CN108044095A

CN108044095A - A kind of method that diffusion-sintering prepares Fe-6.5%Si bands with powder rolling

Info

Publication number: CN108044095A
Application number: CN201711368364.5A
Authority: CN
Inventors: 罗丰华; 牟楠; 李益民; 贾吉祥; 吴博天
Original assignee: Central South University
Current assignee: Central South University
Priority date: 2017-12-18
Filing date: 2017-12-18
Publication date: 2018-05-18

Abstract

A kind of method that diffusion-sintering prepares Fe 6.5%Si bands with powder rolling, the present invention 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.Porous slab is formed by powder rolling; vacuum or protection of reducing atmosphere sintering are carried out at 1050~1150 DEG C again; Fe powder particles is made to realize not exclusively connection; and Si and Fe realizes partially-alloyed, the high silicon steel blank of porous, with compressibility the incomplete alloying of formation, through multiple cold rolling, not exclusively sintering; finally in 1260~1340 DEG C of sintering; it realizes the homogeneous alloy of high silicon steel, obtains 0.1~0.5mm thickness containing 4.5~6.7%Si, 7.34~7.50g/cm of density³High silicon steel band.

Description

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

Technical field

Preparation and manufacture field the invention belongs to metal material, and in particular to the powder of the high silicon steel soft magnetism band of high-performance Metallurgy sintered and rolling deformation method.

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 rolling 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, is formed with compressibility powder mixture after adding binder, then is rolled using powder Method processed prepares certain thickness slab, degreasing, sintering after form porous, heterogeneous blank, by multi-pass cold rolling- Thin plate is obtained after sintering, is finally sintered using High temperature diffusion and obtains the high silicon steel band of homogeneous.

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 ratio mixing, forms technical pure Fe powder basic materials, then it is 50~70% to add fine Si contents HIGH-PURITY SILICON iron powder forms Fe-4.5~6.7%Si mixed powders.It will in mixed process by suitable bonding agent, dispersant Fine HIGH-PURITY SILICON iron powder is adhered in the hole of iron powder surface or filling ferrous powder.Since technical pure Fe powder is with high-compressibility Big particle, larger volume ratio is occupied in mixed powder, add fine Si contents be 50~70% HIGH-PURITY SILICON iron powder After will not significantly reduce its deformability, porous slab can be formed by powder rolling.By powder rolling slab 1050~ 1150 DEG C of temperature ranges carry out vacuum or protection of reducing atmosphere sintering, and Fe powder particles is made to realize not exclusively connection, and Si and Fe is real It is existing partially-alloyed, form the high silicon steel blank of incomplete alloying porous, that there is compressibility.Subsequently through repeatedly cold It rolls, be not exclusively sintered, 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 1340 DEG C of temperature ranges with the help of thermal diffusion Change, obtain 0.1~0.5mm thickness containing 4.5~6.7%Si, 7.34~7.50g/cm of density³High silicon steel band.

The method 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 Si, Mn, P, S and other are inevitable Impurity, using -100 mesh water-atomized iron powders, Fe >=99.0% in water atomization Fe powder, remaining for Si, Mn, P, S and other can not The impurity avoided, by reduction Fe powder and water atomization Fe powder according to 4:6~6:4 ratio is prepared, and is mixed using conical mixer, V-arrangement Material machine or drum mixer are mixed to form technical pure Fe powder basic materials, and incorporation time is 2~6h；

Using Si contents, grain size≤6 μm, this ferrosilicon powder is except containing 50~70% for 50~70% HIGH-PURITY SILICON iron powder Beyond 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 during follow-up powder rolling also being mutually twisted for powder easy to implement and improve the intensity of green compact, be conducive to The stabilization of powder rolling 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 rolling 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 in follow-up batch mixing, the operation of rolling Inert gas shielding should be used, used instrument must also take dehydration, drying process in advance.

On the premise of oxygen content is controlled, influence of the impurity such as Al, Ca, Mn to alloy magnetic property is little, introduces in the process The possibility of other alloying elements is also little.

(2) powder mixes

According to the ratio of Fe-4.5~6.7%Si, pre- mixed Fe powder and Fe-50~70%Si HIGH-PURITY SILICON iron powders are weighed； It is mixed under inert protective atmosphere using low energy mixer；

(3) powder rolling

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, Thickness is rolled out as 1.0~2.2mm, width is 100~240mm, and density is 6.15~6.76g/cm³Powder strip plate.

Go out the difference in roller direction by band, powder rolling can be divided into vertical, horizontal and tilt 3 kinds of forms, and feeding manner has Dead weight feeding, forced feed, pre-glued feeding etc..The width of blank is related with the width of feeding trough, and the length of blank regards production Depending on condition is permitted and is actually needed.

(4) degreasing, sintering

Powder strip plate is placed on surface to be coated in the support plate of MgO micro mists, is placed into vacuum degreasing, sintering furnace, 2h~4h is kept the temperature respectively using the heating rate of 2~5 DEG C/min, and in 200 DEG C, 400 DEG C, then will heat up to 1050~1150 DEG C 2~4h of heat preservation sintering, sintered blank density are 6.20~6.82g/cm³。

Uniform equiaxed grain structure is formed after sintering.Matrix grain is about 70~100 μm, and crystal boundary has hole about~10 μm Gap, subsequent rolling and sintering can be closed.Only a small amount of the second phase about~2 μm is remained in matrix, with matrix Tissue has good interface cohesion, i.e., the face divided does not occur.These obvious second phases are certain richness Si phases, these richness Si phases Presence, reduce the Si contents of matrix so that matrix has high plastic deformation ability；Meanwhile with matrix Highly organized interface cohesion and Dispersed precipitate are conducive to subsequently homogenization diffusion.

Sintering temperature is too low, the connection being unfavorable between Fe powder particles and Si atoms permeatings, and sintering temperature is excessively high then can be by In the diffusion into the surface of Fe, Si element, there is coarse hole, be subsequently difficult to press, rolling densification is difficult to realize.

During sintering can powder rolling blank can be placed with multilayer, but must separate between layers, to avoid plate during sintering Base contraction causes to crack.Heating rate should not be too fast during sintering, and multistage heat preservation can be set in temperature-rise period, to realize degassing, take off The effect of fat.Reproducibility or inert gas shielding degreasing, sintering can also be taken.W, Mo, heat resisting steel etc. may be employed during sintering As support plate (or burn boat), the ceramic wafers such as corundum, zirconium oxide can also be used, but metallic plate thermal conductivity it is good and beneficial to uniformly Sintering shrinkage.

(5) cold rolling-sintering densification

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8% reaches 30 through multi- pass rolling to total reduction After~45%, in sintering furnace, 0.5~2h is re-sintered in 1050~1150 DEG C, after multiple cold rolling-sintering, the thickness of plate reaches To 0.1~0.5mm, density reaches 7.33~7.49g/cm³。

Since powder batch is porous organization, and there are deformable Fe phases, slab can bear cold-rolling deformation.Palette There is also more high Si phases in base, performance is more crisp, therefore not above 8%, accumulation total reduction reaches amount under every time rolling 8~20 passages are taken around to 30~45%.

Due to there are a large amount of holes and hard crisp phase, taking when re-sintering for 1050 DEG C~1150 DEG C, in vacuum-sintering or also It is sintered in originality protective atmosphere, realizes the closing of pores and the reparation of crackle and the homogenization diffusion of a degree of Si elements.This When heating rate can be very fast, in 5~10 DEG C/min, can continuous warming, soaking time determines depending on thickness of slab, during thickness of slab >=1mm, protects The warm time is 1~2h；Thickness of slab is reduced to 0.5~1h in 0.1~1mm, soaking time.Sintered accumulation drafts reaches every time , it is necessary to be sintered 1 time again after 30~45%, 0.1~0.5mm is rolled down to from the powder base of 1.0~2.2mm, takes around and burns again Knot 4~8 times.In addition, in order to which the density of plate is made to reach 7.2g/cm³More than (about the 95% of theoretical density), it is also desirable to 4 times Above re-sinters.

By 2 cold rollings-sintered metallographic structure.Matrix is about 100 μm of grain structure, there is a small amount of tiny hole Gap.Matrix grain is there are two types of different contrasts, this is because Si contents are different and cause to corrode difference, low Si is brilliant in this kind tissue Grain is conducive to machining deformation so that the thin plate of 0.1~0.5mm of manufacture is possibly realized.

(6) high temperature sintering is homogenized

Vacuum or restitutive protection 1~4h of atmosphere sintering in 1260~1340 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 7.34~7.50g/cm³。

The absolute ethyl alcohol of 200~500ml is added in step (1) mixed process according to mixed-powder per ton.

With high-energy ball milling or rush rotation method obtain grain size≤6 μm HIGH-PURITY SILICON iron powder.

Low energy mixer described in step (2) is conical mixer, V-arrangement batch mixer or drum mixer.

Step (2) adds that cellulose, paraffin micro mist or zinc stearate are water-insoluble as binder, and binder adds when mixing Dosage total amount is no more than the 0.8% of mixed-powder gross mass, while adds grease and absolute ethyl alcohol does passivator, plays passivation Si 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.

Step (5) is sintered when re-sintering for 1050~1150 DEG C under vacuum-sintering or restitutive protection's atmosphere, by 5~ 10 DEG C/min continuous warmings, during thickness of slab >=1mm, soaking time is 1~2h；Thickness of slab is reduced to 0.5 in 0.1~1mm, soaking time ~1h after sintered accumulation drafts reaches 30~45% every time, is sintered 1 time, is rolled from the powder base of 1.0~2.4mm again To 0.1~0.5mm, it is necessary to be sintered 4~8 times again.

7. the method that High temperature diffusion sintering as described in claim 1 prepares high silicon steel band with powder rolling, feature It is：Overlapping places sintering plate during high temperature sintering, and interlayer is laid with MgO powder.

Support plate described in step (4) burns boat using W, Mo, corundum or zirconia ceramics.

Placement sintering plate can be overlapped during high temperature sintering, but interlayer must be laid with MgO powder, and W, Mo can be used and ceramics are burnt Boat.But plate must tile placement, and tablet weight can be 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, form Fe-4.5~6.7%Si alloy mixtures, powder rolling is laggard into slab Row incomplete alloying sintering makes Fe powder particles realize not exclusively sintering, and Si and Fe realizes partially-alloyed, formation is porous, The high silicon steel blank of incomplete alloying with compressibility.Subsequently through multi-pass cold rolling and sintering, even tissue is improved Property and compactness, then by high-temperature diffusion process, the homogenization of Si is realized, so as to obtain the single-phase high silicon strip of complete alloying Material.This method realizes Technics Process Automation, continuous production by technique and equipment Design, it can be mass-produced 0.1~ 0.5mm is thick, 7.34~7.50g/cm of density³High silicon steel band.

Description of the drawings

Fig. 1 is the sintered metallograph of powder rolling base of the embodiment of the present invention 2；

Fig. 2 is that the plate of the embodiment of the present invention 3 passes through 2 cold rollings-sintered metallograph；

Fig. 3 is XRD diffraction curves after the powder rolling base 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.

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, The powder rolling slab of 2.2mm is rolled out, the width of slab is 100mm.The density of green compact is 6.15g/cm³。

Powder strip plate is placed on surface to be coated on the molybdenum plate of MgO micro mists, is placed into vacuum degreasing, sintering furnace.It adopts With the heating rate of 2 DEG C/min, and 4h is kept the temperature respectively in 200 DEG C, 400 DEG C.Then will heat up to 1050 DEG C of heat preservation sintering 4h.It burns It is 6.2g/cm to tie base density³。

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8% reaches 30 through multi- pass rolling to total reduction After~45%, then in vacuum sintering furnace, in 1050 DEG C of heat preservation sinterings.With 5 DEG C/min speed continuous warmings, soaking time regards plate Thickness determines, during thickness of slab >=1mm, soaking time 2h；Thickness of slab is in 0.1~1mm, soaking time 1h.Specific pressure-annealing schedule For：2.5mm → 1.6mm → 1.02mm → 0.71mm → 0.49mm, i.e., after 4 cold rollings and 3 sintering, the thickness of plate reaches 0.49mm, density reach 7.33g/cm³。

For above-mentioned cold rolling made-up belt in 1340 DEG C of vacuum-sintering 1h, it is about 0.50mm, density 7.34g/cm to obtain thickness³, Si Content is the 6.7% high silicon steel of single-phase homogeneous.

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.

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, The powder rolling slab of 1.0mm is rolled out, the width of slab is 240mm.The density of green compact is 6.76g/cm³。

Powder strip plate is placed on surface to be coated on the molybdenum plate of MgO micro mists, is placed into vacuum degreasing, sintering furnace.It adopts With the heating rate of 5 DEG C/min, and 2h is kept the temperature respectively in 200 DEG C, 400 DEG C.Then will heat up to 1150 DEG C of heat preservation sintering 2h.It burns It is 6.82g/cm to tie base density³。

Uniform equiaxed grain structure is formed after sintering, sees Fig. 1.Matrix grain is about 70~100 μm, and crystal boundary exists about~10 μm hole, it is subsequent rolling and sintering can be closed.Only a small amount of the second phase about~2 μm is remained in matrix, There is good interface cohesion with matrix, i.e., the face divided do not occur.These obvious second phases are certain richness Si phases, these The presence of rich Si phases reduces the Si contents of matrix so that matrix has high plastic deformation ability；Meanwhile Interface cohesion good with matrix and Dispersed precipitate are conducive to subsequently homogenization diffusion.

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8% reaches 30 through multi- pass rolling to total reduction After~45%, then in vacuum sintering furnace, in 1150 DEG C of heat preservation sinterings.With 10 DEG C/min speed continuous warmings, soaking time is 1h.Specifically pressure-annealing schedule is：1.0mm → 0.65mm → 0.39mm → 0.25mm → 0.17mm → 0.13mm → 0.10mm, I.e. after 6 cold rollings and 5 sintering, the thickness of plate reaches 0.10mm, and density reaches 7.49g/cm³。

For above-mentioned cold rolling made-up belt in 1260 DEG C of vacuum-sintering 4h, it is about 0.10mm, density 7.50g/cm to obtain thickness³, Si Content is the 4.5% high silicon steel of single-phase homogeneous.

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.

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, The powder rolling slab of 1.6mm is rolled out, the width of slab is 200mm.The density of green compact is 6.22g/cm³。

Powder strip plate is placed on surface to be coated on the corundum plate of MgO micro mists, the degreasing of hydrogen tube furnace is placed into, burns Knot.Using the heating rate of 3 DEG C/min, and 2h, 400 DEG C of heat preservation 3h are kept the temperature at 200 DEG C.Then it will heat up to 1120 DEG C of heat preservations and burn Tie 3h.Sintered blank density is 6.26g/cm³。

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8% reaches 30 through multi- pass rolling to total reduction After~45%, then in hydrogen tube furnace, in 1120 DEG C of heat preservation sintering 1h.With 6 DEG C/min speed continuous warmings.Specific pressure- Annealing schedule is：1.6mm → 1.08mm → 0.70mm → 0.45mm → 0.27mm, i.e., after 4 cold rollings and 3 sintering, plate Thickness reach 0.27mm, density reaches 7.37g/cm³。

See Fig. 2 by 2 cold rollings-sintered metallographic structure, matrix is about 100 μm of grain structure, is existed a small amount of thin Small hole.Matrix grain is there are two types of different contrasts, this is because Si contents are different and cause to corrode difference, in this kind tissue Low Si crystal grain is conducive to machining deformation so that the thin plate of 0.1~0.5mm of manufacture is possibly realized.

For above-mentioned cold rolling made-up belt in 1320 DEG C of vacuum-sintering 2h, it is about 0.27mm, density 7.38g/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.

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, The powder rolling slab of 2.0mm is rolled out, the width of slab is 180mm.The density of green compact is 6.42g/cm³。

Powder strip plate is placed on surface to be coated on the corundum plate of MgO micro mists, the degreasing of hydrogen tube furnace is placed into, burns Knot.Using the heating rate of 4 DEG C/min, and 3h, 400 DEG C of heat preservation 2h are kept the temperature at 200 DEG C.Then it will heat up to 1130 DEG C of heat preservations and burn Tie 2h.Sintered blank density is 6.46g/cm³。

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8% reaches 30 through multi- pass rolling to total reduction After~45%, then in hydrogen tube furnace, in 1130 DEG C of heat preservation sintering 0.5h.With 8 DEG C/min speed continuous warmings.Specific pressure Under-annealing schedule is：2.0mm → 1.3mm → 0.96mm → 0.72mm → 0.46mm → 0.32mm → 0.21mm is that is, cold through 7 times It rolls with after 6 sintering, the thickness of plate reaches 0.21mm, and density reaches 7.39g/cm³。

For above-mentioned cold rolling made-up belt in 1300 DEG C of vacuum-sintering 2h, it is about 0.22mm, density 7.40g/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

1. a kind of method that High temperature diffusion sintering prepares Fe-6.5%Si thin strips with powder rolling, it is characterised in that including following Step：

(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 ratio is prepared, using conical mixer, V-arrangement batch mixer Or drum mixer is mixed to form technical pure Fe powder basic materials, incorporation time is 2~6h；

Si contents are used as 50~70% HIGH-PURITY SILICON iron powder, grain size≤6 μm, major impurity is~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, pre- mixed Fe powder and Fe-50~70%Si HIGH-PURITY SILICON iron powders are weighed；Lazy Property protective atmosphere under using low energy mixer mix；

(3) powder rolling

Using two roller horizontal mills and feeding trough is tilted, is conducted oneself with dignity using powder, the frictional force feeding between roll and powder, rolled Go out thickness for 1.0~2.2mm, width is 100~240mm, and density is 6.15~6.76g/cm³Powder strip plate；

(4) degreasing, sintering

Powder strip plate is placed on surface to be coated in the support plate of MgO micro mists, is placed into vacuum degreasing, sintering furnace, using 2 The heating rate of~5 DEG C/min, and 2~4h is kept the temperature respectively in 200 DEG C, 400 DEG C, it then will heat up to 1050~1150 DEG C of heat preservations 2~4h is sintered, sintered blank density is 6.2~6.82g/cm³；

(5) cold rolling-sintering densification

By above-mentioned sintering slab rolled thickness reduction, single pass rolling reduction≤8%, reach 30 through multi- pass rolling to total reduction~ After 45%, in sintering furnace, 0.5~2h is re-sintered in 1050~1150 DEG C, after multiple cold rolling-sintering, the thickness of plate reaches 0.1~0.5mm, density reach 7.33~7.49g/cm³；

(6) high temperature sintering is homogenized

Vacuum or restitutive protection 1~4h of atmosphere sintering in 1260~1340 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 7.34~7.50g/cm³。

2. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：The absolute ethyl alcohol of 200~500ml is added in step (1) mixed process according to mixed-powder per ton.

3. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：With high-energy ball milling or rush rotation method obtain grain size≤6 μm HIGH-PURITY SILICON iron powder.

4. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：Low energy mixer described in step (2) is conical mixer, V-arrangement batch mixer or drum mixer.

5. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：Step (2) adds that cellulose, paraffin micro mist or zinc stearate are water-insoluble as binder, and binder adds when mixing Dosage total amount is no more than the 0.8% of mixed-powder gross mass, while adds grease and absolute ethyl alcohol does passivator, plays passivation Si 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.

6. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：Step (5) is sintered, by 5~10 when re-sintering for 1050~1150 DEG C under vacuum-sintering or restitutive protection's atmosphere DEG C/min continuous warmings, during thickness of slab >=1mm, soaking time is 1~2h；Thickness of slab in 0.1~1mm, soaking time is reduced to 0.5~ 1h after sintered accumulation drafts reaches 30~45% every time, is sintered 1 time, is rolled down to from the powder base of 1.0~2.2mm again 0.1~0.5mm, it is necessary to be sintered 4~8 times again.

7. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：Overlapping places sintering plate during high temperature sintering, and interlayer is laid with MgO powder.

8. the method that High temperature diffusion sintering as described in claim 1 prepares Fe-6.5%Si thin strips with powder rolling, special Sign is：Support plate described in step (4) burns boat using W, Mo, corundum or zirconia ceramics.