because hardness is lower than HRC30.Yet when using the crude iron powder as basic powder, the difficulty that becomes homogenizes.Therefore, the homogenize amount of the required Cr of Ni increases.By using thick water-atomized iron powder end (particle mean size) and add other element powder or alloy powder, and use the effect of provable this meal of compacting sintering process according to the composition of Fe-4Ni-0.5Mo-0.5C with 75 μ m.Table 2 and Fig. 2 show that hardness at first increases along with the increase of Cr, reach maximum when the Cr of about 3 percentage by weights, and increase along with the amount of Cr subsequently and reduce.These examples show, for Ni homogenize and optimum Cr content that hardness is required increases and increases along with the granularity of iron powder.Reason is, under the situation of thicker base iron powder, and the good homogenieity that needs long time or higher temperature obtain alloying element.Except the granularity effect, optimum Cr content further depends on the amount of Ni in the sintered body.These examples prove, for obtaining high rigidity, need the composition of alloying element to have only a narrow range, (in for example above-mentioned example at iron particle size of selecting among the present invention and Ni amount).
Table 2 displaying Fe powder degree and Ni content are to the influence of the optimum Cr content of Fe-8Ni-0.8Mo-0.5C and Fe-4Ni-0.5Mo-0.5C.
Table 2
When design casting or wrought alloy bulk or pre-alloyed powder, the optimum content of alloying element will be than low in the mixed-powder, because realized homogenizing of various alloying elements between melting stage.Casting and another reason than low-alloy content of wrought alloy be, raw material must be enough soft so that can carry out plastic deformation (for example, extruding forging) and other secondary operation (for example, machining) to satisfy the size standard of part.Obtain optimum engineering properties with quenching and temper more subsequently.By contrast, compacting sintering and MIM technology are clean forming technology (net shaping).Therefore, the part after sintering has obtained that size should be arranged, this moment if part can through sinter-hardened and further Quenching Treatment can to obtain high rigidity will be an individual advantage.This has eliminated the frequent defective that forms during quenching.The elimination of quenching technical makes sinter-hardened material more economical and more competitive.Therefore, the optimum that designs at the sinter-hardening powder that is used for compacting sintering and MIM product among the present invention is formed and is careful design, and is different from AISI and MPIF standard alloy steel and those and has the pre-alloyed powder of patent.Being chosen in of narrow compositing range that discloses among the present invention and powder produces new and unexpected aspect as a result is effective.
Molybdenum is another effective alloying element, and the amount of using among the present invention is between 0.1 percentage by weight and 2 percentage by weights.When Mo content surpasses 2 percentage by weights, because the martensitic quantity not sufficient that produces in the sintered part(s), hardness will reduce.And molybdenum also is expensive element.Under the situation of adding too much Mo, it is too high that the cost of sintered products will become, and therefore feasible comparing with those homologues of making by other manufacturing process do not have competitiveness.The interpolation of Mo can be added molybdenum with pure Mo powder, iron molybdenum powder or the form that contains the complicated iron molybdenum pre-alloyed powder of other alloying element.
Manganese has very high hardenability, and only needs a small amount of.The amount of the Mn that uses among the present invention is less than 1 percentage by weight.When the amount of Mn surpassed 1 percentage by weight, it is really up to the mark, crisp excessively that material becomes.In order to reduce its activity and to prevent to form oxide during the sintering, the interpolation of Mn can be used the ferrimanganic form of powder, and described ferrimanganic powder can further contain other alloying element.
Silicon also has high hardenability, and only needs on a small quantity, and the amount of using among the present invention is less than 1 percentage by weight.When Si content surpassed 1 percentage by weight, sintered body became crisp and was not suitable for constitutional detail.In order to reduce the active of Si and to prevent that oxide from forming, the interpolation of Si can be used the form of iron Si powder, and described iron Si powder can further contain other alloying element.
Most economical and effective hardening element is a carbon.For example in most of compacting sintering powdered metal parts and in some MIM parts, can supply carbon, also can supply carbon from carbon black powders from powdered graphite.The interpolation of graphite or carbon black has increased extra treatment step and has therefore increased cost.Therefore, the fine carbonyl iron powder of carbon containing can be used as the preferred basic powder among the present invention, but also can use carbon-free carbonyl iron powder, and then must add graphite or carbon black this moment.Owing to contain carbon in the carbonyl iron powder, so its carbon is distributed in the sintered part(s) in heterogeneity.And the carbon in the carbonyl iron powder is not with the hard cementite (Fe of matter
3C, form cementite) exists, when therefore being used in compacting sintering technology, with the compressible adverse effect that can not cause powder.
The interpolation of the above alloying element can the element powders form or is added with the alloy powder form.When adding with the alloy powder form, this alloy powder can contain two or more elements, and can iron be that prealloy (ferrous prealloyed) powder or foundry alloy (master alloy) form of powder are added base iron powder to.
In order to realize high strength, high rigidity and high sintered density simultaneously, the selection For several reasons of basic powder is crucial.For instance, attritive powder has big surface area, and it is the driving force that is used for sintering, therefore can obtain high sintered density.In addition, because the shorter diffusion length of attritive powder, homogenizing of alloying element is also very fast.Therefore, preferred in the present invention fine powder.Aspect the type of basic powder, promptly element powders or pre-alloyed powder also are important.Select low-cost iron powder (for example atomize, reduction and carbonyl iron powder) as the basic powder among the present invention based on using the shortcoming of pre-alloyed powder as basic powder, the present invention in aforesaid consideration and the previous technology.When the alloying element with careful selection mixes with the amount of careful design, can obtain to compare improvement many engineering properties and sintered density with using pre-alloyed powder.
Example 1
The Fe-0.8Mo-0.8Cr mixed-powder is added the element Ni powder of different amounts.Selected base iron powder is a carbonyl iron powder.Add the Mo powder with the element powders form.Form with Fe-16 percentage by weight Cr ferroalloy powder (Fe-16wt%Cr ferroalloy powder) is added Cr.Show chemical composition in the table 3.The binding agent of mixed-powder and 7 percentage by weights mixes, in the high-rate of shear muller, under 150 ℃, mixed 1 hour, and subsequently cool to room temperature to obtain graininess shoot material (feedstock).Subsequently, graininess is shot material be filled in the injection machine to produce the tensile test bar standard tensile coupon of MPIF-50 standard (for example, from).Under the program that known technology from industry is used, the tensile test bar binding agent is removed, in vacuum drying oven, heated two hours down subsequently, and carry out the stove cooling with about 6 ℃/minute cooldown rate (between 600 ℃ and 300 ℃, recording) subsequently at 1200 ℃.After sintering, under 200 ℃ with sample tempering 2 hours.The carbon content that obtains is about 0.48 percentage by weight, and sintered density is about 95.7%.Hardness increases and increases along with Ni content, reaches maximum when the Ni of about 8 percentage by weights.
Table 3 is showed the influence of Ni content to the hardness of sinter-hardened Fe-0.8Mo-0.8Cr-0.48C base substrate.
Table 3
| Catalogue number(Cat.No.) | Ni (percentage by weight) | Hardness (HRC) |
| ??1 | ??0 | ??14 |
| ??2 | ??1 | ??18 |
| ??3 | ??2 | ??20 |
| ??4 | ??4 | ??32 |
| ??5 | ??5 | ??39 |
| ??6 | ??6 | ??44 |
| ??7 | ??8 | ??48 |
| ??8 | ??10 | ??45 |
| ??9 | ??12 | ??37 |
Example 2
The Fe-8Ni-0.8Cr mixed-powder is added the elements Mo powder of different amounts.Selected base iron powder is a carbonyl iron powder.Form with Fe-16 percentage by weight Cr ferroalloy powder is added Cr, adds Ni with the element powders form simultaneously.Table 4 is showed chemical composition.Following those routine processes of describing in the example 1 shoots material.Therefore the carbon content that obtains behind the sintering is about 0.45 percentage by weight, and sintered density is about 95.7%.As shown in table 4, hardness increases and increases along with Mo content, reaches maximum when the Mo of about 0.8 percentage by weight.When Mo content was 6 percentage by weights, hardness was reduced to HRC35.
Table 4 is showed the influence of Mo content to the hardness of sinter-hardened Fe-8Ni-0.8Cr-0.45C base substrate.
Table 4
| Catalogue number(Cat.No.) | Mo (percentage by weight) | Hardness (HRC) |
| ??10 | ??0 | ??40 |
| ??11 | ??0.1 | ??42 |
| ??12 | ??0.5 | ??46 |
| ??13 | ??0.8 | ??48 |
| ??14 | ??2 | ??43 |
| ??15 | ??4 | ??39 |
| Catalogue number(Cat.No.) | Mo (percentage by weight) | Hardness (HRC) |
| ??16 | ??6 | ??35 |
Example 3
The Fe-8Ni-0.8Mo mixed-powder is added the Cr of different amounts with the form of Fe-16 percentage by weight Cr ferroalloy powder.Selected base iron powder is a carbonyl iron powder.Add Ni and Mo with the element powders form.Table 5 is showed chemical composition.With with example 1 in describe identical mode and handle and shoot material.Therefore the carbon content that obtains behind the sintering is about 0.43 percentage by weight, and sintered density is about 95.6%.As shown in table 5, hardness increases and increases along with Cr content, reaches maximum when the Cr of about 0.8 percentage by weight.When Cr content was 6 percentage by weights, hardness was reduced to HRC30.
Table 5 is showed the influence of Cr content to the hardness of sinter-hardened Fe-8Ni-0.8Mo-0.43C base substrate.
Table 5
| Catalogue number(Cat.No.) | Cr (percentage by weight) | Hardness (HRC) |
| ??17 | ??0 | ??42 |
| ??18 | ??0.1 | ??43 |
| ??19 | ??0.2 | ??45 |
| ??20 | ??0.5 | ??48 |
| ??21 | ??0.8 | ??48 |
| ??22 | ??1.5 | ??46 |
| ??23 | ??2.0 | ??42 |
| ??24 | ??3.0 | ??37 |
| ??25 | ??6.0 | ??30 |
More than show that in table 5 Fe-8Ni-0.8Mo-0.43C adds the benefit of Cr.Yet, just visible this type of benefit when having the good combination of alloying element only.For instance, Fe-8Ni-0.5C has the sintering hardness of HRC 42.When adding the Cr of 0.5 percentage by weight, hardness is reduced to HRC40.The further inspection of intensity also showed from 1750MPa be reduced to 1500MPa.This indication Cr does not increase the hardness of Fe-8Ni-0.5C, unless Mo exists.
Example 4
The Fe-8Ni-0.8Mo-0.8Cr mixed-powder is added the Mn of different amounts with the form of Fe-Mn ferroalloy powder.Form with Fe-16 percentage by weight Cr ferroalloy powder is added Cr.Selected base iron powder is a carbonyl iron powder.Add Ni and Mo with the element powders form.Table 6 is showed chemical composition.With with example 1 in describe identical mode and handle and shoot material.Therefore the carbon content that obtains behind the sintering is about 0.52 percentage by weight, and sintered density is about 95.5%.As shown in table 6, hardness increases along with Mn content and reduces a little.This indication is generally comprised within the sinter-hardening powder that the interpolation of the Mn in pre-alloyed powder and the mo(u)lded piece discloses in the present invention unimportant with regard to hardness.Yet along with Mn content increases, hot strength is higher slightly than the hot strength of the base substrate that does not contain Mn.Application and required character are depended in this indication, and the interpolation of Mn can not cause adverse influence.
Table 6 shows that Mn content is to the hardness of sinter-hardened Fe-8Ni-0.8Mo-0.8Cr-0.52C base substrate and the influence of hot strength.
Table 6
| Catalogue number(Cat.No.) | Mn (percentage by weight) | Hardness (HRC) | Hot strength (MPa) |
| ??26 | ??0 | ??48 | ??1970 |
| ??27 | ??0.2 | ??46 | ??2000 |
| ??28 | ??0.3 | ??46 | ??1980 |
| ??29 | ??0.4 | ??46 | ??1970 |
| ??30 | ??0.6 | ??45 | ??1980 |
| ??31 | ??1.0 | ??45 | ??1980 |
Example 5
Form with Fe-20 percentage by weight Si iron (Fe-20%Si ferroalloy powder) alloy powder is added the Si of different amounts to the Fe-8Ni-0.8Mo-0.8Cr mixed-powder, adds Cr with the form of Fe-16 percentage by weight Cr ferroalloy powder.Selected base iron powder is a carbonyl iron powder.Add Ni and Mo with the element powders form.Table 7 is showed chemical composition.With with example 1 in describe identical mode and handle and shoot material.Therefore the carbon content that obtains behind the sintering is about 0.50 percentage by weight.When silicone content was increased to 1 percentage by weight, sintered density was reduced to 95.0% a little from 95.7%.Therefore, hardness also reduces a little.This indication is generally comprised within the sinter-hardening powder that the interpolation of the Si in pre-alloyed powder and the mo(u)lded piece discloses in the present invention unimportant.Yet during up to 1 percentage by weight, sintered body still can obtain the hardness greater than HRC45 at silicone content.
Table 7 is showed the influence of Si content to the hardness of sinter-hardened Fe-8Ni-0.8Mo-0.8Cr-0.50C base substrate.
Table 7
| Catalogue number(Cat.No.) | Si (percentage by weight) | Hardness (HRC) |
| ??32 | ??0 | ??48 |
| ??33 | ??0.2 | ??48 |
| ??34 | ??0.3 | ??47 |
| ??35 | ??0.4 | ??46 |
| Catalogue number(Cat.No.) | Si (percentage by weight) | Hardness (HRC) |
| ??36 | ??0.6 | ??46 |
| ??37 | ??1.0 | ??45 |
Example 6
The Fe-8Ni-0.8Mo-0.8Cr mixed-powder is added the Cu of different amounts with the form of element powders.Form with the Fe-Cr ferroalloy powder is added Cr.Selected base iron powder is a carbonyl iron powder.Add Ni and Mo with the element powders form.Table 8 is showed chemical composition.With with example 1 in describe identical mode and handle and shoot material.Therefore the carbon content that obtains behind the sintering is about 0.51 percentage by weight, and sintered density is about 95.6%.As shown in table 8, hardness increases along with Cu content and reduces a little.Yet when being increased to about 0.3 percentage by weight along with Cu content, hot strength is increased to peak.It reduces subsequently, and begins to be reduced to and the similar level of hot strength that does not contain the tensile test bar of Cu when Cu content reaches 1.5 percentage by weights.Required character is depended in this indication, and the interpolation of Cu can have active influence.
Table 8 shows that Cu content is to the hardness of sinter-hardened Fe-8Ni-0.8Mo-0.8Cr-0.51C base substrate and the influence of hot strength.
Table 8
| Catalogue number(Cat.No.) | Cu (percentage by weight) | Hardness (HRC) | Hot strength (MPa) |
| ??38 | ??0 | ??48 | ??1970 |
| ??39 | ??0.3 | ??46 | ??2060 |
| ??40 | ??0.5 | ??46 | ??2010 |
| ??41 | ??1.0 | ??45 | ??2010 |
| ??42 | ??1.5 | ??45 | ??1970 |
Example 7
Handling the Fe-8Ni-0.8Mo-0.8Cr powder with example 1 described identical mode, but sintering temperature is 1320 ℃.The carbon content that obtains behind the sintering is about 0.42 percentage by weight, and sintered density is about 96.6%.Hardness after the tempering is HRC 47, and is similar with the HRC48 of 1190 ℃ of following sintered compacts.The hot strength that records is 2010MPa, is higher than the 1970MPa that obtains at 1190 ℃ of following sintering a little.At the percentage elongation of the tensile test bar of 1190 ℃ and 1320 ℃ following sintering be respectively percentage 3.4 and percentage 4.1.These hot strengths are showing and are being better than to so far about the data of metal injection moulding or compacting sintering part report.Described percentage elongation also is very enough for the application in the constitutional detail.The example that table 1 provides in 8 illustrates the sinter-hardened effect of material powder of the present invention.
Example 8
Handling the Fe-8Ni-0.8Mo-0.8Cr powder, but use graphite and carbon black powders as carbon source with example 1 described identical mode.Carbon-free carbonyl iron powder (as carbonyl iron dust annealed under hydrogeneous atmosphere) is used as basic powder.Carbon content, density and hardness and the use carbonyl iron powder that produces is similar as carbon content, density and hardness that carbon source obtains.
Example 9
Handling the Fe-8Ni-0.8Mo-0.8Cr-0.45C powder with example 1 described identical mode, but cooldown rate changes.Table 9 show have 3 ℃/minute, the sintered body of the cooldown rate of 6 ℃/minute and 30 ℃/minute has the similar hardness of about HRC 48 after tempering.When base substrate being quenched in water and tempering, hardness is 51.This proves that constituent of the present invention produces very high hardenability, even and in that reach slowly also can sinter-hardened base substrate under 3 ℃/minute the cooldown rate.
Table 9 is showed the influence of cooldown rate to the hardness of the Fe-8Ni-0.8Mo-0.8Cr-0.45C base substrate of sinter-hardened and tempering.
Table 9
| Catalogue number(Cat.No.) | Cooldown rate ℃/minute | Hardness HRC |
| ??43 | ??3 | ??47 |
| ??44 | ??6 | ??48 |
| ??45 | ??30 | ??48 |
| ??46 | Quench | ??51 |
Example 10
The composition of the sinter-hardening powder that discloses among the present invention is the result of the optimum combination of alloying element.Table 10 is listed the hardness of the base substrate (catalogue number(Cat.No.) 47 to 57) of some other MIM sintering that use the sinter-hardening powder that discloses among the present invention and tempering.Also preparation has the compacting sintering base substrate of the composition of Fe-8Ni-0.8Cr-0.8Mo-0.4C.Carbonyl iron powder and elements Mo and Ni powder and Fe-Cr ferroalloy powder are mixed together.Mixed-powder, water and binding agent (for example, polyvinyl alcohol) blending is slurries.Subsequently with the described slurries of high rotation speed nozzle atomization, and with the hot-air drying with evaporation water wherein.Therefore by binding agent with the attritive powder particulate powder that has good fluidity with formation bonded to one another.The granularity of particulate powder is about 40 μ m.Particulate powder is filled in the mold cavity to use press to produce the pressed compact tensile test bar.With the program that known technology from industry is used the binding agent in the tensile test bar is removed.After 1200 ℃ of following sintering 1 hour, base substrate is carried out the stove cooling, and subsequently 180 ℃ of following tempering 2 hours.Sinter-hardened tensile test bar has the tensile strength of 1690MPa, the hardness of HRC47 and 3% ductility.The sinter-hardening powder that discloses among the present invention of these examples show can be used for making the sintered body with improved hardness and does not have unsuitable ductility loss.Use the MIM method and use the compacting sintering method all can provide similar sintering property about mixed-powder about particulate powder.This expects, because the metal dust that uses in these two methods is identical.
Table 10 shows to have some sintering of the composition (percentage by weight) that discloses among the present invention and the character of tempering base substrate.
Table 10
| Catalogue number(Cat.No.) | ??C | ??Ni | ??Mo | ??Cr | ??Si | ??Mn | Other | ??Fe | Hardness HRC | Hot strength MPa | Percentage elongation % |
| ??47 | ??0.36 | ??8.0 | ??0.8 | ??08 | ??0.3 | ??0.6 | Remainder | ??45 | ??1800 | ??3 | |
| ??48 | ??0.34 | ??9.0 | ??0.8 | ??0.8 | ??- | Remainder | ??45 | ??1780 | ??4 | ||
| ??49 | ??0.40 | ??7.5 | ??0.8 | ??0.5 | ??0.3 | ??- | Remainder | ??43 | ??1750 | ??4 | |
| ??50 | ??0.6 | ??8.0 | ??0.8 | ??0.8 | ??0.3 | ??- | Remainder | ??48 | ??2010 | ??2 | |
| ??51 | ??0.8 | ??8.0 | ??0.8 | ??0.8 | ??0.3 | ??- | ??- | Remainder | ??35 | ??1550 | ??3 |
| ??52 | ??0.4 | ??8.0 | ??0.8 | ??0.8 | ??- | ??0.3Cu | Remainder | ??46 | ??1950 | ??3 | |
| ??53 | ??0.5 | ??8.0 | ??0.8 | ??0.8 | ??0.2 | ??0.4 | ??- | Remainder | ??48 | ??1920 | ??4 |
| ??54 | ??0.4 | ??8.0 | ??1.0 | ??0.8 | ??0.2 | ??- | ??0.4V，1.2W | Remainder | ??46 | ??1960 | ??4 |
| ??55 | ??0.3 | ??12.0 | ??2.0 | ??2.0 | ??0.3 | ??- | ??- | Remainder | ??37 | ??1560 | ??6 |
| ??56 | ??0.4 | ??6 | ??0.5 | ??0.2 | ??0.2 | ??- | ??1.5Cu | Remainder | ??35 | ??1500 | ??2 |
| ??57 | ??0.5 | ??5.0 | ??1.5 | ??0.8 | ??- | ??- | Remainder | ??48 | ??1740 | ??4 |
Comparative Example
In order to compare, table 11 is showed the composition and the character of the Comparative Example of using the preparation of metal injection moulding technology.The MIM 4605 that lists in MPI F standard (catalogue number(Cat.No.) 58) has the intensity of 440MPa after sintering.After quenching and tempering, intensity is that 1655MPa and percentage elongation are 2% (catalogue number(Cat.No.)s 59).MIM 2700 standards (catalogue number(Cat.No.) 60) produce the intensity of 415MPa and the hardness of HRB69 (too soft and can't measure) in the HRC level.No. 62 samples and No. 67 samples have the 7th, 163, the composition that discloses in No. 569 United States Patent (USP)s.The hardness of these two parts and hot strength are lower than hardness and the hot strength of using the sinter-hardening powder acquisition that discloses among the present invention.No. 70 samples have the composition according to the SCM415 of Japanese Industrial Standards.The hardness of sintered body is lower than HRC20.No. 71 sample has the composition identical with AISI4140.And the hardness that obtains is HRC21.No. 72 samples are followed the composition of SAE 8740, and the hardness of sintered body is HRC27.
Table 11 is showed the composition (percentage by weight) and the character of Comparative Example.
Table 11
| Comparative catalogue number(Cat.No.) | The Ni percentage by weight | The Mo percentage by weight | The Mn percentage by weight | The Si percentage by weight | The Cr percentage by weight | Other percentage by weight | The C percentage by weight | Hardness | Hot strength MPa | Percentage elongation % |
| ??58MIM??4605 | ??2.0 | ??0.35 | ??- | ??＜1.0 | ??- | ??- | ??0.5 | ??HRB62 | ??440 | ??15 |
| ??59??MIM4605 (1) | ??2.0 | ??0.35 | ??- | ??＜1.0 | ??- | ??- | ??0.5 | ??HRC48 | ??1655 | ??2 |
| ??60MIM2700 | ??7.5 | ??＜0.5 | ??- | ??＜0.1 | ??- | ??- | ??＜0.1 | ??HRB69 | ??415 | ??26 |
| ??61 | ??1.75 | ??1.0 | ??- | ??0.3 | ??- | ??- | ??0.35 | ??HRC10 | ??650 | ??9 |
| ??62 (2) | ??1.75 | ??2.0 | ??- | ??0.3 | ??- | ??0.5Nb | ??0.34 | ??HRC20 | ??820 | ??8 |
| ??63 | ??1.75 | ??5.0 | ??0.3 | ??- | ??0.32 | ??HRC25 | ??1050 | ??6 | ||
| ??64 | ??2.0 | ??0.8 | ??0.6 | ??0.3 | ??0.8 | ??- | ??0.45 | ??HRC29 | ??1120 | ??4 |
| ??65 | ??2.0 | ??0.8 | ??0.8 | ???- | ??- | ??0.45 | ??HRC21 | ??990 | ??7 | |
| ??66 | ??2.0 | ??0.8 | ??- | ??0.3 | ???- | ??- | ??0.45 | ??HRC11 | ??720 | ??8 |
| ??67 (2) | ??4.0 | ??- | ??- | ??0.3 | ???- | ??0.8Nb | ??0.45 | ??HRB86 | ??583 | ??5 |
| ??68 | ??4.0 | ??0.8 | ??0.3 | ???- | ??- | ??0.6 | ??HRC35 | ??1130 | ??3 | |
| ??69 | ??4.0 | ??0.8 | ??- | ??0.3 | ??0.8 | ??- | ??0.53 | ??HRC40 | ??1270 | ??6 |
| ??70SCM415 | ??0.08 | ??0.22 | ??0.7 | ??0.3 | ??1.05 | ??- | ??0.18 | ??＜HRC20 | ??＞410 | ??＞15％ |
| ??71??AISI4140 | ??- | ??0.21 | ??0.8 | ??0.23 | ??0.96 | ??- | ??0.56 | ??HRC21 | ||
| ??72SAE8740 | ??0.64 | ??0.31 | ??0.09 | ??0.45 | ??0.49 | ??- | ??0.26 | ??HRC27 | ??880 | ??12 |
| ??73 | ??6.96 | ??- | ??0.04 | ??0.21 | ??0.01 | ??- | ??0.26 | ??HRC27 | ??880 | ??12 |
Note: 1. after quenching and tempering.
2. disclose in the 7th, 163, No. 569 United States Patent (USP)s.
More than describe and reach a conclusion, the sinter-hardened constituent in the sintered body of the present invention can obtain the hardness higher than HRC30 easily through the stove cooling.Best sinter-hardened alloy of listing with MPIF that is used for the compacting sintering workpiece (needing to use minimum 30 ℃/minute high cooldown rate) or optimal injection shaping alloy MIM-4605 (quench and tempering after) compare, sinter-hardened constituent of the present invention can obtain similarly or even better engineering properties under the situation that quench-hardening handles need not.In addition, can avoid the problem that draws from quenching of the prior art or quench-hardening in the present invention, comprise distortion, size is inconsistent and quench after break etc., and can eliminate the cost of quench hardening technology or high cooldown rate device.Although sinter-hardened alloy can be used for traditional compacting sintering technology, the required cooldown rate of sintering main body is higher than 30 ℃/minute.By contrast, the required cooldown rate of constituent of the present invention can be lower than 30 ℃/minute.Sintering main body of the present invention provides good mechanical shape matter, and it also provides the advantage of the good and lower cost aspect of size Control.
Because the combination of the careful selection of the alloying element of basic powder and optimal amount and type the invention solves problem mentioned above.Mixture of powders or particulate powder use elemental iron powder (for example, atomizing, reduction or carbonyl iron powder) as basic powder.Particle mean size is 20 μ m or below the 20 μ m.Alloying element comprises C, the Ni of 5.0-12.0 percentage by weight, the Cr of 0.1-2.0 percentage by weight, the Mo of 0.1-2.0 percentage by weight of 0.1-0.8 percentage by weight.More than form at least a other less important intensified element that can further contain the amount below 5.0 percentage by weights or 5.0 percentage by weights.The group that the optional free Cu of intensified element, Mn, Si, Ti, Al and P form.Can be by adding graphite or carbon black or using the carbonyl iron powder of carbon containing that carbon is provided.Described mixed-powder can be used for the manufacturing of MIM base substrate.Described particulate powder can be used for the manufacturing of compacting sintering base substrate.In addition, the present invention provides sintered body by using mixture of powders or particulate powder.Can need not to use quick cooling with the sinter-hardened described base substrate of normal stove cooldown rate below 30 ℃/minute in sintering furnace, other sinter-hardening powder needs described quick cooling.Sintered body is also without any need for Quenching Treatment.Only need lonneal to obtain optimum engineering properties.Sintering main body with sinter-hardening powder mentioned above has unexpected hardness, hot strength and good ductility.Owing to do not need quenching technical or expensive high cooldown rate device, so manufacturing cost is lower.Because the elimination of for example crackle that takes place during quenching and the defective of distortion also can obtain higher production yield.
In actual applications, sinter-hardened material powder granulation can be become the particulate powder that is used for compacting sintering.Although the particle mean size of material powder is 20 μ m or below the 20 μ m, the particle mean size of particulate powder can be for example between the 20-150 μ m.In addition, material powder or particulate powder can be used for creating sintered body.
The above, it only is preferred embodiment of the present invention, be not that the present invention is done any pro forma restriction, though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention, any those skilled in the art, in not breaking away from the technical solution of the present invention scope, when the technology contents that can utilize above-mentioned announcement is made a little change or is modified to the equivalent embodiment of equivalent variations, in every case be the content that does not break away from technical solution of the present invention, according to technical spirit of the present invention to any simple modification that above embodiment did, equivalent variations and modification all still belong in the scope of technical solution of the present invention.
Claims (13)
1. sinter-hardened material powder, it comprises the main constituent of iron conduct and further comprises the carbon of 0.1 to 0.8 percentage by weight, the nickel of 5.0 to 12.0 percentage by weights, the chromium of 0.1 to 2.0 percentage by weight and the molybdenum of 0.1 to 2.0 percentage by weight, the wherein said particle mean size that is used for the material powder of sintering is 20 μ m or below the 20 μ m, and this sinter-hardened powder is to be that prealloy powder is basic powder with iron powder or carbonyl iron dust or carbon, iron that nickel content is low.
2. sinter-hardened material powder according to claim 1, it further contains at least a element in the following phosphorus of following silicon of following manganese 1 percentage by weight of 2 percentage by weights or 2 percentage by weights following copper, 1 percentage by weight or 1 percentage by weight following titanium, 1 percentage by weight or 1 percentage by weight following aluminium, 1 percentage by weight or 1 percentage by weight or 1 percentage by weight and 1 percentage by weight or 1 percentage by weight.
3. sinter-hardened material powder according to claim 1, it contains the carbon of 0.3 to 0.7 percentage by weight, the nickel of 6.0 to 10.0 percentage by weights, the chromium of 0.3 to 1.5 percentage by weight, the molybdenum of 0.2 to 1.0 percentage by weight.
4. sinter-hardened material powder according to claim 2, it contains the copper of 0.1 to 1.0 percentage by weight, the manganese of 0.2 to 0.8 percentage by weight and the silicon of 0.1 to 0.5 percentage by weight.
5. sinter-hardened material powder according to claim 1, the source of wherein said carbon are the carbonyl iron powder from carbon containing.
6. sinter-hardened material powder according to claim 1, the source of wherein said carbon is from carbon black powders.
7. sinter-hardened material powder according to claim 1, the source of wherein said carbon is from powdered graphite.
8. sinter-hardened material powder according to claim 1, wherein said material powder are element powders or ferroalloy powder or described both mixture.
9. sinter-hardened material powder according to claim 1, wherein said iron is from carbonyl iron powder.
10. sinter-hardened material powder according to claim 1, wherein said iron are from the atomized iron powder end.
11. sinter-hardened material powder according to claim 1, wherein said iron are from the reduced iron powder.
12. being the content of its carbon of prealloy powder and nickel, sinter-hardened material powder according to claim 1, wherein said carbon, the iron that nickel content is low be lower than 0.1 percentage by weight.
13. it comprises the composition of sinter-hardening powder according to claim 1 a sintered body.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US12/366,624 US20090142219A1 (en) | 2004-06-10 | 2009-02-05 | Sinter-hardening powder and their sintered compacts |
| US12/366,624 | 2009-02-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101797641A true CN101797641A (en) | 2010-08-11 |
Family
ID=42593566
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN200910143017A Pending CN101797641A (en) | 2009-02-05 | 2009-05-22 | Sinter hardening raw material powder and sintered body thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101797641A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104862698A (en) * | 2015-06-02 | 2015-08-26 | 贵州大学 | Coating material and coating with high contact fatigue strength based on 304 stainless steel base material |
| CN106111994A (en) * | 2016-02-12 | 2016-11-16 | Nep有限公司 | Use the method that ferrous metal nodular powder manufactures ferrous metal part |
| CN107008909A (en) * | 2017-03-27 | 2017-08-04 | 刘金财 | A kind of preparation method of high-precision powder metallurgical gear |
| US9962765B2 (en) | 2012-07-31 | 2018-05-08 | Taiwan Powder Technologies Co., Ltd. | Method of producing workpiece and workpiece thereof |
| CN108907212A (en) * | 2018-08-01 | 2018-11-30 | 湖南菲德克材料科技有限公司 | A method of Maraging steel is prepared based on injection moulding |
| CN109202067A (en) * | 2017-11-10 | 2019-01-15 | 宁波市鄞州业鑫汽车零部件有限公司 | It is a kind of that the sinter-hardened process of powder metallurgy product is realized using normal sintering furnace |
-
2009
- 2009-05-22 CN CN200910143017A patent/CN101797641A/en active Pending
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US9962765B2 (en) | 2012-07-31 | 2018-05-08 | Taiwan Powder Technologies Co., Ltd. | Method of producing workpiece and workpiece thereof |
| CN104862698A (en) * | 2015-06-02 | 2015-08-26 | 贵州大学 | Coating material and coating with high contact fatigue strength based on 304 stainless steel base material |
| CN106111994A (en) * | 2016-02-12 | 2016-11-16 | Nep有限公司 | Use the method that ferrous metal nodular powder manufactures ferrous metal part |
| CN106111994B (en) * | 2016-02-12 | 2018-05-18 | Nep有限公司 | Use the method for ferrous metal nodular powder manufacture ferrous metal part |
| CN107008909A (en) * | 2017-03-27 | 2017-08-04 | 刘金财 | A kind of preparation method of high-precision powder metallurgical gear |
| CN109202067A (en) * | 2017-11-10 | 2019-01-15 | 宁波市鄞州业鑫汽车零部件有限公司 | It is a kind of that the sinter-hardened process of powder metallurgy product is realized using normal sintering furnace |
| CN108907212A (en) * | 2018-08-01 | 2018-11-30 | 湖南菲德克材料科技有限公司 | A method of Maraging steel is prepared based on injection moulding |
| CN108907212B (en) * | 2018-08-01 | 2020-07-24 | 湖南菲德克材料科技有限公司 | Method for preparing maraging steel based on injection molding |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20220119927A1 (en) | Wear resistant alloy | |
| CN1662327B (en) | Prealloyed iron-based powder, a method of producing sintered components and a component | |
| EP2155921B1 (en) | Iron-based powder and composition thereof | |
| CN101069927B (en) | Sinter-hardening powder and their sintered compacts | |
| US20050274222A1 (en) | Method for making sintered body with metal powder and sintered body prepared therefrom | |
| CN100475389C (en) | Sintered metal parts and method for the manufacturing thereof | |
| EP1536027A1 (en) | Raw or granulated powder for sintering, and sintered compacts therefrom | |
| CN102933731B (en) | The manufacturing process of a kind of master alloy for the manufacture of sintering-hardened steel part and this sinter-hardened part | |
| CN105339517A (en) | Method for producing a steel shaped body | |
| TW201107495A (en) | High strength low alloyed sintered steel | |
| JPH05117703A (en) | Iron-base powder composition for powder metallurgy, its production and production of iron-base sintering material | |
| CN101925684A (en) | Low alloyed steel powder | |
| CN102361997A (en) | Iron vanadium powder alloy | |
| CN101797641A (en) | Sinter hardening raw material powder and sintered body thereof | |
| US20100196188A1 (en) | Method of producing a steel moulding | |
| US20090142219A1 (en) | Sinter-hardening powder and their sintered compacts | |
| CN101925683A (en) | Low alloyed steel powder | |
| CN101952470A (en) | Powder for iron-based sintered alloy | |
| CN101797640A (en) | Sinter-hardening powder and their sintered compacts | |
| CN102884215A (en) | Steel with high temper resistance | |
| US11248284B2 (en) | Non-magnetic austenitic steel with good corrosion resistance and high hardness | |
| JP2000509440A (en) | Method for producing metal powder products by sintering, spheroidizing and warm forming | |
| CN101258258A (en) | Powder metallurgically manufactured high speed steel | |
| JP5929084B2 (en) | Alloy steel powder for powder metallurgy, iron-based sintered material and method for producing the same | |
| SE542360C2 (en) | A steel powder, a product comprised by an aggregate thereof, and use of such steel powder |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C02 | Deemed withdrawal of patent application after publication (patent law 2001) | ||
| WD01 | Invention patent application deemed withdrawn after publication |
Open date: 20100811 |