CN103882289A - Production method for manufacturing cold-rolled oriented silicon steel with high magnetic strength by using generally oriented steel raw material - Google Patents

Abstract

The invention discloses a production method for manufacturing cold-rolled oriented silicon steel with high magnetic strength by using a generally oriented steel raw material. The method comprises the following steps: (1) smelting, carrying out vacuum treatment, refining and continuously casting into a billet; (2) carrying out hot rolling; (3) normalizing and pickling; (4) wherein the single cold rolling pressure ratio is greater than or equal to 82%; (5) decarburizing annealing temperature; (6) annealing at high temperature, setting low thermal insulation of two steps, and high thermal insulation of one step, wherein the nitriding amount of an N gas is greater than or equal to 16ppm; (7) stretching, leveling and annealing, namely, pickling, coating, annealing and leveling. Gauss texture and nucleation are formed by the big pressure rate by cold rolling one time or twice, inclusions with enough quantity are formed by nitriding at an earlier stage of high-temperature annealing, development, stabilization and perfection of gaussian grains are recrystallized for the second time by using the enhanced inhibiting effect. By adopting the process, the magnetic property and the orientation degree of the product are improved when the silicon steel is produced by using the generally oriented silicon steel material, so that the property of the oriented silicon steel is improved, and high grade of cold-rolled oriented silicon steel 27Q105 is produced.

Description

Manufacture the production method of high magnetic sensing cold milling oriented silicon steel with general oriented steel raw material

Technical field

the invention belongs to the production method of manufacturing high magnetic sensing cold milling oriented silicon steel with general oriented steel raw material.

Background technology

1, the production method of general cold-rolled orientation silicon steel and the trade mark that can produce are as follows traditionally:

(1) use converter (or electric furnace) steel-making, carry out vacuum-treat, composition refining and alloying, continuous casting becomes slab, its basic chemical composition is: Si(2.5～5.0), C(0.01～0.10), Mn(0.02～0.10), S(0.01～0.05), Als(0.01～0.05), N(0.003～0.015), some composition systems also contain one or more in the elements such as Mo, Sb, Cr, B, Bi, all the other are iron and inevitable impurity element, and product also may contain Cu sometimes;

(2) before slab hot rolling, in special heating furnace, be heated to the temperature of 1400 ℃ of left and right, and carry out above insulation in 30 minutes, make the abundant solid solution of favourable inclusion, to separate out Second Phase Particles tiny, disperse in silicon steel matrix in course of hot rolling subsequently---be inhibitor;

(3) after Hot Rolled Plate Normalizing (or not normalizing), carry out pickling, remove the iron scale of steel strip surface;

(4) (in traditional method, mostly general oriented silicon steel is with twice cold rolling finished product thickness that just can roll to roll finished product thickness by twice cold-rolling practice that comprises process annealing, so need there is process annealing between cold rolling twice, only have the another kind of high magnetic induction grain-oriented silicon steel can be with a rolling);

(5) carry out decarburizing annealing and the annealing separating agent of coating take magnesium oxide as main component, and the carbon in steel plate is taken off to the level of finished product magnetic that do not affect (generally should below 30ppm);

(6) in high-temperature annealing process, occur successively: MgSiO ₄the formation reaction (magnesium oxide of coating and the silicon dioxde reaction of surface of steel plate generate) of bottom, generation, growth and the growth of secondary recrystallization, (this stage is the final stage in high-temperature annealing process part to purify steel, element except iron and silicon in silicon steel is removed totally as much as possible, be included in oriented silicon steel production process above as favourable be mingled with protected and before secondary recrystallization occurs as the composition such as N, S of inhibitor integral part) physical-chemical reaction, obtain the cold-rolled orientation silicon steel that orientation degree is high, iron loss is low;

(7) be coated with insulating coating and carry out stretching and leveling annealing in steel strip surface, generally can obtain the 30Q120～30Q140 of commercial applications form, the cold-rolled orientation silicon steel product of 27Q130～27Q 140 trades mark.

2, the distinguishing feature of the production method of the general cold-rolled orientation silicon steel of tradition has:

(1) inhibitor starts just to form from steel-making, adjusting it, control in each operation subsequently, lose owing to carrying out successively middle inhibitor in each operation, must be made up by rights, to play a role to crucial moment, after having acted on, to from steel, remove;

(2) the slab heat before hot rolling, Heating temperature, up to 1400 ℃ of left and right, is the Limiting Level of general process furnace, the cooling control of hot-rolling line is also the limit of existing hot rolling technology;

(3) the key of production technology is to control tissue, the texture of the each stage steel plate of each operation, and the form of inhibitor, quantity and behavior;

(4) because slab heating temperature is high, process furnace needs frequent repairing, and utilising efficiency is low, and steel billet scaling loss is large simultaneously, energy consumption is high, and hot rolling crimping splits greatly, causes cold rolling process to produce difficulty, and lumber recovery is low, and comprehensive cost is high;

(5) the complex manufacturing of the general cold-rolled orientation silicon steel of high temperature heating of plate blank, with high content of technology, and investment of production equipment is large.This technology is through the development of over half a century, very ripe, for very large contribution has been made in the development of electric power, electronic industry, but just because of its complex manufacturing, with high content of technology, the blockade on new techniques of investment of production equipment greatly and between manufacturing enterprise, has limited the very fast development of its output, especially the country of rapid economic development as China, past contact can not meet the market requirement of quick increase.

3, relevant improvement and patented technology

In order to address these problems, in long-term production practice and in research work, people grope and have developed some successful ways, are now summarized as follows:

(1) the method for introducing in Japanese patent laid-open 5-112827, its chemical composition is: [C] 0.025 ~ 0.075%, Si2.90 ~ 4.50%, S≤0.012%, Als0.010 ~ 0.060%, N≤0.010%, Mn0.08 ~ 0.45%, P0.015 ~ 0.045%, all the other are Fe and inevitable inclusion, after 1200 ℃ of following heating of slab, carry out hot rolling, with one just time cold rolling or be rolled down to final finished thickness with more than twice method of process annealing, after decarburizing annealing, steel band carries out continuous nitriding in traveling process, after being coated with magnesium oxide separant, carry out high temperature annealing, the all good oriented silicon steels of production magnetic and bottom layer quality.Nitriding method continuously: protective atmosphere is the mixed gas of hydrogen and nitrogen, wherein NH ₃content is more than 1000ppm, and oxygen gesture is that PH2O/PH2≤0.04 nitriding temperature is 500 ~ 900 ℃.

(2) POSCO Co., Ltd. of Korea S, its low-temperature oriented silicon steel chemical composition is: [C] 0.020 ~ 0.045%, Si2.90 ~ 3.30%, S≤0.006%, Als0.005 ~ 0.019%, N0.003 ~ 0.008%, Mn0.05 ~ 0.30%, Cu0.30 ~ 0.70%, Ni0.30 ~ 0.70%, Cr0.30 ~ 0.70%, all the other are Fe and inevitable impurity, in addition, in steel, contain B0.001 ~ 0.012%.Decarburization and nitriding are carried out simultaneously, nitriding in wet atmosphere.The basis of the method is take BN as main inhibitor.

(3) the patent of Chinese Baosteel application method as described in ZL200410099080.7 and CN101768697 A is before decarburization that nitriding or decarburization and high temperature annealing two-step all need nitriding simultaneously.

By inquiry and the analysis of patent, document etc. to the domestic and international producing oriented silicon steel by heating low temperature casting blank based on nitridation process, can find: while causing in silicon strip original inhibitor to arrive 1000 ℃ of left and right of high-temperature annealing due to the mode of low temperature heating of plate blank, seem inadequate, must be supplemented by nitriding rear operation (must be before 1020 ℃ of high temperature annealings), namely increased (Al, Si) N novel inhibitors.But the process of nitriding can not have impact to the formation reaction of Magnesium Silicate q-agent bottom again, it is simple can guarantee the stable and even of nitriding that the process of nitriding is wanted, and everything is all to guarantee that cold-rolled orientation silicon steel has the primary condition of good magnetic and surperficial Magnesium Silicate q-agent bottom, the present invention solves these problems preferably.

Summary of the invention

Have owing to producing general cold-rolled orientation silicon steel technology with high temperature heating of plate blank that energy consumption is high, spillage of material is high, Edge of Steel Strip splits greatly, productivity is bad and high in cost of production inherent defect, low temperature slab heating technique is produced general cold-rolled orientation silicon steel and can be addressed these problems preferably, thereby has powerful exploitation power.From current disclosed patent documentation and relevant technical information produce general cold-rolled orientation silicon steel by low temperature slab heating technique, be nearly all based upon on nitridation process basis.

The object of the present invention is to provide the general oriented steel raw material of a kind of use to manufacture the production method of the high grade cold rolling oriented silicon steel of 27Q105, by carrying out Hot Rolled Plate Normalizing annealing process, utilize the special time period nitriding before slab final magnetic behavior in the time of high temperature annealing forms, (the Al more strengthening under normal circumstances to form enough ratios, Si) N is favourable is mingled with, utilize its restraining effect to primary recrystallization crystal grain, impel growing up of secondary recrystallization Gauss crystal grain, grow with perfect, be conducive to obtain good finished product magnetic (this is highly beneficial to improving the trade mark) and good Magnesium Silicate q-agent bottom.Overcome in other patent and used the detrimentally affect of ammonia nitriding to Magnesium Silicate q-agent bottom, overcome in decarburizing annealing and this two-step of high temperature annealing simultaneously and all needed nitriding to bring being difficult in operation and in nitriding amount to control.

1, in order to achieve the above object, the technical solution adopted in the present invention is: the general oriented steel raw material of a kind of use is manufactured the production method of high magnetic sensing cold milling oriented silicon steel, comprises the steps:

(1), smelt

With converter or Electric furnace steel making, molten steel is carried out to vacuum-treat, composition refining and Alloying Treatment, then continuous casting becomes slab, its basic chemical composition is by weight percentage: Si is 2.5～5.0%, C is 0.01～0.10%, Mn is 0.02～0.10%, S is 0.01～0.05%, Als is 0.01～0.05%, N is 0.003～0.015%, containing Cu;

(2), hot rolling

Before slab hot rolling, in silicon steel special heating furnace, be heated to the temperature of 1150～1250 ℃, and carry out the insulation of 20～50 minutes, the abundant solid solution of favourable inclusion, to separate out Second Phase Particles tiny, disperse in silicon steel matrix in course of hot rolling subsequently, Second Phase Particles is inhibitor;

Directional silicon steel slab adopts low temperature heating of plate blank, and the Heating temperature of directional silicon steel slab obtains hot-rolled sheet at 1150～1250 ℃, and the amount of inhibitor is effectively supplemented by oozing N in rear operation;

(3), normalizing adds pickling

Hot Rolled Plate Normalizing is annealed and is carried out pickling, removes the iron scale of steel strip surface; Normalizing annealing temperature: 1050～1185 ℃, the normalizing annealing time is 1-20s, then be that 850-980 ℃ of normalizing annealings, normalizing annealing time are 30-180s in temperature, carries out cooling, speed of cooling: 60 ℃/s～10 ℃/s after normalizing annealing; Acid washing conditions: pickling in the hydrochloric acid soln that is 3～8wt% in concentration;

(4), cold rolling

Directly roll finished product thickness from hot-rolled sheet thickness by cold-rolling practice once or twice, cold rolling draft reaches 60～85%, heavy reduction rate significantly increases the dislocation desity in steel band interior tissue, the a large amount of dislocations and the goss texture that produce, be conducive to the forming core of Gauss's nucleus, Gauss's nucleus develops into perfect secondary recrystallization;

(5), decarburizing annealing

Carry out decarburizing annealing and the annealing separating agent of coating take magnesium oxide as main component to rolling the silicon strip of finished product thickness, decarburization temperature controlling range: 750～890 ℃, protective atmosphere is hydrogen, nitrogen mixture gas, in hydrogen, nitrogen mixture gas, H2 content accounts for 15～80wt%, 25～75 ℃ of protective atmosphere dew points; Decarburization time: 90～350 seconds, and the carbon in steel plate is taken off below 27ppm; The de-total oxygen of steel strip surface [O]: 155/t≤[O]≤330/t, t is steel band actual (real) thickness mm;

The annealing separating agent of described coating take magnesium oxide as main component comprises MgO, B and TiO ₂, be wherein added with 0.01 ~ 0.10% the B that accounts for annealing separating agent quality, account for the TiO of 0.01-0.30%wt of annealing separating agent quality ₂, and account for the Bi of the 0-0.2% of annealing separating agent quality,

(6), high temperature annealing

Adopt the low temperature insulation of two steps and only have the soak of a step to purify steel in high temperature annealing operation, the low temperature of first step in the low temperature insulation of two steps is incubated at 500～650 ℃, the low temperature of second step is incubated at 660～750 ℃, adopts pure N at the low temperature holding stage of second step with in being warmed up to the process before 980～1090 ℃ in stove ₂gas is made shielding gas, and steel band is carried out to nitriding, and the dew point of logical people's purity nitrogen requires≤and-60 ℃, the dew point of furnace atmosphere requires≤30 ℃; The temperature range of the soak of a step is 1150～1230 ℃;

(7), stretching and leveling annealing

Stretching and leveling annealing process routinely carries out.

Specifically, the general oriented steel raw material of use of the present invention is manufactured the production method of the high trade mark high magnetic sensing cold milling of 27Q105 oriented silicon steel, comprises the steps:

(1), smelt

Make steel with converter (or electric furnace), molten steel is carried out to vacuum-treat, composition refining and Alloying Treatment, then continuous casting becomes slab, its basic chemical composition is: Si(2.5～5.0), C(0.01～0.10), Mn(0.02～0.10), S(0.01～0.05), Als(0.01～0.05), N(0.003～0.015), some composition systems also contain Mo, Sb, Cr, etc. one or more in element, all the other are iron and inevitable impurity element, and this product is generally containing Cu;

(2), hot rolling

Before slab hot rolling, in silicon steel special heating furnace, be heated to the temperature of 1150～1250 ℃ of left and right, and carry out above insulation in 15～60 minutes, make the abundant solid solution of favourable inclusion, to separate out Second Phase Particles tiny, disperse in silicon steel matrix in course of hot rolling subsequently---be inhibitor;

Adopt low temperature heating of plate blank, the Heating temperature of directional silicon steel slab is 1150～1250 ℃ of left and right, and to be that hot rolled coil is boundless split its advantage, and productivity is good, process furnace long service life, and silicon steel lumber recovery is high; Its shortcoming is that favourable to be mingled with solid solution abundant not, and the amount of inhibitor is effectively supplemented by oozing N in rear operation;

(3), normalizing adds pickling

Hot Rolled Plate Normalizing is annealed and is carried out pickling, removes the iron scale of steel strip surface; Normalizing annealing temperature: 1050～1185 ℃ of (1～20s)+850～980 ℃ (30～180s), speed of cooling: 60 ℃/s～10 ℃/s; Acid washing conditions: pickling in the hydrochloric acid soln of 5% left and right;

(4), cold rolling

Directly roll finished product thickness from hot-rolled sheet thickness by (or twice) cold-rolling practice once, cold rolling draft is 60～85%.Heavy reduction rate significantly increases the dislocation desity in steel band interior tissue, the a large amount of dislocations and the goss texture that produce, be conducive to the forming core of Gauss's nucleus, as long as there are enough favourable existence that is mingled with in the time that high temperature annealing operation secondary recrystallization occurs, these Gauss's nucleus just can develop into perfect secondary recrystallization;

(5), decarburizing annealing

Carry out decarburizing annealing and the annealing separating agent of coating take magnesium oxide as main component to rolling the silicon strip of finished product thickness, decarburization temperature controlling range: 750～890 ℃, protective atmosphere is hydrogen, nitrogen mixture gas, and H2 content accounts for 15～80%, 25～75 ℃ of protective atmosphere dew points; Decarburization time: 90～350 seconds, and the carbon in steel plate is taken off to the level of finished product magnetic that do not affect (generally should below 30ppm); The de-total oxygen of steel strip surface [O]: 155/t≤[O]≤330/t(t is steel band actual (real) thickness mm);

(6), high temperature annealing

(first is at 550～650 ℃ to adopt two steps in high temperature annealing operation, second at 660～750 ℃) low temperature insulation and only have the soak (purification steel) of a step, in stove, adopt pure N at the low temperature holding stage of second step with in being warmed up to the process before 980～1090 ℃ ₂gas is made shielding gas, and steel band is carried out to nitriding, and the dew point of logical people's purity nitrogen requires≤and-60 ℃, the dew point of furnace atmosphere requires≤30 ℃;

In high-temperature annealing process, occur successively: MgSiO ₄the formation reaction (magnesium oxide of coating and the silicon dioxde reaction of surface of steel plate generate) of bottom, generation, growth and the growth of secondary recrystallization, (this stage is the final stage in high-temperature annealing process part to purify steel, element except iron and silicon in silicon steel is removed totally as much as possible, be included in oriented silicon steel production process above as favourable be mingled with protected and before secondary recrystallization occurs as the composition such as N, S of inhibitor integral part) physical-chemical reaction, obtain the cold-rolled orientation silicon steel that orientation degree is high, iron loss is low;

(7), stretching and leveling annealing

Stretching and leveling annealing process routinely carries out and obtains high magnetic strength (the high trade mark of 27Q105) cold-rolled orientation silicon steel.

The remarkable advantage of the inventive method:

, adopt low temperature heating of plate blank, the Heating temperature of directional silicon steel slab is 1150～1250 ℃ of left and right, to be that hot rolled coil is boundless split its advantage, productivity is good, process furnace long service life, silicon steel lumber recovery is high; Meanwhile the amount of inhibitor need to supplement to strengthen inhibition ability by oozing N in rear operation, improves secondary recrystallization, improves magnetic, improves the trade mark;

(2), roll finished product thickness by (or twice) cold-rolling practice once from hot-rolled sheet thickness, heavy reduction rate significantly increases the dislocation desity in steel band interior tissue, a large amount of dislocations that produce and be conducive to the formation of goss texture, be conducive to the forming core of Gauss's nucleus, in the time that occurring, high temperature annealing operation secondary recrystallization has enough favourable existence that is mingled with, this just can develop into perfect (110) [001] secondary recrystallization tissue, and its direct effect improves exactly magnetic, improves trade mark rank;

(3) (first is at 550～650 ℃, to adopt two steps in high temperature annealing operation, second at 660～750 ℃) low temperature insulation and the soak (purification steel) of a step, the low temperature holding stage of second step be warmed up to the process before 980～1090 ℃ in adopt pure N in stove ₂gas is made shielding gas, and steel band is carried out to nitriding, and the dew point of logical people's purity nitrogen requires≤and-60 ℃, the dew point of furnace atmosphere requires≤30 ℃;

(4), the object of now nitriding is the amount that increases inhibitor, make to have in steel band sufficient amount favourable be mingled with to protect be about to or ongoing secondary recrystallization completes smoothly and grows perfect, inhibitor just forms in the time of steel-making, in hot rolling and change form and lose in each operation subsequently, need suitably to supplement, this moment nitriding role strengthens inhibitor (Al, Si) N etc. exactly, so that improve secondary recrystallization;

(5), the feature of nitriding is here directly to ooze with purity nitrogen, not to carry out nitriding (having avoided the many disadvantageous effects with ammonia nitriding) with ammonia, under the prerequisite of total annealing cycle of control, increase a low temperature insulation step in the high temperature annealing stage, i.e. second low holding stage and 980～1090 ℃ of logical purity nitrogen nitridings of temperature rise period composition before, this role of respective stage still played high temperature annealing in nitriding time; The nitriding here neither carry out nitriding with hydrogen, nitrogen mixture gas as the patent Introduction having, but with purity nitrogen, neither, in decarburizing annealing and high temperature annealing nitriding simultaneously, only carry out early stage at high temperature annealing.Opportunity, the nitriding amount etc. of nitriding is all only for an object---strengthen and strengthen inhibitor in secondary recrystallization stage performance effect fully, so in advance little in operation nitriding role above.After secondary recrystallization body completes, the historic mission of inhibitor also just completes, and now its effect in oriented silicon steel is from changing into harmful being mingled with original favourable being mingled with.Because in oriented silicon steel finished product, except iron and silicon, other elements all have inhibition to magnetic history more or less in existence, so unfavorable to the magnetic of material.And in oriented silicon steel, to have the elements such as a certain amount of carbon, manganese, sulphur, aluminium in steel-making, this is the needs for middle Working Procedure Controlling---its object only has one: develop and improve secondary recrystallization---, and this is that cold-rolled orientation silicon steel is peculiar, is also the reason that present method can be manufactured with general oriented steel raw material the high grade cold rolling oriented silicon steel of 27Q105.

Embodiment

The general oriented steel raw material of a kind of use of the present invention is manufactured the production method of high magnetic sensing cold milling oriented silicon steel, comprises the steps:

(1) smelt

With converter or Electric furnace steel making, molten steel is carried out to vacuum-treat, composition refining and Alloying Treatment, then continuous casting becomes slab, its basic chemical composition is by weight percentage: Si is 2.5～5.0%, C is 0.01～0.10%, Mn is 0.02～0.10%, S is 0.01～0.05%, Als is 0.01～0.05%, N is 0.003～0.015%, containing Cu; , all the other are iron and impurity; When concrete enforcement, its experimental steel steel-making composition is pressed the table 1 of embodiment mono-;

(2) hot rolling

Before slab hot rolling, in silicon steel special heating furnace, be heated to the temperature of 1150～1250 ℃, and carry out the insulation of 20～50 minutes, the abundant solid solution of favourable inclusion, to separate out Second Phase Particles tiny, disperse in silicon steel matrix in course of hot rolling subsequently, Second Phase Particles is inhibitor;

Directional silicon steel slab adopts low temperature heating of plate blank, the Heating temperature of directional silicon steel slab obtains hot-rolled sheets (while specifically enforcement its specific experiment data as: Heating temperature, finishing temperature etc. refers to table 2) at 1150～1250 ℃, and the amount of inhibitor is effectively supplemented by oozing N in rear operation;

(3) normalizing adds pickling

Hot Rolled Plate Normalizing is annealed and is carried out pickling, removes the iron scale of steel strip surface; Normalizing annealing temperature: 1050～1185 ℃, the normalizing annealing time is 1-20s, then be that 850-980 ℃ of normalizing annealings, normalizing annealing time are 30-180s in temperature, carries out cooling, speed of cooling: 60 ℃/s～10 ℃/s after normalizing annealing; Acid washing conditions: pickling in the hydrochloric acid soln that is 3～8wt% in concentration; Acid washing conditions in following embodiment is: pickling in the hydrochloric acid soln that is 5wt% in concentration.(while specifically enforcement, its specific experiment data are shown in described in the step 2 of following embodiment mono-)

(4) cold rolling

Directly roll finished product thickness from hot-rolled sheet thickness by cold-rolling practice once or twice, the cold rolling draft that cold rolling draft reaches in the following embodiment of 60～85%(reaches 80%), heavy reduction rate significantly increases the dislocation desity in steel band interior tissue, the a large amount of dislocations and the goss texture that produce, be conducive to the forming core of Gauss's nucleus, Gauss's nucleus develops into perfect secondary recrystallization;

(5) decarburizing annealing

Carry out decarburizing annealing and the annealing separating agent of coating take magnesium oxide as main component to rolling the silicon strip of finished product thickness, decarburization temperature controlling range: 750～890 ℃ (800 ℃ of decarburization temperature in following embodiment), protective atmosphere is hydrogen, nitrogen mixture gas, in hydrogen, nitrogen mixture gas, H2 content accounts for H2 content in hydrogen in the following embodiment of 15～80wt%(, nitrogen mixture gas and accounts for 30wt%), 25～75 ℃ of protective atmosphere dew points; Decarburization time: 90～350 seconds (decarburization time in following embodiment is 200 seconds), and the carbon in steel plate is taken off below 27ppm; The de-total oxygen of steel strip surface [O]: 155/t≤[O]≤330/t, t is steel band actual (real) thickness mm; Concrete implementation data is in table 4.

The annealing separating agent of described coating take magnesium oxide as main component comprises MgO, B and TiO ₂, be wherein added with 0.01 ~ 0.10% the B that accounts for annealing separating agent quality, account for the TiO of 0.01-0.30%wt of annealing separating agent quality ₂, and account for the Bi of the 0-0.2% of annealing separating agent quality, while specifically enforcement, concrete additive and content are shown in the table 3-1 of following embodiment.

(6) high temperature annealing

Adopt the low temperature insulation of two steps and only have the soak of a step to purify steel in high temperature annealing operation, the low temperature of first step in the low temperature insulation of two steps is incubated at 500～650 ℃, the low temperature of second step is incubated at 660～750 ℃, adopts pure N at the low temperature holding stage of second step with in being warmed up to the process before 980～1090 ℃ in stove ₂gas is made shielding gas, and steel band is carried out to nitriding, and the dew point of logical people's purity nitrogen requires≤and-60 ℃, the dew point of furnace atmosphere requires≤30 ℃; The temperature range of the soak of a step is (1150～1230 ℃); (while specifically enforcement, its concrete data are in table 4)

(7) stretching and leveling annealing

Stretching and leveling annealing process routinely carries out.

Following embodiment all tests by above-described step (1)-(7), and step is tested by step (1)-(7), and specific experiment data are tested by described particular contents such as following tables.

embodiment mono-:

1, with 500 kilograms of vacuum ovens according to the ultimate constituent steel-making of table 1, and hot-rolled condition is as table 2:

Table 1, experimental steel steel-making composition (wt%)

Composition	C	Si	Mn	P	S	Als	N	Sn	Remarks
										A	0.059	3.15	0.15	0.021	0.015	0.025	0.048	0.018	?
B	0.048	3.09	0.16	0.019	0.011	0.018	0.005	0.022	?

Table 2, experimental steel hot-rolled condition (℃)

Project	Heating temperature	Finishing temperature	Coiling temperature	Thickness (mm)	Remarks
						C	1190	900	510	2.20	?
D	1295	950	535	2.20	Make comparisons

2, normalizing condition is: 1120 ℃ × 5s+900 ℃ × 60s+50 ℃/s's is cooling;

3, cold rolling band steel is to 0.30mm, carries out high temperature annealing and stretching and leveling annealing (containing being coated with insulation layer) after decarburization and coating MgO annealing separating agent, measures magnetic, and experimental result is as table 3:

Table 3, experimental result

Project	Magnetic strength B8(T)	Iron loss P17/50(w/kg)	Remarks
				AC	1．88	1．07	Example
AD	1．81	1．38	Comparative example
				BC	1．87	1．12	Example
BD	1．79	1．52	Comparative example

aC in table 3 refers to that the C in A and the table 2 in table 1 tests; AD refers to that the D in A and the table 2 in table 1 tests;bC c in B and table 2 in finger table 1 tests;bD d in B and table 2 in finger table 1 tests.

The annealing separating agent of above-mentioned coating take magnesium oxide as main component comprises MgO, B and TiO ₂, be wherein added with 0.01 ~ 0.10% the B that accounts for annealing separating agent quality, account for the TiO of 0.01-0.30%wt of annealing separating agent quality ₂, and account for the Bi of the 0-0.2% of annealing separating agent quality; Annealing separating agent take magnesium oxide as main component of the present invention be commercially available conventional " annealing separating agent take magnesium oxide as main component " (can be the patent No. as 200410099080.7 and CN101768697 A described in annealing separating agent) on basis, be added with and " account for 0.01 ~ 0.10% B of annealing separating agent quality, account for the TiO of 0.01-0.30%wt of annealing separating agent quality ₂, and account for the Bi of the 0-0.2% of annealing separating agent quality ", concrete data are in Table 3-1.

In table 3-1, double centner MgO annealing separating agent, add the relation of different elements and silicon strip magnetic and surperficial Magnesium Silicate q-agent bottom interlamination resistance value

embodiment bis-:

Carry out the nitriding experiment in early stage in high temperature annealing stage with the C hot-rolled condition steel in A composition and table 2 in the middle of above-mentioned table 1; through normalizing annealing, cold rolling, decarburizing annealing, in the time of high temperature annealing stage low insulation, the dew point of the soaking time of second step, atmosphere is as shown in table 4 on the impact of magnetic.

The relation of table 4, atmosphere, time and dew point and magnetic

The production method of general oriented silicon steel is all the mode that adopts slab heat for a long time, slab heating temperature is up to 1400 ℃ of left and right, make the favourable abundant solid solution that is mingled with, and in course of hot rolling, obtain favourable disperse distribution and the reasonable size being mingled with, in the time of high temperature annealing, suppress primary recrystallization crystal grain, obtain reasonable secondary recrystallization tissue, and can only produce 30Q120～30Q140, the cold-rolled orientation silicon steel of 27Q130～27Q 140 trades mark.(1), must have special high-temperature heater the shortcoming of this production method is:, due to heat, steel slab surface slag is serious, and process furnace is easily damaged, and maintenance cost is high, operating rate is low;

, in order to make heating of plate blank even, must long-time heating, energy consumption is high;

, due to the column crystal prosperity in slab, crystal boundary is oxidizable, causes limit to be split seriously, makes rear operation productivity poor, lumber recovery is low, production cost is high.

Method of the present invention has solved the problems referred to above effectively, use same raw material, can produce the higher trade mark and have the cold-rolled orientation silicon steel of the 27Q105 trade mark by improving technique, and with Japan, the method of the states such as Korea S and compared with the method for domestic Baosteel etc., the present invention is by the dislocation desity in once (or twice) cold rolling raising steel strip substrate of heavy reduction, be conducive to the formation of goss texture, and carry out nitriding in the high temperature annealing stage by purity nitrogen, make to form in steel band (the Al of increase, Si) N, add MnS in steel band etc., what make sufficient amount is favourablely mingled with effective inhibition primary recrystallization tissue, stable to obtaining, perfect secondary recrystallization tissue also improves magnetic, improve the trade mark highly beneficial.Simultaneously present method, only in abundant nitriding in the early stage of high temperature annealing, does not adopt nitriding processing multiple operation, special, does not need nitriding device, formation to good Magnesium Silicate q-agent bottom, very favourable to the raising of oriented silicon steel finished product magnetic.

The facilities and equipments of the inventive method are the conventional equipment of producing oriented silicon steel, and enforcement technology is simple.Thereby there is good popularizing application prospect.

Claims (1)

1. a production method of manufacturing high magnetic sensing cold milling oriented silicon steel with general oriented steel raw material, comprises the steps:

(1) smelt

With converter or Electric furnace steel making, molten steel is carried out to vacuum-treat, composition refining and Alloying Treatment, then continuous casting becomes slab, its basic chemical composition is by weight percentage: Si is 2.5～5.0%, C is 0.01～0.10%, Mn is 0.02～0.10%, S is 0.01～0.05%, Als is 0.01～0.05%, N is 0.003～0.015%, containing Cu;

(2) hot rolling

Before slab hot rolling, in silicon steel special heating furnace, be heated to the temperature of 1150～1250 ℃, and carry out the insulation of 20～50 minutes, the abundant solid solution of favourable inclusion, to separate out Second Phase Particles tiny, disperse in silicon steel matrix in course of hot rolling subsequently, Second Phase Particles is inhibitor;

Directional silicon steel slab adopts low temperature heating of plate blank, and the Heating temperature of directional silicon steel slab obtains hot-rolled sheet at 1150～1250 ℃, and the amount of inhibitor is effectively supplemented by oozing N in rear operation;

(3) normalizing adds pickling

Hot Rolled Plate Normalizing is annealed and is carried out pickling, removes the iron scale of steel strip surface; Normalizing annealing temperature: 1050～1185 ℃, the normalizing annealing time is 1-20s, then be that 850-980 ℃ of normalizing annealings, normalizing annealing time are 30-180s in temperature, carries out cooling, speed of cooling: 60 ℃/s～10 ℃/s after normalizing annealing; Acid washing conditions: pickling in the hydrochloric acid soln that is 3～8wt% in concentration;

(4) cold rolling

Directly roll finished product thickness from hot-rolled sheet thickness by cold-rolling practice once or twice, cold rolling draft reaches 60～85%, heavy reduction rate significantly increases the dislocation desity in steel band interior tissue, the a large amount of dislocations and the goss texture that produce, be conducive to the forming core of Gauss's nucleus, Gauss's nucleus develops into perfect secondary recrystallization;

(5) decarburizing annealing

Carry out decarburizing annealing and the annealing separating agent of coating take magnesium oxide as main component to rolling the silicon strip of finished product thickness, decarburization temperature controlling range: 750～890 ℃, protective atmosphere is hydrogen, nitrogen mixture gas, in hydrogen, nitrogen mixture gas, H2 content accounts for 15～80wt%, 25～75 ℃ of protective atmosphere dew points; Decarburization time: 90～350 seconds, and the carbon in steel plate is taken off below 27ppm; The de-total oxygen of steel strip surface [O]: 155/t≤[O]≤330/t, t is steel band actual (real) thickness mm;

The annealing separating agent of described coating take magnesium oxide as main component comprises MgO, B and TiO ₂, be wherein added with 0.01 ~ 0.10% the B that accounts for annealing separating agent quality, account for the TiO of 0.01-0.30%wt of annealing separating agent quality ₂, and account for the Bi of the 0-0.2% of annealing separating agent quality,

(6) high temperature annealing

Adopt the low temperature insulation of two steps and only have the soak of a step to purify steel in high temperature annealing operation, the low temperature of first step in the low temperature insulation of two steps is incubated at 500～650 ℃, the low temperature of second step is incubated at 660～750 ℃, adopts pure N at the low temperature holding stage of second step with in being warmed up to the process before 980～1090 ℃ in stove ₂gas is made shielding gas, and steel band is carried out to nitriding, and the dew point of logical people's purity nitrogen requires≤and-60 ℃, the dew point of furnace atmosphere requires≤30 ℃; The temperature range of the soak of a step is 1150～1230 ℃;

(7) stretching and leveling annealing

Stretching and leveling annealing process routinely carries out.