CN1135573C - Method for producing unidirectional silicon steel plate with excellent magnetic character - Google Patents
Method for producing unidirectional silicon steel plate with excellent magnetic character Download PDFInfo
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Abstract
The present invention relates to a manufacturing method for an undirectional silicon steel plate with good magnetic characteristic. A silicon steel slab containing 0.01 to 0.10 wt% of C, 2.5 to 4.5 wt% of Si, 0.02 to 0.12 wt% of Mn, 0.005 to 0.10 wt% of Al and 0.04 to 0.015 wt% of N is thermally rolled after being heated to the temperature higher than 1280 DEG C to become a hot rolled steel plate; the annealing procedure is carried out according to the requirements; subsequently, one time cold rolling is carried out or the cold rolling with intermediate annealing is carried out more than two times to form a cold-rolled steel sheet; the undirectional silicon steel plate is produced by the decarburizing annealing procedure and the final annealing procedure. The finish temperature of hot precision rolling is from 900 DEG C to 1100 DEG C. The steel plate temperature T(t)(DEG C) from the finish temperature to the elapsed time t (t is longer than and equal to 2 S but is shorter than and equal to 6S) of the hot precision rolling satisfies that T(t) is shorter than and equal to FDT-FDT-700/6*t after being processed, wherein the FDT is the finish temperature (DEG C) of the hot precision rolling.
Description
The present invention relates to the manufacture method of grain-oriented silicon steel sheet, particularly about the manufacture method of the unidirectional silicon steel plate of low iron loss high magnetic flux density.
The unidirectional silicon steel plate uses mainly as the core material of transformer and other motor, requires to have the magnetic characteristic of good magnetic flux density and core loss value etc.
For making this folk prescription to silicon steel plate, the general method that adopts is, be to carry out hot rolling after the slab of 100～300mm heats under the temperature more than 1250 ℃ with thickness, cold rolling more than 2 times resulting hot rolled plate is cold rolling by 1 time or that have intermediate annealing forms final thickness of slab, after taking off charcoal annealing again, the coating annealing separation agent, carrying out afterwards with secondary recrystallization and purifying is the last annealing of purpose.
Promptly, at first, the heat slab is also carrying out hot rolling behind the solid solution inhibitor composition fully, controlled organizing again by the resulting primary recrystallization grain of annealing cold rolling and more than 1 time or 2 times more than 1 time or 2 times, then, in the annealing in the end by make this primary recrystallization grain 110}＜001〉carry out secondary recrystallization on the crystal grain in orientation and guarantee necessary magnetic characteristic.
For promoting such secondary recrystallization effectively, at first, the normal grain decentralized photo that grow up, that be referred to as inhibitor that will be used for suppressing primary recrystallization is controlled its precipitation state in the mode that even and suitable size is distributed to steel, and, make scope that the primary recrystallization grain is organized in whole thickness of slab for the crystal grain of suitable size and to become uniform distribution be important.As the representative of this inhibitor, use MnS, MnSe, ALN and the so minimum materials of the solubility in steel such as sulfide, selenides and nitride of VN.In addition, also use grain boundary segregation type elements such as Sb, Sn, As, Pb, Ce, Cu and Mo as inhibitor.
In a word, for obtaining good secondary recrystallization tissue, from separating out of the inhibitor hot rolling, the control of the inhibitor till the annealing of after this secondary recrystallization all is important condition.For guaranteeing better magnetic characteristic, we can say that the importance to the control of this inhibitor becomes more and more important.
Here, viewpoint from the control inhibitor, as being the conventional art of purpose to the temperature lag of batching with finish rolling from hot-rolled process, for example Japan hold public clear 38-14009 communique, spy open clear 56-33431 communique, spy open clear 59-50118 communique, spy open clear 64-73023 communique, spy open flat 2-263924 communique, spy open flat 2-274811 communique, spy open be able in the content that flat 5-295442 communique put down in writing known.
In the public clear 38-14009 communique of spy, a kind of manufacture method of crystal grain list directionality silicon electric steel is disclosed, it passes through hot-strip solutionizing under the temperature between 790 ℃ and 950 ℃ of the silicon electric steel of crystal grain list orientation is handled, carbon kept as solid solution and for preventing the formation of grain boundary carbide, from then on temperature begins to be quenched to sharp the temperature below 540 ℃, keep occurring 310～480 ℃ temperature of intragranular crystalline lens shape precipitate, at chilling after, by the direction-sense cold rolling and annealing of crystal grain list alternately occurring, and obtain crystal grain list directionality silicon electric steel.
Yet this technology is a kind of not adding the inhibitor composition, but based on the gimmick of separating out form of control carbide, and it will be controlled cooling rate and retention time that near the carbide 700 ℃ is separated out the humidity province.Therefore, in fact when this technology is applicable to the manufacturing of the unidirectional electromagnetic steel plate that contains ALN and MnSe, MnS, can not expect the characteristic improvement completely.
Open in the clear 56-33431 communique the spy, the method that coiling temperature is controlled at 700～1000 ℃ temperature range is disclosed, and after 700～1000 ℃ of high temperature batch with method of 10 minutes-5 hours of this coil insulation and after 700～1000 ℃ of high temperature batch with the method for this coil chilling.
Though this technology is the method for improving as the ALN of inhibitor of separating out dispersity, owing to, carry out the uneven charcoal that takes off to batch shape self-annealing after batching, thereby the formation of the cold rolling thereafter set tissue instability that also becomes, the bad increase of product performance.Particularly will cause the inhomogeneous of cooling rate batching water-cooled under the shape etc., this is to become the bad factor of product performance.
The spy open disclose in the clear 59-50118 communique hot rolled strip left the frame of last finish rolling after, be cooled to by following (1) with 7～40 ℃/second cooling rates, (2) temperature range calculated of formula, batch the also method of natural cooling afterwards, and hot rolled strip left after the last finishing stand, with 7～30 ℃/second be cooled to the temperature calculated by following (3) formula following after, batch again, and further water-cooled this batch the method for steel band.
(35×logV+515)℃ ……(1)
(445×logV-570)℃ ……(2)
(20×logV+555)℃ ……(3)
Wherein, V: the cooling rate (℃/second) of leaving last finishing stand hot rolled strip later on till batching the time
But, this technology to as if do not use the situation of ALN as inhibitor, thereby can not look to having independent uses ALN, or compound use ALN and MnSe or with the effect that relates to the manufacturing of unidirectional electromagnetic steel plate of MnS.
The spy open clear 64-73023 communique disclose in hot rolling, after finish rolling is finished up to the scope of average cooling rate that batches and coiling temperature at average cooling rate be more than 10 ℃/second, below 40 ℃/second the time, coiling temperature is more than 600 ℃, method below 750 ℃, and when average cooling rate was 40～80 ℃/second, coiling temperature was 550～750 ℃ a method.
It is identical that this technology and spy open the disclosed technology of clear 59-50118 communique, also with do not use MnS, MnSe as inhibitor as feature, do not relate to the relevant autofrettage of having used the unidirectional electromagnetic steel plate of ALN.In addition, even these are all relevant with cooling rate, end to the average cooling rate that batches but also only verified from finish rolling.It is as the present invention any to that is to say that it does not relate to, to as the precipitation state of the ALN of inhibitor or ALN and MnSe or with the compound precipitation state of MnS there to be the high temperature residence time of the finish rolling of essence influence after ending.
Open in the flat 2-263924 communique the spy, disclose that will to contain percentage by weight be C:0.02～0.100%, Si:2.5～4.5% and conventional inhibitor composition, and all the other carry out hot rolling for the blank plates of silicon steels that Fe and inevitable impurity constituted, do not carry out hot rolled plate annealing, and and then implement reduction ratio is cold rolling more than 80%, take off charcoal annealing, final annealing is made the method for unidirectional electromagnetic steel plate, wherein it is 750～1150 ℃ with temperature of hot-rolled end, at least keep temperature more than 700 ℃ more than 1 second after hot rolling ends, and coiling temperature is to be lower than 700 ℃ technology.
From reducing the viewpoint of expense, this technology is exactly to keep by high temperature after finish rolling, promotes crystallization again and improves tissue, and omitted the technology that hot rolled plate is annealed.Promoted the crystal energy again after the hot rolling to make tissue be improved, omit hot rolled plate annealing by this technology, but can not cause improving in the past and obtain good inhibitor precipitation state.In addition, this technology exists and must be abandoned such problem to the control of separating out of inhibitor owing to omitted hot rolled plate annealing.
And, open in the flat 2-274811 communique the spy, to contain percentage by weight is C:0.021～0.075%, the Si routine is: 2.5～4.5%, acid-solubility Al:0.010～0.060%, N:0.0030～0.000130%, below the S+0.405Se:0.014%, Mn:0.05～0.8%, and all the other carry out hot rolling for Fe and slab that unavoidable impurities constituted after less than 1280 ℃ temperature heating, then carry out hot rolled plate annealing as required, carry out reduction ratio then and be finally cold rolling more than 80%, and have the once above cold rolling of intermediate annealing as required, afterwards, enforcement is taken off charcoal annealing and last annealing with in the method for making the unidirectional electromagnetic steel plate, disclosing temperature of hot-rolled end is 750～1150 ℃, at least keep temperature more than 700 ℃ more than 1 second after hot rolling ends, and coiling temperature is lower than 700 ℃ technology.
This technology is attempted in the manufacture process of implementing the heating of low temperature slab, by keep high temperature after finish rolling, promotes crystallization again and improves magnetic characteristic, and make the magnetic characteristic stabilisation.Yet, but ALN solid solution in the heating of low temperature slab, and MnS, MnSe can not fully reach solid solution.Particularly, carrying out high temperature slab heating, making when using such hot rolling cooling in the autofrettage of the abundant solid solution of inhibitor and since inhibitor to separate out motion different, can not stably make the goods of excellent in magnetic characteristics.That is to say, owing in the operation of carrying out the heating of low temperature slab, the control of inhibitor is not prove effective, thereby exist the problem that stably to make the goods of excellent in magnetic characteristics.
Have again, open in the flat 5-295442 communique the spy, disclose the steel plate after the hot rolling final cold rolling reduction ratio be 80% with on carry out cold rolling method, wherein, steel plate after this hot rolling is after coming out from the last frame of hot finishing, has from below 850 ℃ to 600 ℃ the average cooling rate Ta (℃/second) and the pass of Ti amount being:
When Ta 〉=30 ℃/second, Ti≤0.003 weight %
Ta≥-7/3Ti+100
0.003 during＜Ti≤0.008 weight %
Ta≤-11/5Ti+206
Ta: ℃/second
Ti:10
-4Steel plate after the hot rolling of weight %.
But under situation about making according to this method, Ti residual in the goods forms oxide, nitride, exists the problem of the timeliness deterioration that causes iron loss.
Technology in the past evenly and with complete suitable size is disperseed in steel in order to make inhibitor, does not consider that hot finishing ends the back up to batching the thermal hysteresis of steel plate during this period of time.
And although the technology of being stipulated up to the cooling rate of batching after having pair hot finishing to end (it is disclosed that for example the spy opens clear 59-50118 communique), it is not with the purpose that is controlled to be to inhibitor, but separating out as target fine carbide.In addition, stipulate that the above-mentioned hot finishing back of ending only is to have stipulated average cooling rate up to the technology of the cooling rate of batching, particularly soon not concern of cooling after hot finishing ends.
More than these conventional arts can not realize that good inhibitor separates out control, therefore, can not make all good unidirectional silicon steel plate of magnetic flux density and core loss value two aspects.
Therefore, the purpose of this invention is to provide use separately ALN as inhibitor and compound use ALN and MnS or with the manufacturing technology of MnSe as the unidirectional silicon steel plate of the excellent in magnetic characteristics under the situation of inhibitor.
The present inventor is for realizing the aforementioned purpose of the present invention, by the result that studies in great detail at various factors in the hot-rolled process, cooling after hot finishing ended lags behind and is controlled and obtained good inhibitor and distribute, thereby can alleviate the secondary recrystallization fraction defective of goods, be achieved high magnetic flux density of the present invention and low iron loss.
That is, the present invention's (the 1st invention) is the manufacture method of the unidirectional silicon steel plate of excellent in magnetic characteristics, and it is to contain
C：0.01～0.10wt％ Si：2.5～4.5wt％
Mn：0.02～0.12wt％ Al：0.005～0.10wt％
After the blank plates of silicon steels of N:0.004～0.015wt% is heated to more than 1280 ℃, form hot rolled steel plate by hot rolling, implement hot rolled plate annealing afterwards as required, implement once cold rolling again or have cold rolling more than 2 times of intermediate annealing, form cold-rolled steel sheet, this cold-rolled steel sheet is passed through the operation of decarburizing annealing and the last annealing of enforcement again and make the unidirectional silicon steel plate, it is characterized in that, the finish rolling finishing temperature that makes this hot rolling is 900～1100 ℃ scope, from this hot finishing end begin with the steel billet temperature T (t) behind the elapsed time t of the definite scope of (1) formula institute (℃) handle in the mode of satisfied (2) formula.
2 seconds≤t≤6 seconds ... (1)
T(t)≤FDT-(FDT-700)/6×t ……(2)
Wherein: FDT: the hot finishing finishing temperature (℃).
And, the feature of the manufacture method of the unidirectional silicon steel plate of excellent in magnetic characteristics of the present invention (the 2nd invention) is that the blank plates of silicon steels of above-mentioned the 1st invention further contains a kind or 2 kinds of compositions selected from Se:0.005～0.06wt% and S:0.005～0.06wt%.
Above-mentioned the 2nd the invention in, preferably hot finishing end back 6 seconds to the cooling rate of batching steel plate below 25 ℃/second.
Below the experimental result that is drawn according to the present invention is described.
Fig. 1 is the figure of hot finishing finishing temperature and rolling back retention time and magnetic characteristic relation in the expression experiment 1.
Fig. 2 is the figure that the steel billet temperature after hot finishing ends in the expression experiment 2 lags behind.
Fig. 3 is that the hot finishing finishing temperature reaches from the steel billet temperature (T1) of hot rolling end of a period after 2 seconds and the figure of magnetic characteristic relation in the expression experiment 2.
Fig. 4 is the figure that the steel billet temperature after hot finishing ends in the expression experiment 3 lags behind.
Fig. 5 after hot finishing ends in the expression experiment 3, arrives the time Δ t of cooling temperature (T2) at the end and the figure of T2 and magnetic characteristic relation from T1.
Fig. 6 after hot finishing ends in the expression experiment 3, arrives the time Δ t of cooling temperature (T2) at the end and the figure of T2 and magnetic characteristic relation from T1.
Fig. 7 after hot finishing ends in the expression experiment 3, arrives the time Δ t of cooling temperature (T2) at the end and the figure of T2 and magnetic characteristic relation from T1.
Fig. 8 is the figure that the steel billet temperature after hot finishing ends in the expression experiment 4 lags behind.
Fig. 9 is the figure that the steel billet temperature after hot finishing ends in the expression experiment 4 lags behind.
Figure 10 is the figure that the steel billet temperature after hot finishing ends in the expression experiment 4 lags behind.
Figure 11 is the ideograph that the steel plate thermo-lag after the expression hot finishing influences the inhibitor precipitation state.
Figure 12 is illustrated in the experiment 6 with steel 4 as the sample steel, from hot finishing end the cooling rate after ending 6 seconds to 6 seconds temperature lag and from hot finishing and the figure of magnetic characteristic relation.
Figure 13 is illustrated in the experiment 6 with steel 5 as the sample steel, from hot finishing end the cooling rate after ending 6 seconds to 6 seconds temperature lag and from hot finishing and the figure of magnetic characteristic relation.
Figure 14 is illustrated in the experiment 6 with steel 4 as the sample steel, from hot finishing end the cooling rate after ending 6 seconds to 6 seconds temperature lag and from hot finishing and the figure of magnetic characteristic relation.
Figure 15 is illustrated in the experiment 6 with steel 4 as the sample steel, from hot finishing end the cooling rate after ending 6 seconds to 6 seconds temperature lag and from hot finishing and the figure of magnetic characteristic relation.
(experiment 1)
At first, for understand hot finishing end after the influence that inhibitor is separated out that lags behind of soon steel billet temperature test.
To contain C:0.07wt, Si:3.05wt%, Mn:0.06wt%, Al:0.020wt%, the steel of N:0.0090wt% carries out melting by vacuum fusion, is heated to 1200 ℃ after the casting again, is rolled into the steel plate of thickness 40mm.Adopt the test portion of thickness 40mm * width 300mm * length 400mm thus, 1300 ℃ of heating, make after the inhibitor composition melts admittedly, being rolled into thickness of slab is 2.3mm.Hot finishing finishing temperature (FDT) is each temperature of 700 ℃～1200 ℃, keeps 1～7 second time under this temperature.Chilling has afterwards kept after 1 hour air cooling to room temperature in 500 ℃ stove.After these hot rolled plates having been carried out hot rolled plate annealing, carry out once cold rolling, carry out intermediate annealing again, finally make the thick plate of 0.23mm by secondary cold-rolling.After this, in wet hydrogen atmosphere, carry out 850 ℃ of decarburizing annealings of 2 minutes, and applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, carry out 1200 ℃ of last annealing of 10 hours.
Magnetic characteristic to resulting goods like this is investigated, and Fig. 1 shows the result.Be the retention time after hot finishing ends with the transverse axis, the longitudinal axis is the hot finishing finishing temperature, with the magnetic of the corresponding goods of each condition with symbol 0 * expression.More than the 0 expression B8:1.88T, * the following resulting magnetic of expression B8:1.88T.
From test 1 result, can distinguish that in the steel billet temperature hysteresis after hot finishing ends, the hot finishing finishing temperature is more than 900 ℃ in order to realize that fine inhibitor separates out, obtains good magnetic.And, can distinguish hot finishing end the back up to the high temperature that carried out for 2 seconds keep also not can be to inhibitor separate out the bad especially influence of generation.
Secondly, for understanding fully the hot finishing influence that later steel billet temperature lagged behind in back 2 seconds that ends, carried out following experiment.
(experiment 2)
To contain C:0.08wt%, Si:3.20wt%, Mn:0.05wt%, Al:0.025wt%, the steel of N:0.0085wt% carries out melting by vacuum fusion, is heated to 1200 ℃ after the casting again, is rolled into the steel plate of thickness 40mm.Adopting thickness thus is the test portion of 40mm * width 300mm * length 400mm, 1300 ℃ of down heating, makes after the inhibitor composition melts admittedly, and being rolled into thickness of slab is 2.3mm.Hot finishing finishing temperature (FDT) is 900 ℃, 1000 ℃, 1100 ℃, is being lower than each temperature (T1) that is cooled under each hot finishing finishing temperature more than 800 ℃ after 2 seconds.After this chilling keeps being cooled to room temperature after 1 hour in 500 ℃ stove.This temperature lag is shown in Figure 2.These hot rolled plates carry out once cold rolling after having carried out hot rolled plate annealing, then implement intermediate annealing, by 2 cold rolling thickness that reach 0.23mm.Afterwards, in the environment of wet hydrogen atmosphere, carry out 850 ℃, 2 minutes decarburizing annealing, applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, carry out 1200 ℃, 10 hours last annealing.
Investigate at resulting goods like this, the result is shown in Figure 3.
Change the maximum temperature (T1c) that forms good magnetic according to the hot finishing finishing temperature.T1c satisfies formula (1) shown in Fig. 3 dotted line
T1c＝2/3×FDT+700/3 ……(1)
(experiment 3)
To contain C:0.04wt%, Si:3.00wt%, Mn:0.06wt%, Al:0.03wt%, the steel of N:0.0090wt% carries out melting by vacuum fusion, is heated to 1200 ℃ after the casting again, is rolled into the steel plate that thickness is 40mm.Adopt the test portion of thickness 40mm * width 300mm * length 400mm thus, 1300 ℃ of heating down, and make after the solutionizing of inhibitor composition, being rolled into thickness of slab is 2.3mm.The hot finishing finishing temperature is 900 ℃, 1000 ℃, 1100 ℃, is cooled to the corresponding T1c of hot finishing finishing temperature after 2 seconds kinds continuously, is cooled to T2 ℃ during second continuously at Δ t again.Chilling afterwards keeps after 1 hour air cooling to room temperature in 500 ℃ stove.This temperature lag is shown in Figure 4.After these hot rolled plates have carried out hot rolled plate annealing, implement once cold rolling, carry out intermediate annealing again, by 2 cold rolling thickness that reach 0.23mm.Afterwards, in the environment of wet hydrogen atmosphere, carry out 850 ℃, 2 minutes decarburizing annealing, applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, carry out 1200 ℃ of last annealing of 10 hours.
Magnetic characteristic at resulting goods like this is investigated, and its result is shown in Fig. 5-7.
Fig. 5-Fig. 7 is after being illustrated in hot finishing and ending, and steel billet temperature reaches the time Δ t of T2 and the schematic diagram of the relation of steel billet temperature T2 and magnetic characteristic from T1c shown in Figure 4.
Fig. 5 is the situation of FDT=900 ℃, T1c=833 ℃, and Fig. 6 is the situation of FDT=1000 ℃, T1c=900 ℃, and Fig. 7 is the situation of FDT=1100 ℃, T1c=966 ℃.
And, in Fig. 5-Fig. 7, the 0th, show more than the B8:1.88, *: the situation that is the following resultant magnetic of B8:1.88.
From Fig. 5-Fig. 7 as can be known, under the situation of and Δ t≤4 second (hot finishing end back 6 second) irrelevant, if T2≤700 ℃ then can obtain good magnetic characteristic with FDT.
From testing the conclusion that can draw in 2,3 be, under hot finishing ends back 2 seconds situation for being to be necessary condition below 700 ℃ during 6 seconds below the T1c and in the hot finishing back of ending.
Secondly, studied hot finishing end the back from 2 seconds to 6 seconds for the influence of the type of cooling.
(experiment 4)
To contain C:0.05wt%, Si:2.95wt%, Mn:0.061wt%, Al:0.023wt%, the steel of N:0.0085wt% carries out melting by vacuum fusion, is heated to 1200 ℃ after the casting again, is rolled into the steel that thickness is 40mm.Adopt the test portion of thickness 40mm * width 300mm * length 400mm thus, heat under 1300 ℃ and make after the solid solution of inhibitor composition, being rolled into thickness of slab is 2.3mm.When Fig. 8-Figure 10 shows hot finishing finishing temperature (FDT) and is 1000 ℃, from end cooling condition when beginning of hot finishing to 6 seconds.And, point, the hot finishing that hot finishing is ended back T1c ℃ some during 2 seconds of ending, and the hot finishing back line that 700 ℃ point is connected during 6 seconds of ending illustrates with thick line.This thick line is represented with (2) formula.
T(t)＝FDT-(FDT-700)/6×t ……(2)
T: from the elapsed time (second) that hot finishing ends and begins
T (t): at the steel billet temperature of t during second
After this chilling, and in 500 ℃ stove, keep after 1 hour air cooling to room temperature.These hot rolled plates are implemented once cold rolling after having carried out hot rolled plate annealing, then implement intermediate annealing, by 2 cold rolling thickness that finally reach 0.23mm.Afterwards, in the environment of wet hydrogen atmosphere, carry out 850 ℃, 2 minutes decarburizing annealing, applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, implement 1200 ℃, 10 hours last annealing.
Magnetic characteristic at resulting goods like this is investigated, and table 1 shows the result.And the bad generation area occupation ratio of so-called secondary recrystallization is exactly in the sheet after the annealing in the end, diameter is the following area occupation ratio that crystal grain occupied of 2mm.
From test 4 result, can judge, end between back 2～6 seconds if satisfy in hot finishing
T(t)≤FDT-(FDT-700)/6×t
Then can obtain good magnetic characteristic.
Table 1
| No. | Magnetic characteristic B 8(T) W17/50(W/Kg) | The bad generation area occupation ratio of secondary recrystallization (%) | ||
| A | 1.80 | 0.93 | 18 | Relatively |
| B | 1.90 | 0.87 | ＜1 | The present invention |
| C | 1.92 | 0.88 | ＜1 | The present invention |
| D | 1.84 | 0.95 | 12 | Relatively |
| E | 1.83 | 0.96 | 13 | Relatively |
| F | 1.89 | 0.86 | ＜1 | The present invention |
| G | 1.81 | 0.92 | 13 | Relatively |
| H | 1.83 | 0.93 | 11 | Relatively |
| I | 1.93 | 0.84 | ＜1 | The present invention |
Inferring of this reason is as follows.
Figure 11 shows steel plate thermo-lag after the hot finishing to the influence of the situation of separating out of inhibitor in the mode of pattern.
Inhibitor is after hot finishing ends, through thickization took place after some latent time.Reduction ratio is big more, or the hot finishing finishing temperature is low more under the situation of same reduction ratio, and is then should incubation period short more.And temperature is high more, and thickization all the more speed carried out.
Therefore, the zone that thick inhibitor forms is hachure portion zone shown in Figure 11.When steel plate is got among the figure thermo-lag shown in the X and during by hachure portion, it is very remarkable that the formation of thick inhibitor becomes.Its result, 2 times again crystallization become unstable, magnetic characteristic is bad.In the drawings in the thermo-lag shown in the Y, because without thickization of inhibitor zone, inhibitor is thickization not, thereby can obtain good magnetic characteristic.
Have, the steel billet temperature T (2) in experiment 2 after 2 seconds will satisfy T (2)≤2/3 * FDT+700/3 again, and being cooled to below 700 ℃ arrive 6 seconds in experiment 3 after is not necessary by the hachure zone among the figure.These 4 are confirmed by experiment.
Below, at beyond the ALN, discuss as the situation of inhibitor to containing MnSe and MnS.
(experiment 5)
The steel of composition shown in the table 2 is carried out melting by vacuum fusion, be heated to 1200 ℃ after the casting again, be rolled into the steel plate that thickness is 40mm.Adopt the test portion of thickness 40mm * width 300mm * length 400mm thus, after heating under 1300 ℃ and making the solutionizing of inhibitor composition, being rolled into thickness of slab is 2.3mm.The hot finishing finishing temperature is 1100～900 ℃, and the cooling condition when ending by 6 seconds from hot finishing is identical with the part of cooling figure shown in from Fig. 8 to Figure 10.After this chilling keeps 1 hour later air cooling to room temperature in 500 ℃ stove.These hot rolled plates are implemented once cold rolling after having carried out hot rolled plate annealing, then implement intermediate annealing, are 0.23mm by 2 cold rolling thickness that finally reach.Afterwards, in the environment of wet hydrogen atmosphere, carry out 850 ℃, 2 minutes decarburizing annealing, applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, carry out 1200 ℃, 10 hours last annealing.
Table 2
| C | Si | Mn | Al | N | | S | |
| Steel | |||||||
| 1 | 0.062 | 3.20 | 0.07 | 0.029 | 0.0094 | 0.017 | - |
| | 0.062 | 3.18 | 0.072 | 0.031 | 0.0093 | - | 0.010 |
| | 0.060 | 3.19 | 0.070 | 0.031 | 0.0094 | 0.010 | 0.008 |
Magnetic characteristic at resulting goods like this is investigated, if as shown in table 3.And, in table 3, put down in writing simultaneously and used and poor (Δ B, the Δ W) that test the resulting result of 4 same cooling figures.
Result by table 3 can judge, containing Se, S or containing simultaneously under the situation of Se and S, also with experiment 4 result similarly, even when hot finishing ends between back 2 seconds～6 seconds, satisfy T (t)≤FDT-(FDT-700)/6 * t, then can obtain good magnetic characteristic.
This is that MnSe or MnS have the cause as the inhibitor performance because except ALN.
Table 3
| No. | Steel grade | Cooling | Magnetic characteristic B 8(T) W17/50(W/Kg) | Magnetic characteristic difference Δ B Δ W | The bad incidence of secondary recrystallization (%) | |||
| 1 | Steel 1 | A | 1.80 | 0.93 | ±0 | ±0 | 16 | Relatively |
| 2 | ″ | B | 1.92 | 0.85 | ±0.02 | -0.02 | ＜1 | The |
| 3 | ″ | C | 1.94 | 0.86 | ±0.02 | -0.02 | ＜1 | The |
| 4 | ″ | D | 1.84 | 0.95 | ±0 | ±0 | 14 | Relatively |
| 5 | Steel 2 | D | 1.83 | 0.96 | -0.01 | +0.01 | 16 | Relatively |
| 6 | ″ | E | 1.84 | 0.95 | +0.01 | -0.01 | 13 | Relatively |
| 7 | ″ | F | 1.93 | 0.85 | +0.04 | -0.01 | ＜1 | The |
| 8 | ″ | I | 1.94 | 0.82 | +0.01 | -0.02 | ＜1 | The present invention |
| 9 | Steel 3 | G | 1.80 | 0.94 | -0.01 | +0.02 | 21 | Relatively |
| 10 | ″ | H | 1.83 | 0.92 | ±0 | -0.01 | 17 | Relatively |
| 11 | ″ | I | 1.95 | 0.82 | +0.02 | -0.02 | ＜1 | The present invention |
| 12 | ″ | F | 1.91 | 0.84 | +0.02 | -0.02 | ＜1 | The present invention |
Secondly, the influence of later half cooling rate having investigated from hot finishing end of a period back to the process batching.
(experiment 6)
The steel of composition shown in the table 4 is carried out melting by vacuum fusion, be heated to 1200 ℃ after the casting again, be rolled into the steel plate that thickness is 40mm.And steel 7 is same composition with experiment 4.Adopt the test portion of thickness 40mm * width 300mm * length 400mm thus, after heating under 1300 ℃ and making the solutionizing of inhibitor composition, implementing thickness of slab is the hot rolling of 2.3mm.The hot finishing finishing temperature is 1100～900 ℃, and the cooling condition when ending by 6 seconds from hot finishing is identical with the part of cooling figure shown in from Fig. 8 to Figure 10.After this use the cooling rate of 10～35 ℃/sec to be cooled to 500 ℃.In 500 ℃ stove, keep after 1 hour air cooling to room temperature afterwards.These hot rolled plates are implemented once cold rolling after having carried out hot rolled plate annealing, then implement intermediate annealing, are 0.23mm by 2 cold rolling thickness that finally reach.In the environment of wet hydrogen atmosphere, carry out 850 ℃, 2 minutes decarburizing annealing afterwards, applied be the annealing separation agent of main component with MgO after, in the environment of hydrogen atmosphere, carry out 1200 ℃, 10 hours last annealing.
Table 4
| C | Si | Mn | Al | N | | S | |
| Steel | |||||||
| 4 | 0.052 | 2.95 | 0.060 | 0.022 | 0.0084 | 0.015 | - |
| | 0.051 | 2.95 | 0.061 | 0.021 | 0.0081 | - | 0.012 |
| | 0.050 | 2.96 | 0.059 | 0.022 | 0.0083 | 0.011 | 0.009 |
| | 0.051 | 2.95 | 0.061 | 0.023 | 0.0085 | - | - |
Investigate at resulting goods like this.Figure 12 is in the expression steel 4, ends cooling rate after 6 seconds to the figure of magnetic characteristic influence from hot finishing.And, the cooling figure when ending from hot finishing by 6 seconds, 0 with Figure 10 in I, Δ and Fig. 8 in B, and the F among Fig. 9 be identical.Figure 13 is in the expression steel 5, ends to 6 seconds later cooling rates figure to the magnetic characteristic influence from hot finishing.And, ending from hot finishing by 6 seconds the later cooling figure, 0 with Figure 10 in I, Δ and Fig. 8 in B, and the F among Fig. 9 be identical.Figure 14 is in the expression steel 6, from hot finishing 6 seconds later cooling rates figure to the magnetic characteristic influence of ending.And, the cooling figure when ending from hot finishing by 6 seconds, 0 with Fig. 8 in C, Δ and Fig. 9 in F, and the B among Fig. 8 be identical.Figure 15 is in the expression steel 7, from hot finishing 6 seconds later cooling rates figure to the magnetic characteristic influence of ending.And, the cooling figure when ending from hot finishing by 6 seconds, 0 with Figure 10 in I, Δ and Fig. 8 in B, and the F among Fig. 9 be identical.
Result by Figure 12-Figure 14 can judge that containing Se or S and containing simultaneously under the situation of Se and S, when reaching 700 ℃～500 ℃, cooling rate is under the situation of 10～25 ℃/sec, and magnetic flux density improves.On the other hand, by the result of Figure 15, can not assert the effect of cooling rate when ALN adds separately especially.
Even except that ALN, contain under the situation of Se or S, or contain simultaneously magnetic characteristic is improved, also consider as follows.MnSe and MnS separate out when the hot finishing leading portion.After hot finishing ended, ALN preferentially separated out on MnSe that has separated out or MnS, forms compound precipitate.Because the cooling rate under this situation reaches compound precipitate slowly and becomes stable, thereby forms powerful inhibitor.Under the independent situation of ALN, can not determine such effect.
In the present invention, except that above-mentioned condition, creating conditions and can carry out in each operation of hot rolling, hot rolled plate annealing, pickling, intermediate annealing, cold rolling, decarburizing annealing, coating annealing separation agent and last annealing etc. with various known method.
As the silicon containing steel of this invention blank, be suitable for adding ALN separately, and compound interpolation ALN and MnSe or MnS are as inhibitor as inhibitor.If enumerating its one-tenth is grouped into, can be by following regulation.
C：0.01～0.10wt％
C is not only hot rolling, the cold rolling middle useful element of forming of even miniaturization, and is to the useful element of development in go ス (Ge Si) orientation, makes it contain 0.01wt% at least and is necessary.Yet, when the amount of C surpasses 0.10wt%, the difficulty because decarburization becomes, go ス (Ge Si) orientation confusion reigned in addition, thereby be limited to 0.10wt% on it.And best C amount is 0.03～0.08wt%.
Si：2.5～4.5wt％
Si helps to improve the resistivity of steel plate and reduces iron loss.Iron loss lowered DeGrain when the amount of Si was lower than 2.5wt%, and had been purifying and 2 times again in the last annealing under the high temperature that carries out of crystallization, thus because the magnetic characteristic that the abnormal randomization that can produce crystal orientation of α-γ can not obtain.On the other hand, infringement cold-rolling property when Si surpasses 4.5%, and make manufacturing become difficult.Gu this, the amount of Si is 2.5～4.5wt%.And preferably Si is in the scope of 3.0～3.5wt%.
Mn：0.02～0.12wt％
Mn is the effective element of crackle when preventing to produce hot rolling because of burning, can not obtain this effect when Mn is lower than 0.02wt%.On the other hand, when surpassing 0.12wt%, Si makes the magnetic characteristic variation when adding.Therefore, the amount of Mn is 0.02～0.12wt%.And preferably the scope of Mn is 0.05～0.10wt%.
Al：0.005～0.10wt％。
Al is the element that forms ALN and be used as inhibitor.The amount of AL can not be guaranteed restraint effectively when being lower than 0.005wt%, on the other hand, when Al surpasses 0.10wt%, can damage its effect, thereby Al is 0.005～0.10wt%.And optimum range is 0.01～0.05wt%.
N：0.004～0.015wt％
N is the element that forms ALN and be used as inhibitor.The amount of N can not be guaranteed restraint effectively when being lower than 0.004wt%, on the other hand, when the super 0.015wt% of N, can damage its effect, thereby, N be 0.004～0.015wt%. and, optimum range is 0.006～0.010wt%.
Se：0.005～0.06wt％
Se is the effective element that forms MnSe and be used as inhibitor.The amount of Se can not be guaranteed its effect effectively when being lower than 0.005wt%, on the other hand, destroyed this effect when Se surpasses 0.06wt%.Se should be the scope of 0.005～0.06wt% when therefore, being interpolation separately or compound interpolation.And optimum range is 0.010～0.030wt%.
S：0.005～0.06wt％
S forms MnS and is used as using of inhibitor to imitate element.Can not guarantee restraint effectively when the amount of S is lower than 0.005wt%, on the other hand, S can destroy this effect when being more than 0.06wt%, thereby no matter separately interpolation still is that compound adding closed S, and its scope all is 0.05～0.06wt%.And optimum range is 0.015～0.035wt%.
Have again, in the present invention, except that above-mentioned S, Se, Al as the inhibitor because Cu, Sn, Sb, Mo, Te, and Bi etc. also play favourable effect respectively, thereby can add above-mentioned various composition.The optimum addition range of these compositions is respectively: Cu, Sn:0.01～0.015wt%, Sb, Mo, Te, Bi:0.005～0.1wt%.And for these each inhibitor compositions, use and compound use can separately.
[embodiment]
To have chemical composition shown in the table 5, to be essentially thickness that Fe forms be that 200mm, width are that the silicon steel continuous casting plate blank of 1000mm is heated to 1430 ℃ in general gas heating stove and induction type heating furnace to remainder, make the solutionizing of inhibitor composition, after hot roughing, the hot rolling of the hot finishing finishing temperature shown in carry out table 5, with the control of the temperature lag shown in the table 5 cooling, batch again at 550 ℃.On this hot rolled plate, carried out after hot rolled plate annealing, the pickling, and after having passed through the cold rolling and intermediate annealing that reaches middle thickness of slab, carried out the cold rolling of final thickness of slab (0.23mm).Secondly, resulting cold-reduced sheet is carried out 850 ℃, 2 minutes decarburizing annealing in the environment that wet hydrogen encloses, and coating is the annealing separation agent of main component with MgO, the last annealing of carrying out 1200 ℃, 10 hours in the environment of hydrogen atmosphere becomes finished product.Carry out magnetic characteristic and the 2 times mensuration of crystallization fraction defective again at such finished product, its result is recorded in the table 5 in the lump.
As can be known from Table 5, according to method of the present invention, demonstrate high magnetic flux density and the low all good magnetic characteristic of iron loss, 2 times crystallization is also stable again.Relative therewith, in the comparative example beyond the scope of the invention, magnetic characteristic and 2 times crystallization-stable is all relatively poor more as can be known.
As mentioned above, the method according to this invention, use separately ALN make as inhibitor unidirectional electromagnetic steel plate and compound use ALN and MnSe or MnS as inhibitor manufacturing unidirectional electromagnetic steel plate in, eliminated the existing problem of previous methods, make excellent in magnetic characteristics the unidirectional electromagnetic steel plate manufacture for may.
Further, the method according to this invention, using ALN to make as inhibitor in unidirectional electromagnetic steel plate and compound use ALN and MnSe or the MnS manufacturing unidirectional electromagnetic steel plate separately, promoted to help effectively to improve the development of the secondary recrystallization tissue of magnetic characteristic, thereby the unidirectional electromagnetic steel plate of making the excellent in magnetic characteristics with high magnetic flux density and low iron loss characteristic becomes possibility.
Table 5
| Number | C (wt％) | St (wt％) | Mn (wt％) | Al (wt％) | N (wt％) | Sa (wt％) | S (wt％) | FDT (℃) | Hot rolling end the temperature of back x during second (℃) | 6 seconds later cooling rates (℃/s) | Magnetic characteristic | 2 crystallization fraction defectives (%) again | Embodiment or comparative example | |||||
| x＝2 | x＝3 | x＝4 | x＝5 | x＝6 | B8(T) | W17/50(W/Kg) | ||||||||||||
| 1 | 0.055 | 3.00 | 0.075 | 0.025 | 0.0090 | - | - | 1050 | 990 | 900 | 760 | 700 | 660 | 35 | 1.79 | 0.94 | 24 | Comparative example |
| 2 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 1050 | 880 | 800 | 750 | 700 | 660 | 35 | 1.91 | 0.86 | ＜1 | Embodiment |
| 3 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 1050 | 880 | 800 | 750 | 700 | 660 | 15 | 1.90 | 0.85 | ＜1 | Embodiment |
| 4 | 0.070 | 3.20 | 0.070 | 0.020 | 0.0080 | 0.015 | - | 1000 | 860 | 850 | 840 | 770 | 670 | 30 | 1.80 | 0.92 | 19 | Comparative example |
| 5 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 1000 | 810 | 790 | 780 | 720 | 640 | 30 | 1.94 | 0.85 | ＜1 | Embodiment |
| 6 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 1000 | 810 | 790 | 780 | 720 | 640 | 20 | 1.97 | 0.81 | ＜1 | Embodiment |
| 7 | 0.060 | 3.05 | 0 060 | 0.022 | 0.0085 | - | 0.011 | 950 | 840 | 810 | 790 | 770 | 760 | 34 | 1.81 | 0.92 | 22 | Comparative example |
| 8 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 950 | 780 | 750 | 720 | 700 | 680 | 34 | 1.94 | 0.85 | ＜1 | Embodiment |
| 9 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 950 | 780 | 750 | 720 | 700 | 680 | 23 | 1.98 | 0.81 | ＜1 | Embodiment |
| 10 | 0.050 | 2.95 | 0.065 | 0.020 | 0.0095 | 0.014 | 0.009 | 900 | 870 | 840 | 800 | 670 | 640 | 32 | 1.83 | 0.91 | 18 | Comparative example |
| 11 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 900 | 800 | 710 | 680 | 660 | 640 | 32 | 1.95 | 0.84 | ＜1 | Embodiment |
| 12 | ″ | ″ | ″ | ″ | ″ | ″ | ″ | 900 | 800 | 710 | 680 | 660 | 640 | 12 | 1.98 | 0.80 | ＜1 | Embodiment |
Claims (3)
1. the manufacture method of the unidirectional silicon steel plate of an excellent in magnetic characteristics, to contain C:0.01～0.10wt%, Si:2.5～4.5wt%, Mn:0.02～0.12wt%, Al:0.005～0.10wt%, after the blank plates of silicon steels of N:0.004～0.015wt% is heated to more than 1280 ℃, become hot rolled steel plate by hot rolling, after this carry out hot rolled plate annealing as required, then carry out once cold rolling, or be inserted with cold rolling more than 2 times of intermediate annealing, form cold-rolled steel sheet, this cold-rolled steel sheet manufactures the unidirectional silicon steel plate through implementing decarburizing annealing and last operation of annealing, it is characterized in that: the finish rolling finishing temperature of this hot rolling is 900～1100 ℃ a scope, from this hot finishing end to by (1) formula behind the elapsed time t of definite scope steel billet temperature T (t) ℃ handle in the mode that satisfies (2) formula.
2 seconds≤t≤6 seconds ... (1)
T(t)≤FDT-(FDT-700)/6×t …(2)
Wherein: FDT: hot finishing finishing temperature ℃
2. according to the manufacture method of the unidirectional silicon steel plate of the described excellent in magnetic characteristics of claim 1, it is characterized in that: blank plates of silicon steels also contains a kind or 2 kinds of compositions choosing from Se:0.005～0.06wt% and S:0.005～0.06wt%.
3. according to the manufacture method of the unidirectional silicon steel plate of the described excellent in magnetic characteristics of claim 2, it is characterized in that: hot finishing end 6 seconds to the steel plate cooling rate of batching be below 25 ℃/second.
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| CNB961089202A CN1135573C (en) | 1996-03-30 | 1996-03-30 | Method for producing unidirectional silicon steel plate with excellent magnetic character |
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|---|---|---|---|
| CNB961089202A CN1135573C (en) | 1996-03-30 | 1996-03-30 | Method for producing unidirectional silicon steel plate with excellent magnetic character |
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| CN1135573C true CN1135573C (en) | 2004-01-21 |
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| CN103526000A (en) * | 2013-09-13 | 2014-01-22 | 任振州 | Preparation method of low-carbon high-manganese oriented silicon steel sheet |
| CN107429307B (en) * | 2015-04-02 | 2019-05-14 | 新日铁住金株式会社 | The manufacturing method of one-way electromagnetic steel plate |
| CN107043847B (en) * | 2016-02-09 | 2021-06-18 | 株式会社东北磁材研究所 | Heat treatment device for laminated body of amorphous alloy thin strip and soft magnetic core |
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