CN108097967A - A kind of method that diffusion-sintering prepares Fe-6.5%Si bands with powder extruding - Google Patents

A kind of method that diffusion-sintering prepares Fe-6.5%Si bands with powder extruding Download PDF

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CN108097967A
CN108097967A CN201711369193.8A CN201711369193A CN108097967A CN 108097967 A CN108097967 A CN 108097967A CN 201711369193 A CN201711369193 A CN 201711369193A CN 108097967 A CN108097967 A CN 108097967A
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powder
sintering
diffusion
extrusion
bands
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CN108097967B (en
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丁艺
罗丰华
周立岩
卢静
吴子恺
贾吉祥
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Central South University
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/20Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces by extruding
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F3/00Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
    • B22F3/10Sintering only
    • B22F3/1003Use of special medium during sintering, e.g. sintering aid
    • B22F3/1007Atmosphere
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C33/00Making ferrous alloys
    • C22C33/02Making ferrous alloys by powder metallurgy
    • C22C33/0257Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
    • C22C33/0278Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
    • CCHEMISTRY; METALLURGY
    • C22METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22CALLOYS
    • C22C38/00Ferrous alloys, e.g. steel alloys
    • C22C38/02Ferrous alloys, e.g. steel alloys containing silicon
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22FWORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F2998/00Supplementary information concerning processes or compositions relating to powder metallurgy
    • B22F2998/10Processes characterised by the sequence of their steps

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacturing & Machinery (AREA)
  • Powder Metallurgy (AREA)

Abstract

A kind of method that diffusion-sintering prepares Fe 6.5%Si bands with powder extruding, chooses reduction Fe powder and water atomization Fe powder, according to 4:6~6:4 ratio mixing, then the HIGH-PURITY SILICON iron powder that Si contents are 50~70% is added, form Fe 4.5~6.7%Si mixed powders.It is molded squarely base; it is heated to 950~1050 DEG C of realization Fe phase austenitizings; slab is hot extruded into the deflection that extrusion ratio is 8~16; vacuum or protection of reducing atmosphere sintering are carried out at 1060~1160 DEG C again; multiple cold rolling, low temperature diffusion sintering, are finally sintered in 1260~1320 DEG C of vacuum or protection of reducing atmosphere, realize the homogeneous alloy of high silicon steel; it is thick to obtain 0.1~0.5mm containing 4.5~6.7%Si, density >=7.41g/cm3High silicon steel band.

Description

A kind of method that diffusion-sintering prepares Fe-6.5%Si bands with powder extruding
Technical field
The present invention principally falls into preparation and the manufacture field of metal material, and in particular to the powder metallurgy of high silicon steel thin belt material The method of sintering, hot extrusion and rolling deformation.
Technical background
Remanent magnetism and coercive force all very littles of soft magnetic material, i.e. hysteresis loop is very narrow, it and fundamental magnetization curve are almost It overlaps, is mainly used for the iron core of inductance coil, transformer, relay and motor.Fe-Si alloys maximum permeability is sent out with Si contents Changing, respectively Si mass percent it is (the same below) for 2% and 6.5% nearby there is the peak of two maximum permeabilities Value, respectively reaches 10000 and 25000.There is no absolute predominances, such as slope in soft magnetic materials for the maximum permeability of Fe-Si alloys The maximum permeability of alloy can not reach 200000.However the manufacture of the Fe-Si lattens of Si < 4.5% is at low cost, therefore Silicon steel sheet is also known as electrical sheet or silicon steel thin slice, is a kind of very important magnetic material.
And Si>When 4.5%, below 540 DEG C of temperature B can occur for Fe-Si alloys2The eutectoid decomposition reaction of ordered phase, it is raw Into the unordered phases of α-Fe and DO3Ordered phase so that alloy becomes fragile and is difficult to deform.
For iron Si system alloy of the Si contents between 4.5~6.7%, commonly referred to as high silicon steel, wherein silicone content 6.5% High silicon steel it is mostly important.Its reason is Fe-Si alloy grains edge<100>The magnetostriction coefficient in direction increases with Si contents And reduce, it disappears substantially at about 6.3%, and<111>The magnetostriction coefficient in direction increases with Si contents and is increased, about When 6.1% with<100>The magnetostriction coefficient in direction is equal so that high silicon steel shows excellent low in higher frequency operation Iron loss characteristic.
The transformer of normal operation can occur continuous uniform " drone " sound, this is because alternating current by transformer around Group when, in the core between generate periodically variable alternating flux, cause iron core magnetostriction and shake the sound sent.Greatly The sound that the iron core of amount or large size is sent in vibrations not only causes the loss of energy, also creates noise pollution.Especially It is in the military aviations such as spacecraft, submarine and guided missile field, Fe-Si systems alloy plays particularly important role.20th century 60 Age Mo, the alloy of Si contents 6.5% are appeared in as transformer material on No. 11 airships of Apollo, are completed the mankind and are landed on the moon for the first time Heroic undertaking.As it can be seen that high silicon steel is the environment-friendly type soft magnetic materials of a kind of consumption reduction of function admirable, noise reduction.
Compared to other alloys, the research and development process of high silicon steel is relatively very long.Late 1920s A.Schulze is for the first time the study found that the iron Si system alloy of silicone content 6.5% has the almost nil characteristic of magnetostriction coefficient. In the 1980s, professor K.I.Arail etc. has found the high silicon steel alloy low compared to traditional Si content in exchange dynamic magnetic field In have lower iron loss and higher magnetic conductivity.Hereafter between many decades, in order to overcome the brittleness of high silicon steel, in technology of preparing side There are many trials in face.As the special rolled method of jacket or temperature control, rapid solidification method, chemical vapour deposition technique (CVD method), Plasma chemical vapor deposition (PCVD methods), hot dipping ooze a diffusion annealing method, powder metallurgic method, microalloying and are modified Etc. various methods.
Wherein CVD is the successful example of comparison.NKK companies of Japan in 1988 have produced thickness for the first time using CVD technology It spends for 0.1~0.5mm, width is the No yield point 6.5%Si steel discs of 400mm.Phase early 1990s, global first commercialization Can realize that the CVD production lines of continuous siliconising are developed, the product size of production can reach 0.1~0.3mm × 600mm。
The principle of CVD is:Under specific temperature conditions, silicon-containing gas (SiCl4) can react generation Fe- with silicon strip Si compounds, and to alloy diffusion inside alloy is finally made to reach required content by raised furnace temperature.Although oneself uses this Technology realizes small-scale industrialized production, but its scale and yield all can not much meet the need in international soft magnetic materials market It asks, and this preparation method technical process is sufficiently complex, energy consumption and of high cost, operating environment and its severe, it is impossible to meet ring Guaranteed request.
High silicon steel is " the steel art work ", and technology of preparing is all always and everywhere state-of-the-art steel and iron manufacturing technology, and It is the hot spot of development and exploitation.For 6.5%Si high silicon steel, excellent magnetic performance and wide application prospect are even more to inhale Draw scientific worker and carry out substantial amounts of research-and-development activity.The development of preparation process and ripe and can be cost-effectively Production is that 6.5%Si high silicon steel move towards to be commercialized widely applied key, also the always emphasis of research work.Once grope Go out simple, economic, effective, ripe preparation process, will just generate huge economic benefit and social benefit.
The content of the invention
The side of Fe-6.5%Si thin strips is prepared with powder extruding the object of the present invention is to provide a kind of sintering of High temperature diffusion Method, the problem of being difficult to shape for the Fe-Si alloy thin band materials of 4.5~6.7%Si contents, using technical pure Fe powder and Si contents as 50~70% HIGH-PURITY SILICON iron powder is raw material, and extruding green compact are molded into after adding binder, then using powder hot-extrusion method system For certain thickness slab is gone out, acted on using the large deformation of hot extrusion and cause the raising of extruded stock density, structure refinement, and in thermal expansion It is partially-alloyed to dissipate the lower realization of effect, forms the α-Fe crystal grain of the poor Si of plastic deformation ability and the multiphase group of the high Si phases of brittleness It knits.Thin plate subsequently is obtained after multi-pass cold rolling-sintering, is finally sintered using High temperature diffusion and obtains the high silicon strip of homogeneous single phase Material.
The present invention is achieved by the following technical solutions:Reduction Fe powder and two kinds of Industrial iron powders of water atomization Fe powder are chosen, According to 4:6~6:4 mass ratio mixing, forms technical pure Fe powder basic materials, then adds fine Si contents as 50~70% HIGH-PURITY SILICON iron powder for raw material, form Fe-4.5~6.7%Si mixed powders.It will be fine by suitable bonding agent, dispersant HIGH-PURITY SILICON iron powder adhered in mixed process in the hole of iron powder surface or filling ferrous powder.Due to technical pure Fe powder be with The big particle of high-compressibility occupies larger volume ratio in mixed powder, its modeling is not significantly reduced after adding HIGH-PURITY SILICON iron powder Property deformability, can be by being molded squarely base.950~1050 DEG C of realization Fe phase austenitizings are heated to, use extrusion ratio Slab is hot extruded into for 8~16 deflection.Then powder is squeezed into slab and carries out vacuum in 1060~1160 DEG C of temperature ranges Or protection of reducing atmosphere sintering, make Fe powder particles realize metallurgical binding, and Si and Fe realize it is partially-alloyed, formed densification, The high silicon steel blank of heterogeneous structure of the high Si phases of α-Fe crystal grain and brittleness with the poor Si of plastic deformation ability.Subsequently through repeatedly cold It rolls, low temperature diffusion sintering, the density rise of slab, plate thickness are reduced, and the alloying level of Si is also continuously improved.Finally 1260 The homogeneous alloy of high silicon steel is realized in vacuum or protection of reducing atmosphere sintering in~1320 DEG C of temperature ranges with the help of thermal diffusion Change, obtain 0.1~0.5mm thickness containing 4.5~6.7%Si, density >=7.41g/cm3High silicon steel band.
The method of the present invention specifically comprises the following steps:
(1) raw material powder prepares
Using -100 mesh reduced iron powders, Fe >=98.5% in Fe powder is reduced, remaining is the impurity such as Si, Mn, P, S, using - 100 mesh water-atomized iron powders, Fe >=99.0% in water atomization Fe powder, remaining is the impurity such as Si, Mn, P, S.It will reduction Fe powder and water mist Change Fe powder according to 4:6~6:4 mass ratio is prepared, and shape is mixed using conical mixer, V-arrangement batch mixer or drum mixer Into technical pure Fe powder basic materials, incorporation time is 2~6h, can be added in mixed process according to 200~500ml/ tons of ratio A small amount of absolute ethyl alcohol.
Using the Si contents of refining, grain size≤6 μm, this ferrosilicon powder is except containing 50 for 50~70% HIGH-PURITY SILICON iron powder Beyond~70%Si, major impurity is~0.24%Al ,~0.07%Ca and~0.02%C, remaining is Fe.
Reduced iron powder is a kind of widely used Industrial iron powder, has irregular porous pattern, micro- beneficial to storing, adhering to Fine silica powder, and in follow-up powder extrusion process also being mutually twisted for powder easy to implement and improve the intensity of green compact, be conducive to The stabilization of powder extrusion process.Water atomization Fe powder is also a kind of widely used Industrial iron powder, has subsphaeroidal pattern, and impurity contains Amount has higher compressibility and mobility, is conducive to the uniform flow of powder extrusion process course powder less than reduction Fe powder Dynamic, low impurity content is favourable to the soft magnetic characteristic of high silicon steel in water atomization Fe powder.It will two kinds of reduction Fe powder and water atomization Fe powder Industrial iron powder, according to 4:6~6:4 ratio mixing, forms technical pure Fe powder basic materials, and it is each to be conducive to two kinds of straight iron powders of performance From advantage, be also relatively common method in industrial production iron-base part.
Fe-50~70%Si high purity ferrosilicons in process of setting there are two eutectic reactions, when rich Si one sides are at 1207 DEG C Form the β-FeSi with tP3 structures2With Si phase eutectic structures, form when rich Fe one sides are at 1212 DEG C and tied with tP3 β-the FeSi of structure2With the FeSi eutectic structures of cP8 structures;At 982 DEG C and 937 DEG C, also there are β-FeSi2Decomposition and oC48- FeSi2Two solid-state phase changes processes of formation of phase.Therefore it is easy in process of setting of the Fe-50~70%Si after refining crisp Change, form subtle Fe-Si or Si heterogeneous structures, it is easy to refine by Mechanical Crushing technique.Fe-50~70%Si is high-purity Ferrosilicon is crushed to≤6 μm of ferrosilicon powder, Si phases, FeSi in actual tissue2, FeSi phases it is more tiny, be conducive to subsequent high temperature The thermal diffusion homogenization of Si elements, forms homogeneous Fe-6.5%Si single-phase alloys during sintering.Meanwhile exist in high purity ferrosilicon powder 30~50%Fe can effectively reduce the degree of oxidation of Si, be conducive to improve the product quality of high silicon steel.
By Fe-50~70%Si high purity ferrosilicons Mechanical Crushing to grain size≤6 μm, be conducive to it and be adhered to the table of reduction Fe powder Face is filled in the hole of reduction Fe powder, tiny Si, FeSi2, FeSi phases Dispersed precipitate in blank, play structure refinement Strengthening and Toughening effect, be conducive to improve subsequent blank toughness, cracking do not easily caused in densification process is rolled.But Fe-50 Still containing a small amount of Si phases in~70%Si high purity ferrosilicons, Si is easily absorbing oxygen, and SiO is formed in exposed Si phase surfaces2Film, Therefore in the preparation, storage and transfer process of Fe-50~70%Si HIGH-PURITY SILICON iron powders and follow-up batch mixing, powder hot extrusion, Inert gas shielding should be used in the operation of rolling, used instrument must also take dehydration, drying process in advance.
On the premise of oxygen content is controlled, influence of the impurity such as other Al, Ca, Mn to alloy magnetic property is little, in the process The possibility for introducing other alloying elements is also little.
(2) powder mixes
According to the ratio of Fe-4.5~6.7%Si, water atomization Fe powder and fine Fe-50~70%Si high purity ferrosilicons are weighed Powder;It is mixed under inert protective atmosphere using low energy mixers such as conical mixer, V-arrangement batch mixer or drum mixers, Mixing velocity and time, processing hardening occurred in mixed process for the mitigation Fe powder that should try one's best depending on mixing uniformity.
(3) powder squeezes
Square green compact is prepared using compression-moulding methods, green density is 6.41~6.60g/cm3;Using square extruding Cylinder, extrusion ratio are 8~16, using sintered-carbide die, lubricant are done with machine oil and glass dust, by molding square billet in nitrogen before squeezing Be heated to 950~1050 DEG C under gas shielded effect, keep the temperature 2~4h, extrusion cylinder and extrusion die 400~600 DEG C of preheating insulations 1~ 2h implements hot extrusion, and the density of slab is 6.86~7.18g/cm after hot extrusion3
(4) it is sintered
Hot extrusion pressing plate is placed on surface to be coated in the support plate of MgO micro mists, is placed into sintering furnace.Using 2~5 DEG C/heating rate of min, it is warming up to 1060~1160 DEG C of 2~4h of heat preservation sintering.Sintered blank density is 7.28~7.40g/cm3。 Compared with extruded stock density, density slightly reduces.
Sintering temperature is too low, is unfavorable for the metallurgical binding of Fe powder particles and Si element thermal diffusions;And sintering temperature is excessively high then Si elements can be caused quickly to spread, cause crystal grain excessive high hardness, embrittlement, follow-up rolling deformation is difficult to realize.
Take reproducibility, inert gas shielding sintering.Can be used during sintering W, Mo, heat resisting steel etc. as support plate (or Burn boat), the ceramic wafers such as corundum, zirconium oxide can also be used, but metallic plate thermal conductivity is good, and beneficial to Even Sintering.
The texture of coarse crystal containing the second phase is formed after sintering.X-ray diffraction Discriminating materials are heterogeneous Fe (Si) Phase, body-centred cubic several characteristic peaks have apparent separating phenomenon, illustrate there are 2 kinds of different Fe phases of Si solid solubility, wherein must Have that the Si contents in a kind of Fe phases are low, there is plastic deformation ability.
(5) cold rolling-sintering densification
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, single pass rolling reduction≤8%, through multi- pass rolling to stagnation pressure After lower rate reaches 30~45%, then in 1060~1160 DEG C of 0.5~2h of heat preservation sintering in sintering furnace.After multiple cold rolling-sintering, The thickness of plate reaches 0.1~0.5mm, and density reaches 7.40~7.51g/cm3
Cold-rolling deformation can be born since there are deformable Fe phases, slab in blank.But there is also more in slab High Si phases, performance is more crisp, therefore for amount not above 8%, accumulation total reduction reaches 30~45%, about needs under every time rolling Want 8~20 passages.
Due to existing hard crisp phase, it is necessary to take and keep the temperature vacuum-sintering or restitutive protection's gas again at 1060~1160 DEG C Atmosphere is sintered, to realize that the closing of pores and the reparation of crackle and a degree of Si elements homogenization are generated in cold-rolled process expands It dissipates., it is necessary to be sintered 1 time again, from the hot extrusion of 2.5~5.0mm after sintered accumulation drafts reaches 30~45% every time Plate is rolled down to 0.1~0.5mm, takes around and is sintered 6~10 times again.
(6) high temperature sintering is homogenized
Vacuum or restitutive protection 1~4h of atmosphere sintering in 1260~1320 DEG C of temperature ranges, in the effect of thermal diffusion Under, it realizes the homogenization of Si, forms single-phase alloy, obtain the high silicon steel of homogeneous.The thickness of plate is almost unchanged after densification sintering, For 0.1~0.5mm, density slightly reduces, and reaches 7.42~7.46g/cm3
In step (1) mixed process absolute ethyl alcohol is added in 200~500ml/ tons of ratio.
The ferrosilicon powder of grain size≤6 μm is by high-energy ball milling or rushes the acquisition of rotation method.
Step (2) adds cellulose, paraffin micro mist or the water-insoluble binder of zinc stearate, the additive amount of binder when mixing Total amount is no more than the 0.8% of mixed-powder gross mass, while adds grease and absolute ethyl alcohol does passivator, plays the high Si iron of passivation Powder, bonding Fe-Si powder, the effect for enhancing powder flowbility and compact strength, the additive amount total amount of passivator are no more than mixed powder The 2% of last gross mass.
Using the square extrusion cylinder of 40 × 120mm in step (3), extrusion die is 5~2.5mm × 120mm, corresponding extrusion ratio Respectively 8~16;Using sintered-carbide die, lubricant is done with machine oil and glass dust, implements hot extrusion using 300 tons of press, Three point bending test shows plasticity, 178~340MPa.
Support plate described in step (4) uses corundum or zirconia ceramics plate.
During high temperature sintering described in step (6), overlapping places sintering plate, and interlayer is laid with MgO powder, and plate tiling is placed, Tablet weight is placed on plate, prevents from deforming in sintering process.
In addition to Si contents, content of elements such as grain size, crystal grain orientation, C etc. also has the magnetic behavior of high silicon steel Large effect can subsequently be annealed by wet hydrogen, the technological means such as normalizing treatment are controlled by.
Essence of the invention is by being with the addition of granularity≤6 in the technical pure Fe powder of the big volumetric portion with good plasticity μm Fe-50~70%Si high-purity powders, formed Fe-4.5~6.7%Si mixed powders.High density, height are obtained using hot extrusion Uniformity slab.The element alloyed degree of slab Si is low, microscopic structure by high-ductility Fe phases and brittleness richness Si phase compositions, With high cold deformation ability, can structural homogenity and compactness be improved by multi-pass cold rolling and sintering, then High temperature diffusion is burnt Knot realizes the homogenization of Si, so as to obtain the high silicon steel band of high quality.This method realizes work by technique and equipment Design Skill process automation, continuous production, can be mass-produced 0.1~0.5mm thickness, density >=7.41g/cm3High silicon steel band.
Description of the drawings
Fig. 1 is the three-point bending graph of blank after the powder of the embodiment of the present invention 1 squeezes;
Fig. 2 is metallographic structure figure after powder extruding-cold rolling-sintering of the embodiment of the present invention 2;
Fig. 3 is XRD diffraction curve figures after powder extruding-cold rolling-sintering of the embodiment of the present invention 2;
Fig. 4 is XRD diffraction curve figures after powder extruding-cold rolling-high temperature sintering of the embodiment of the present invention 4.
Specific embodiment
The present invention is described in further detail with reference to the accompanying drawings and detailed description.
Embodiment 1
By the water atomization Fe powder of the reduction Fe powder of -100 mesh and -100 mesh according to 4:6 ratio is prepared, and is mixed using drum-type Material machine is mixed to form technical pure Fe powder raw materials, incorporation time 2h, is added in mixed process according to 200ml/ tons of ratio anhydrous Ethyl alcohol.
By well pre-mixed technical pure Fe powder and the Fe-70%Si high-purity powders of granularity≤6 μm according to 90.43:9.57 Ratio mixes, and forms the mixed-powder of Fe-6.7%Si.The paraffin micro mist of raw material total amount 0.6%, 0.1% machine are added during mixing Oil.Absolute ethyl alcohol is added according to 200ml/ tons of amount.Using V-arrangement batch mixer by above-mentioned powder mixing 4h.
Square green compact is prepared using compression-moulding methods, the length and width of green compact is respectively 120mm and 80mm, is highly 40mm uses surface pressing to be suppressed for the pressure of 600MPa, and the total output pressure of press is 576 tons.The green density of acquisition is 6.41g/cm3
Using the square extrusion cylinder of 40 × 120mm, extrusion die is respectively 5 × 120mm, and corresponding extrusion ratio is 8.It will before squeezing Molding square billet is heated to 950 DEG C under nitrogen protective effect, keeps the temperature 4h.Extrusion cylinder and extrusion die are in 600 DEG C of preheating insulation 2h.It adopts Implement hot extrusion with 300 tons of press, the density of slab is 6.86g/cm after hot extrusion3, three point bending test shows plasticity, sees Fig. 1, bending strength 178MPa.
Using the heating rate of 2 DEG C/min, 1060 DEG C of heat preservation sintering 2h are warming up to.Sintered blank density is 7.28g/cm3.It burns The texture of coarse crystal containing the second phase is formed after knot.
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, single pass rolling reduction≤8%, through multi- pass rolling to stagnation pressure After lower rate reaches 30~45%, then in 1060 DEG C of heat preservation sintering 2h in sintering furnace.Specifically pressure-annealing schedule is:5mm→ 3.5mm → 2.4mm → 1.6mm → 1.02mm → 0.71mm → 0.49mm, i.e., after 6 cold rollings and 5 sintering, the thickness of plate Reach 0.49mm, density reaches 7.40g/cm3
1h finally is sintered in 1320 DEG C of Temperature Vacuums, under the action of thermal diffusion, the homogenization of Si is realized, forms single-phase conjunction Gold obtains the high silicon steel of homogeneous.The thickness of plate is almost unchanged after densification sintering, is 0.49mm, and density reaches 7.41g/cm3
Embodiment 2
By the water atomization Fe powder of the reduction Fe powder of -100 mesh and -100 mesh according to 5:6 ratio is prepared, and is mixed using drum-type Material machine is mixed to form technical pure Fe powder raw materials, incorporation time 3h, is added in mixed process according to 400ml/ tons of ratio anhydrous Ethyl alcohol.
By well pre-mixed technical pure Fe powder and the Fe-50%Si high-purity powders of granularity≤10 μm according to 91:9 ratio is mixed It closes, forms the mixed-powder of Fe-4.5%Si.The zinc stearate of raw material total amount 0.7%, 0.1% machine oil are added during mixing.Nothing Water-ethanol is added according to 400ml/ tons of amount.Using drum mixer by above-mentioned powder mixing 6h.
Square green compact is prepared using compression-moulding methods, the length and width of green compact is respectively 120mm and 80mm, is highly 40mm uses surface pressing to be suppressed for the pressure of 600MPa, and the total output pressure of press is 576 tons.The green density of acquisition is 6.60g/cm3
Using the square extrusion cylinder of 40 × 120mm, extrusion die is 2.5 × 120mm, and corresponding extrusion ratio is 16.It will before squeezing Molding square billet is heated to 1050 DEG C under nitrogen protective effect, keeps the temperature 2h.Extrusion cylinder and extrusion die are in 600 DEG C of preheating insulation 2h. Implement hot extrusion using 300 tons of press, the density of slab is 7.18g/cm after hot extrusion3, three point bending test shows plasticity, Bending strength is 340MPa.
Using the heating rate of 2 DEG C/min, 1160 DEG C of heat preservation sintering 2h are warming up to.Sintered blank density is 7.40g/cm3.It burns The texture of coarse crystal containing the second phase is formed after knot, sees Fig. 2.X-ray diffraction Discriminating materials are heterogeneous Fe (Si) phase, such as Fig. 3 findings, body-centred cubic several characteristic peaks have apparent separating phenomenon, illustrate there are 2 kinds of different Fe phases of Si solid solubility, In must have that the Si contents in a kind of Fe phases are low, there is plastic deformation ability.
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, single pass rolling reduction≤8%, through multi- pass rolling to stagnation pressure After lower rate reaches 30~45%, then in 1160 DEG C of heat preservation sintering 0.5h in sintering furnace.After multiple cold rolling-sintering, the thickness of plate Degree reaches 0.1mm, and density reaches 7.43g/cm3.Specifically cold rolling-sintering schedule is:2.5mm→1.85mm→1.39mm→ 1.15mm → 0.89mm → 0.65mm → 0.39mm → 0.25mm → 0.17mm → 0.13mm → 0.10mm, i.e., through 10 cold rollings and After 9 sintering, the thickness of plate reaches 0.10mm, and density reaches 7.51g/cm3
4h finally is sintered in 1260 DEG C of Temperature Vacuums, forms the high silicon steel of single-phase homogeneous that Si contents are 4.5%, thickness is 0.1mm, density reach 7.52g/cm3
Embodiment 3
By the water atomization Fe powder of the reduction Fe powder of -100 mesh and -100 mesh according to 6:4 ratio is prepared, and is mixed using drum-type Material machine is mixed to form technical pure Fe powder raw materials, incorporation time 4h, is added in mixed process according to 500ml/ tons of ratio anhydrous Ethyl alcohol.
By well pre-mixed technical pure Fe powder and the Fe-60%Si high-purity powders of granularity≤6 μm according to 89.17:10.83 Ratio mixes, and forms the mixed-powder of Fe-6.5%Si.The paraffin micro mist of raw material total amount 0.4%, 0.2% first are added during mixing Base cellulose, 0.1% machine oil.Absolute ethyl alcohol is added according to 400ml/ tons of amount.Using drum mixer by above-mentioned powder Mix 6h.
Square green compact is prepared using compression-moulding methods, the length and width of green compact is respectively 120mm and 80mm, is highly 40mm uses surface pressing to be suppressed for the pressure of 600MPa, and the total output pressure of press is 576 tons.The green density of acquisition is 6.44g/cm3
Using the square extrusion cylinder of 40 × 120mm, extrusion die is 4 × 120mm, and corresponding extrusion ratio is 10.By mould before squeezing Pressure square billet is heated to 1000 DEG C under nitrogen protective effect, keeps the temperature 3h.Extrusion cylinder and extrusion die are in 600 DEG C of preheating insulation 2h.It adopts Implement hot extrusion with 300 tons of press, the density of slab is 6.89g/cm after hot extrusion3, bending strength 210MPa.
Using the heating rate of 3 DEG C/min, 1150 DEG C of heat preservation sintering 2h are warming up to.Sintered blank density is 7.30g/cm3
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, and specific cold rolling-sintering schedule is:4.0mm→2.8mm→ 2.0mm → 1.40mm → 1.08mm → 0.70mm → 0.45mm → 0.27mm, i.e., after 7 cold rollings and 6 sintering, the thickness of plate Degree reaches 0.27mm, and density reaches 7.41g/cm3
For above-mentioned cold rolling made-up belt in 1280 DEG C of vacuum-sintering 2h, it is about 0.27mm, density 7.42g/cm to obtain thickness3, Si Content is the 6.5% high silicon steel of single-phase homogeneous.
Embodiment 4
By the water atomization Fe powder of the reduction Fe powder of -100 mesh and -100 mesh according to 5:5 ratio is prepared, and is mixed using drum-type Material machine is mixed to form technical pure Fe powder raw materials, incorporation time 6h, is added in mixed process according to 500ml/ tons of ratio anhydrous Ethyl alcohol.
By well pre-mixed technical pure Fe powder and the Fe-62%Si high-purity powders of granularity≤10 μm according to 90.64:9.36 Ratio mixes, and forms the mixed-powder of Fe-5.8%Si.The paraffin micro mist of raw material total amount 0.6%, 0.2% machine are added during mixing Oil.Absolute ethyl alcohol is added according to 400ml/ tons of amount.Using drum mixer by above-mentioned powder mixing 3h.
Square green compact is prepared using compression-moulding methods, the length and width of green compact is respectively 120mm and 80mm, is highly 40mm uses surface pressing to be suppressed for the pressure of 600MPa, and the total output pressure of press is 576 tons.The green density of acquisition is 6.46g/cm3
Using the square extrusion cylinder of 40 × 120mm, extrusion die is respectively 3.2 × 120mm, and corresponding extrusion ratio is 12.5.It squeezes Molding square billet under nitrogen protective effect is heated to 1020 DEG C before pressure, keeps the temperature 4h.Extrusion cylinder and extrusion die are protected in 600 DEG C of preheatings Warm 2h.Implement hot extrusion using 300 tons of press, the density of slab is 6.90g/cm after hot extrusion3, bending strength 223MPa.
Using the heating rate of 4 DEG C/min, 1120 DEG C of heat preservation sintering 2h are warming up to.Sintered blank density is 7.29g/cm3
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, single pass rolling reduction≤8%, through multi- pass rolling to stagnation pressure After lower rate reaches 30~45%, then in 1120 DEG C of heat preservation sintering 1h in sintering furnace.After multiple cold rolling-sintering, the thickness of plate Reach 0.22mm, density reaches 7.43g/cm3.Specifically cold rolling-sintering schedule is:3.2mm→2.4mm→2.0mm→1.3mm→ 0.96mm → 0.72mm → 0.46mm → 0.32mm → 0.21mm, i.e., after 9 cold rollings and 8 sintering, the thickness of plate reaches 0.21mm, density reach 7.42g/cm3
For above-mentioned cold rolling made-up belt in 1300 DEG C of vacuum-sintering 2h, it is about 0.22mm, density 7.43g/cm to obtain thickness3, Si Content is 5.8%, and the XRD analysis figure of final plate is shown in Fig. 3, is the high silicon steel of single-phase homogeneous.

Claims (7)

1. a kind of method that diffusion-sintering prepares Fe-6.5%Si bands with powder extruding, it is characterised in that comprise the following steps:
(1) raw material powder prepares
Using -100 mesh reduced iron powders, Fe >=98.5% in Fe powder is reduced, remaining is Si, Mn, P, S and other are inevitably miscellaneous Matter, using -100 mesh water-atomized iron powders, Fe >=99.0% in water atomization Fe powder, remaining is Si, Mn, P, S and other are inevitable Impurity, will reduction Fe powder and water atomization Fe powder according to 4:6~6:4 mass ratio is prepared, using conical mixer, V-arrangement batch mixing Machine or drum mixer are mixed to form technical pure Fe powder basic materials, and incorporation time is 2~6h;
The Si contents of refining are used as 50~70% HIGH-PURITY SILICON iron powder, grain size≤6 μm, the major impurity of HIGH-PURITY SILICON iron powder for~ 0.24%Al ,~0.07%Ca and~0.02%C, remaining is Fe;
(2) powder mixes
According to the ratio of Fe-4.5~6.7%Si, water atomization Fe powder and fine Fe-50~70%Si HIGH-PURITY SILICONs iron powder are weighed; Using conical mixer, V-arrangement batch mixer or drum mixer mixing under inert protective atmosphere;
(3) powder squeezes
Square green compact is prepared using compression-moulding methods, green density is 6.41~6.60g/cm3;Using square extrusion cylinder, squeeze Pressure ratio is 8~16, and using sintered-carbide die, lubricant is done with machine oil and glass dust, protects molding square billet in nitrogen before squeezing 950~1050 DEG C are heated under shield effect, keep the temperature 2~4h, extrusion cylinder and extrusion die in 400~600 DEG C of 1~2h of preheating insulation, Implement hot extrusion, the density of slab is 6.86~7.18g/cm after hot extrusion3
(4) it is sintered
Hot extrusion pressing plate is placed on surface to be coated in the support plate of MgO micro mists, is placed into sintering furnace, using 2~5 DEG C/min Heating rate, be warming up to 1060~1160 DEG C of 2~4h of heat preservation sintering, sintered blank density is 7.28~7.40g/cm3
(5) cold rolling-sintering densification:
By above-mentioned sintering slab, progressively cold rolling-sintering is thinned, single pass rolling reduction≤8%, through multi- pass rolling to total reduction After reaching 30~45%, then in 1060~1160 DEG C of 0.5~2h of heat preservation sintering, after multiple cold rolling-sintering, plate in sintering furnace Thickness reach 0.1~0.5mm, density reaches 7.40~7.51g/cm3
(6) high temperature sintering is homogenized:
Vacuum or restitutive protection 1~4h of atmosphere sintering in 1260~1320 DEG C of temperature ranges, it is real under the action of thermal diffusion The homogenization of existing Si forms single-phase alloy, obtains the high silicon steel of homogeneous, and the thickness of plate is 0.1~0.5mm after densification sintering, Density reaches 7.41~7.52g/cm3
2. the method that diffusion-sintering as described in claim 1 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: In step (1) mixed process absolute ethyl alcohol is added in 200~500ml/ tons of ratio.
3. the method that diffusion-sintering as claimed in claim 2 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: The HIGH-PURITY SILICON iron powder of grain size≤6 μm is by high-energy ball milling or rushes the acquisition of rotation method.
4. the method that diffusion-sintering as claimed in claim 2 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: Step (2) adds cellulose, paraffin micro mist or the water-insoluble binder of zinc stearate when mixing, and the additive amount total amount of binder does not surpass The 0.8% of mixed-powder gross mass is crossed, while adds grease and absolute ethyl alcohol does passivator, plays the high Si iron powders of passivation, bonding Fe- The effect of Si powder, enhancing powder flowbility and compact strength, the additive amount total amount of passivator are no more than mixed-powder gross mass 2%.
5. the method that diffusion-sintering as described in claim 1 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: Using the square extrusion cylinder of 40 × 120mm in step (3), extrusion die is 5~2.5mm × 120mm, and corresponding extrusion ratio is respectively 8 ~16;Using sintered-carbide die, lubricant is done with machine oil and glass dust, implements hot extrusion, three-point bending using 300 tons of press Experiment shows plasticity, and bending strength is 178~340MPa.
6. the method that diffusion-sintering as described in claim 1 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: Support plate described in step (4) uses molybdenum plate, W plates, heat resisting steel, corundum or zirconia ceramics plate.
7. the method that diffusion-sintering as described in claim 1 prepares Fe-6.5%Si bands with powder extruding, it is characterised in that: During high temperature sintering described in step (6), overlapping places sintering plate, and interlayer is laid with MgO powder, and plate tiling is placed, on plate Tablet weight is placed, prevents from deforming in sintering process.
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