CN103667879B - The non-oriented electrical steel that magnetic property and mechanical performance are good and production method - Google Patents

Abstract

The non-oriented electrical steel that magnetic property and mechanical performance are good, its component and weight percent content are: C≤0.003%, Si:0.5～1.5%, Als:0.1～0.85%, Mn:0.1～0.9%, S≤0.003%, N≤0.003%, the Sn of addition≤0.15% or Nb or its both mixing, all the other are Fe and inevitable impurity; And limiting Si+Als+Mn 1.5～2.2%, (Als+Mn)/Si will meet 0.8～1.4 simultaneously; Production stage: continuous casting billet is heated; Control hot rolling finishing temperature at 750～850 DEG C; Batch; Carry out; After pickling, be cold-rolled to finished product thickness; Recrystallization annealing; Stress relief annealing. The present invention is by the accurate control to composition, and after Low Temperature Hot Rolling and normalizing, obtains coarse grains, hot rolled plate tissue uniformly, then obtains through pickling, cold rolling, recrystallization annealing the cold-reduced sheet that hardness is 110～140HV, passes through final stress relief annealing, iron loss P_1.5/50≤ 2.50W/kg, magnetic strength B₅₀>=1.75T, good processability.

Description

The non-oriented electrical steel that magnetic property and mechanical performance are good and production method

Technical field

The present invention relates to a kind of non-oriented electrical steel and production method, belong to particularly a kind of magnetic property and mechanical performance excellentGood non-oriented electrical steel and production method.

Background technology

For energy-conservation and environmental protection, require to improve electric efficiency, dwindle motor volume and reduce noise, high efficiency motor steel isOne of the research emphasis of non-oriented electrical steel and focus in recent years. High efficiency motor requires non-oriented electrical steel to have good magneticEnergy and mechanical performance, i.e. iron loss loss is low, and magnetic flux density is high and the moderate punching of hardness is good, intensity is high. Improve electrical sheet magneticCan and the main path of mechanical performance be exactly component content rationally, moderate crystal grain size, texture orientation excellence, therefore, need toolThere are correct one-tenth subsystem and fabrication process condition.

Chinese Patent Application No. is the patent documentation of 200980152838.X, and it discloses one client is had to heightThe preparation method of machinability non-oriented electromagnetic steel sheet and this steel plate: described steel plate has ferromagnetism after processing by SRA, its one-tenthBe divided into containing Si:0.2-1.0wt.%, Al:0.9-2.0wt.%, Mn:0.1-0.5wt.%, P:0.01-0.05wt.%, all the other be iron andOther inevitable impurity, wherein Si and Al meet equation 1.4≤Si+Al≤2.4 and 1≤Al/Si≤5; By becoming sub-controlThe Vickers hardness that system and annealing process improve to obtain and texture are improved and are obtained higher magnetic strength and low iron loss, and its iron loss isP1.5/5≤2.7W/kg, magnetic strength B50 is between 1.74-1.75T. The document, due to high containing Al, is 0.9-2.0wt.%, is giving birth toIn product, easily produce as watered steel difficulty, corrugation, oxidation, the deficiency that is difficult to pickling, and increase cost.

Chinese Patent Application No. is 200510027404.0 patent documentation, and it discloses a kind of low iron loss high magnetic sensing cold millingThe production method of non-oriented electrical steel. More than document normalizing process requires to be elevated to Ac1 with the firing rate of 5-15 DEG C/s,1100 DEG C are carried out 10s below to the soaking between 90s, then adopt two-stage process cooling, and hot stage is cold with≤15 DEG C/s'sBut speed is cooled to steel band below 650 DEG C, then under the prerequisite with guarantee template, is cooled to below 80 DEG C. The deficiency of its existenceBe the high and technique more complicated of normalizing temperature, programming rate and cooling rate are wayward, cause operation easier large.

Chinese Patent Application No. is 200610023208.0 patent documentation, discloses one and has utilized cover annealing processingObtain the method for low-iron loss high-magnetic strength non-oriented electrical steel band. Under bell furnace condition, implement perhydro annealing, annealing temperature 700-900 DEG C, be incubated 5 hours. Obtain by this method thick limit portion grain structure (more than 150 μ m), final cold-reduced sheet annealingTime (0kl) texture strong, thereby obtain the non-oriented electrical steel strip of high-magnetic induction, low-iron loss. The deficiency of its existence: due to hot rolled plate ratioThicker, be generally 2.0-2.6mm, make heat conduction slow, while adopting bell furnace to carry out normalizing, need the insulation of long period to protectThe card volume heart and the outer ring temperature difference are less than 30 DEG C, cause the production cycle long.

China Patent Publication No. is the patent documentation of CN101306434A, and it discloses a kind of low carbon low silicon no-aluminum half-techniqueThe preparation method of non-oriented electrical steel. Processing step is Chemical Composition in Cast Billet: than C≤0.005%, and Si=0.1%-1.0%, Mn≤0.35%, S≤0.01%, N≤0.0080%, P≤0.08%, O≤0.015%, all the other are Fe and inevitable impurity; Strand warpHot rolling, pickling and cold rolling laggard interline annealing, the cold rolling and user's stress relief annealing of critical strain obtains half technique without gettingTo electrical sheet. Product magnetic P_1.5/50=3.45-5.05W/kg, magnetic strength B₅₀=1.69-1.76T. Although its production cost is low, ironDamage higher, different with the improvement of hot rolling technology from the application's the accurate proportioning of main component system.

Summary of the invention

The object of the invention is for prior art exist iron loss high, though iron loss has reduction after stress relief annealing,Also there is deterioration in magnetic strength, simultaneously mechanical performance is also poor, and can not meet high efficiency motor energy-saving and environmental protection, lightness requires notFoot, and pursue high Si+Al content to pursue high cleanliness on composition and strictly control impurity content, increased smelting difficulty andCost; In technique, pursue high normalizing temperature and annealing temperature, to obtain thick grain structure, cause interior oxidation and interior nitrogenChange serious phenomenon; Although half Process is produced non-orientation silicon steel recrystallization annealing temperature low (650-800 DEG C), increase flatWhole (under critical pressure) operation, the production cycle is elongated, the deficiency that its lumber recovery reduces; It obtains after being to provide a kind of stress relief annealingProduct texture be orientated that (100) plane texture intensity is high, plate property: hardness is 110～140HV, moves back through final destressingFire, iron loss P_1.5/50≤ 2.50W/kg, magnetic strength B₅₀>=1.75T, magnetic property and mechanical performance that magnetic property and mechanical performance are good are excellentGood non-oriented electrical steel and production method.

Realize the measure of above-mentioned purpose:

The non-oriented electrical steel that magnetic property and mechanical performance are good, its component and weight percent content are: C≤0.003%, Si:0.5～1.5%, Als:0.1～0.85%, Mn:0.1～0.9%, S≤0.003%, N≤0.003%, addition≤0.15% Sn or Nb or its both mixing, all the other are Fe and inevitable impurity; And limit Si+Als+Mn 1.5～2.2% and (Als+Mn)/Si to meet 0.8～1.4 simultaneously; Plate property: hardness is 110～140HV, through finally go shouldPower annealing, iron loss P_1.5/50≤ 2.50W/kg, magnetic strength B₅₀≥1.75T。

Produce the method for the non-oriented electrical steel that magnetic property and mechanical performance are good, its step:

1) smelt also continuous casting and become base;

2) continuous casting billet is heated to 1000～1150 DEG C;

3) carry out hot rolling, control finishing temperature at 750～850 DEG C;

4) batch, control coiling temperature at 550～650 DEG C;

5) carry out normalizing, normalizing temperature is 850～1100 DEG C, and is incubated 30～180 seconds;

6) after pickling, be cold-rolled to finished product thickness;

7) carry out recrystallization annealing, annealing temperature is 700～900 DEG C, and is incubated 60～180 seconds;

8) carry out stress relief annealing, at 750～850 DEG C, eliminate stress, and be incubated 1～2 hour.

The effect of each element and master operation in the present invention

C: be harmful element, can produce magnetic aging when content exceedes 0.0030% and cause the iron loss in use to worsen, therefore mustMust be controlled at≤0.0030%.

Si: add Si can increase resistivity in non-oriented electrical steel, reduce iron loss; But increasing, Si content can worsen magneticInduction, therefore, for ensureing that superelevation magnetic strength need control the content of Si, Si content is between 0.5%～1.5%.

Al: can increase resistivity with Si is the same, reduce iron loss, magnetic strength is also had to certain deterioration, therefore, the content of AlBe controlled in 0.1～0.85% scope; Increase Al content and be conducive to coarse grains and texture after stress relief annealing and improve, reduce ironDamage.

Mn: improve hot rolled plate tissue and texture, impel (100) and (110) component to strengthen, (111) component weakens, and improves magneticProperty; Form MnS with S, thick MnS is conducive to grain growth and reduces iron loss, and manganese is γ phase region forming element, when exceeding 1.0% meetingReduce ferrite region, reduce finished product annealing temperature and be unfavorable for growing up of crystal grain, therefore Mn content is 0.1%～0.9%;

Sn or Sb add one or both: total amount is no more than 0.15%. Sn or Sb, in former grain boundaries segregation, can make (100)[uvw] component is strengthened and grain coarsening also hinders the formation of (111) recrystallization nucleus, thereby improves magnetic, but content exceedes0.2% can crack when cold rolling rolling can not be carried out, and can increase cost;

The value of Si+Al+Mn is preferably 1.5～2.2%: because Si, Al and Mn three can improve resistivity, reduce iron loss,Therefore, the value of Si+Al+Mn is more than 1.5. If but Si+Al+Mn > 2.2 is unfavorable to magnetic strength, especially magnetic strength reduces, andAnd cold rolling difficulty.

In order further to improve performance, coordinate iron loss and magnetic strength relation, improve hardness and intensity, need be Als+Mn and SiBe controlled in 0.8～1.4 scope. It is close with Si that Al improves resistivity degree, is equivalent to 1/3 of Si and improve hardness degree; MnImprove resistivity and be equivalent to 1/2 of Si, and improve hardness degree and reduce magnetic strength degree lower than Si. Therefore control Als+Mn and SiRatio between 0.8～1.4, (Als+Mn)/0.8 of Si < hardness increase, magnetic strength reduce; (Als+Mn)/Si > 1.4, mistakeThe Al of amount easily produces in process of production oxide and worsens magnetic, and cost increases.

The present invention also improves degree of purity by control S and N content and reaches high magnetic strength and low iron loss while and deposit. S, N are in warmSome solid solution again while rolling in process heating of plate blank, when when hot rolling, the trickle precipitate of MnS, AlN can suppress final annealingThe growth of crystal grain, thus worsen iron loss, and therefore, its content all must be below 0.0030%.

Secondly manufacturing process and principle are described.

Why slab heating temperature being controlled to 1000 DEG C≤ST≤1150 DEG C, is because heating-up temperature is as lower than 1000DEG C, can in the time of hot rolling, bounce-back increase, depress difficulty; Heating-up temperature, as being greater than 1150 DEG C, can make MnS, AlN etc. in slab separate outThing solid solution, can separate out the growth that tiny field trash suppresses annealing grains when hot rolling, causes iron loss to increase, and magnetic strength reduces.

Why control finish to gauge temperature 750 DEG C≤FT≤850 DEG C, because finishing temperature is as lower than 750 DEG C, hot rolling bounce-back increasesGreatly, rolling difficulty, hot rolled plate thickness is wayward; Finishing temperature, as higher than 850 DEG C, causes the quickening of recrystallization speed when hot rolling,Worsen hot rolled plate tissue, cause production board iron loss to increase, magnetic strength reduces; Therefore,, through test, be chosen between 750 DEG C～850 DEG CCarry out finish to gauge and can reduce the tiny recrystal grain in hot rolled plate top layer, obtain the Deformation structure consistent with heart portion of limit portion. Fig. 1 isSteel plate organization chart when 780 DEG C of finishing temperatures, as can be seen from the figure hot rolled plate is deformation band tissue, this Deformation structure's mark toolHave few compared with high energy storage and recrystallization nucleus.

At 850～1100 DEG C, be incubated the normalizing of 30～80s, make hot rolled plate complete recrystallization, even grain sizeAnd coarsening; And make precipitate (MnS, AlN etc.) further assemble alligatoring, the inhibition to grain growth while reducing annealing; SimultaneouslyCan make (100), (110) texture that magnetic is favourable increase, disadvantageous γ texture component weakens, and improves the magnetic of product. LowAt the temperature of 850 DEG C, carry out normalizing, because time inside furnace is short, the low crystal grain of temperature is tiny, unfavorable to magnetic; Make higher than 1100 DEG CIncrease cost. Fig. 2 be 950 DEG C insulation 60s normalizing after organization chart. As can be seen from Figure 2, the hot rolled plate after normalizingGrain structure is thick, even, is conducive to the improvement of stress relief annealing texture, improves ratio and the crystal grain of favorable textures such as (100)Alligatoring, thereby magnetic is improved greatly.

Recrystallization annealing is carried out 700～900 DEG C of annealing, temperature retention time 60～180s in continuous annealing furnace. Recrystallization temperatureIt is incomplete that degree is less than 700 DEG C of recrystallizations, and favorable texture can not fully generate; Annealing temperature is greater than 900 DEG C of coarse grains, processing punchingPiece performance is poor.

The present invention compared with prior art, by the accurate control to composition, obtains brilliant after Low Temperature Hot Rolling and normalizingThick, the uniform hot rolled plate tissue of grain, then obtaining hardness through overpickling, cold rolling, recrystallization annealing is the cold of 110～140HVRoll plate, after shearing through final stress relief annealing, iron loss P_1.5/50≤ 2.50W/kg, magnetic strength B₅₀>=1.75T, and crystallite dimensionModerate with hardness, good processability.

Brief description of the drawings

Steel plate organization chart when Fig. 1 is 780 DEG C of finishing temperatures;

Fig. 2 is the steel plate organization chart after the normalizing of 950 DEG C of insulation 60s.

Detailed description of the invention

Below the present invention is described in detail:

Table 1 is component and the weight percent content list of various embodiments of the present invention and comparative example;

Table 2 is the main technologic parameters value list of various embodiments of the present invention and comparative example;

Table 3 is the performance test results lists of various embodiments of the present invention with regard to comparative example.

Each embodiment all produces according to following steps:

1) smelt also continuous casting and become base;

2) continuous casting billet is heated to 1000～1150 DEG C;

3) carry out hot rolling, control finishing temperature at 750～850 DEG C;

4) batch, control coiling temperature at 550～650 DEG C;

5) carry out normalizing, normalizing temperature is 850～1100 DEG C, and is incubated 30～180 seconds;

6) after pickling, be cold-rolled to finished product thickness;

7) carry out recrystallization annealing, annealing temperature is 700～900 DEG C, and is incubated 60～180 seconds;

8) carry out stress relief annealing, at 750～850 DEG C, eliminate stress, and be incubated 1～2 hour.

The component of table 1 various embodiments of the present invention and comparative example and weight percent content list (wt%)

Table 2 various embodiments of the present invention and comparative example hot rolling technology and magnetic property list

The Performance Detection list of table 3 various embodiments of the present invention and comparative example

As can be seen from Table 3, the hardness before non-oriented electrical steel stress relief annealing of the present invention all between 110-140,Ensure good punching, there is easy processing; Iron loss P after stress relief annealing_1.5/50At 2.3-2.5W/kg, magneticSense B₅₀All be greater than 1.750T and realize low iron loss and high magnetic strength and coordinate, obtained magnetic property and mechanical performance good without oriented electricSteel.

Comparative example 1, because Als+Mn/Si is 0.3, is less than the application and sets requirement, and 740 DEG C of hot rolling finishing temperature < are720 DEG C, so magnetic is poor, hardness is high; Comparative example 2 is because Si content is that 1.63%, Als is 0.95%, and Si+Als+Mn is3.17% is all greater than the alloy upper limit that the application requires, through the high-temperature final rolling of 880 DEG C, and final products magnetic difference, hardness is high; RightThe Si content of ratio 3, due to lower than 0.5%, is 0.45%, and Si+Als+Mn is less than 1.5%, and the heating-up temperature of hot rolling is 1250DEG C, higher than the application's requirement, final products magnetic difference, hardness is soft. Therefore, in order to obtain magnetic property and mechanical performance is comprehensiveCan need to meet the condition that the application requires by good non-oriented electrical steel.

Above-described embodiment only exemplifies for the best, and is not the restriction to embodiments of the present invention.

Claims (2)

1. the good non-oriented electrical steel of magnetic property and mechanical performance, its component and weight percent content are: C≤0.0023%,Si:0.77～1.5%, Als:0.1～0.32% or 0.42 ~ 0.62%, Mn:0.1～0.19% or 0.52 ~ 0.9%, S≤0.003%, N≤ 0.0019%, the Sn of addition≤0.15% or Nb or its both mixing, all the other are Fe and inevitable impurity; And limitSi+Als+Mn 1.62～1.68 or 1.75 ~ 2.2% and (Als+Mn)/Si want simultaneously 0.83 ~ 1.04 or 1.12～1.33Meet; Plate property: hardness is 110～140HV, through final stress relief annealing, iron loss P_1.5/50≤ 2.50W/kg, magnetic strength B₅₀≥1.75T。

2. the method for the non-oriented electrical steel that the magnetic property described in production claim 1 and mechanical performance are good, its step:

1) smelt also continuous casting and become base;

2) continuous casting billet is heated to 1000～1150 DEG C;

3) carry out hot rolling, control finishing temperature at 750～790 DEG C;

4) batch, control coiling temperature at 550～650 DEG C;

5) carry out normalizing, normalizing temperature is 910～1100 DEG C, and is incubated 30～180 seconds;

6) after pickling, be cold-rolled to finished product thickness;

7) carry out recrystallization annealing, annealing temperature is 700～900 DEG C, and is incubated 60～180 seconds;

8) carry out stress relief annealing, at 750～850 DEG C, eliminate stress, and be incubated 1～2 hour.