CN105177444A - Normalizing control method for producing low-temperature high-magnetic-induction oriented silicon steel - Google Patents

Abstract

The invention provides a normalizing control method for producing low-temperature high-magnetic-induction oriented silicon steel. The method comprises the steps that the components of the applicable steel comprise, by weight, 3.0%-3.35% of Si, 0.045%-0.065% of C, 0.0220%-0.0320% of Als, 0.080%-0.090% of Mn, 0.005%-0.010% of S, 0.006%-0.010% of N, 0.014%-0.015% of Cu, 0.040%-0.042% of Sn and less than 0.25% of Cr and Ni; smelting and continuous casting are performed on the steel to form a blank; two-stage normalizing is performed after hot rolling is performed; a P1.1/50 value of the steel plate is detected, and whether the value is larger than or equal to alpha and smaller than or equal to beta is judged; timing rolling is performed; decarburizing annealing and nitriding annealing are performed; the subsequent procedures such as magnesium oxide annealing separant coating are performed. According to the normalizing control method, normalizing temperature setting is performed through the relation between the iron loss value P1.1/50 of the low-temperature Hi-B steel normalizing plate and the temperature of the normalizing thermal treatment high-temperature-section steel plate to enable the P1.1/50 value of Als normalizing coils to be controlled within a needed P1.1/50 range, and therefore the product with the good magnetism is obtained.

Description

A kind of normalizing control method of producing low temperature high magnetic induction grain-oriented silicon steel

Technical field

The present invention relates to a kind of method of producing high magnetic induction grain-oriented silicon steel, belong to a kind of normalizing control method of producing low temperature high magnetic induction grain-oriented silicon steel particularly.

Background technology

Grain-oriented Si steel sheet is a kind of important alloy magnetic material, industrially utilizes the excellent magnetization property that its rolling direction possesses to prepare transformer core.And weigh magnetic property of oriented silicon steel and mainly contain following two significant parameters: under certain magnetic field intensity T condition, the magnetic induction B that siliconized plate possesses detected _t(unit T), and the iron loss P of excitation process under certain frequency and certain magnetic induction _t(unit W/Kg).In order to obtain higher magnetic induction and lower iron loss, oriented silicon steel must obtain good secondary recrystallization tissue after high temperature annealing operation, namely possess good bit to Gauss's orientation and crystal { 110} face is parallel to rolled surface, <001> is parallel to and rolls to, and suitable finished product grain size.At present, measured under 800A/m field intensity according to oriented silicon steel magnetic strength B ₈₀₀product is divided into two classes: B ₈₀₀at below 1.890T, be referred to as general oriented silicon steel (CGO); B ₈₀₀reach 1.890T and above be called high magnetic induction grain-oriented silicon steel (Hi-B or HGO).

In prior art, the production method of low temperature Hi-B oriented silicon steel mainly contains that high temperature slab heating temperature (higher than 1350 DEG C) prepares Hi-B steel method, middle temperature slab heating temperature (between 1200 DEG C to 1350 DEG C) prepares Hi-B steel method and low temperature slab heating temperature (less than 1200 DEG C) prepares Hi-B steel method.

High temperature HiB steel adopts traditional inhibitor method, be in coil of strip the precipitated phase such as MnS, AlN as inhibitor to produce the method for Hi-B steel.High temperature Hi-B steel carbon content is 0.04 ~ 0.08%, and higher carbon content ensure that in course of hot rolling to possess certain γ Phase Proportion; In high temperature Hi-B steel, the congenital inhibitor such as MnS, AlN is at γ phase solid solution large percentage, can control the uniform and stable precipitation of inhibitor in hot-rolled sheet through hot-rolled temperature, roller repairing and oiler temperature control.The preparation of normalizing process to high temperature HiB steel is most important.From metallographic change, recrystal grain comparatively hot-rolled sheet showed increased after normalizing, but normalizing process texture development is very little, and main GOSS nucleus will be preserved.The Main Function of normalizing operation is that precipitated phase obtains again back dissolving and precipitation; its mechanism of action makes AlN, MnS in hot-rolled sheet be that main inhibitor particle is incubated disperse educt through slow cooling after heat back dissolving, quicker water quick cooling of crossing prevents from separating out this kind of particle growth.Inhibitor density after normalizing increases, and possesses stronger rejection ability, all will play an important role in primary recrystallization and secondary recrystallization abnormal growth process.

And low temperature Hi-B steel method, abandoned various shortcoming heat must being taked to bring using MnS as inhibitor, adopt lower Heating temperature just can the AlN of solid solution as inhibitor.Play suitable restraining effect for reducing solid solubility temperature and growing up to primary recrystallization during decarburizing annealing, Al and N in low temperature Hi-B steel strand must take strict Composition Control.And the inherent inhibitor of low temperature Hi-B method through smelting casting and obtaining is inadequate to rejection ability in the final high temperature annealing of coil of strip, secondary recrystallization abnormal growth not exclusively, also can need after decarburizing annealing, carry out nitrogen pick-up process and forms new inhibitor to strengthen the rejection ability of AlN in high-temperature annealing process.Therefore; although the normalizing annealing effect of low temperature Hi-B steel is also the control of separating out inhibitor; but the mainly precipitation of control AlN class inhibitor; and the Main Function of this kind of inhibitor strengthens the control to primary recrystallization grain growth during decarburizing annealing, thus ensure the motivating force in secondary recrystallization abnormal growth.

In actual normalizing production process, hot rolling raw material is not unalterable.Control steel-making and hot rolling technology even if strict, all there is inevitable difference in Product Status between different heat, between the different casting blank order of same heat and between hot rolling batch.When fluctuation after can not produce considerable influence to end properties in the acceptable normal range of technique, but degree of fluctuation exceeds normal range can affect quality product.The abnormal volume of front operation is produced after the operation that existing normalizing, cold rolling, decarburization, nitriding, high temperature annealing etc. are longer, cannot obtain the HiB product that performance conforms to.Both reduced the final Hi-B qualification rate of oriented silicon steel, and be also unfavorable for reducing the high production cost of oriented silicon steel.

The present invention is according to low temperature Hi-B steel actual production feature and a large amount of Field Production Data; under the condition that existing steel grades is constant; develop the control method that a kind of normalizing process is implemented and the detection of normalizing board status judges; control the stability of normalizing volume timely and effectively; reduce the fluctuation of finished product magnetic property, while improving orientation HiB qualification rate, reduce production cost.

Low temperature Hi-B steel production process process is rolled onto from hot rolling the product of being prepared into, and usually needs through normalizing annealing, cold rolling, decarburizing annealing, nitriding annealing, the complicated heat treatment link such as high temperature annealing and the annealing of finished product coating.Each heat treatment link is mutually adaptive, could form the crystalline structure and precipitate form that meet the requirements before final high temperature annealing, becomes to have the secondary recrystallization tissue of fine magnetic property.

Summary of the invention

The present invention is directed to the material tests of low temperature HiB steel normalizing heat treatment process that prior art exists loaded down with trivial details and consuming time longer, be difficult to, to the problem involving in row and detect in time abnormal after normalizing, provide one to utilize low temperature Hi-B steel normalizing plate core loss value P _1.1/50and the relation between the final magnetic property of product defines the best P that normalizing under different al s content is rolled up _1.1/50scope, and according to normalizing plate core loss value P _1.1/50and contacting between normalizing thermal treatment high temperature section temperature carries out the control of normalizing temperature process, make steel plate P after normalizing _1.1/50value can control in optimum range, thus realizes the rational Match of normalizing process and steel grades, stably produces the normalizing control method of the low temperature high magnetic induction grain-oriented silicon steel of excellent magnetic.

Realize the concrete measure of above-mentioned purpose:

Produce a normalizing control method for low temperature high magnetic induction grain-oriented silicon steel, its step:

1) be suitable for the component of steel and weight percent content is: Si:3.00 ~ 3.35%, C:0.045 ~ 0.065%, Als:0.0220 ~ 0.0320%, Mn:0.080 ~ 0.090%, S:0.005 ~ 0.010%, N:0.006 ~ 0.010%, Cu:0.014 ~ 0.015%, Sn:0.040 ~ 0.042%, Cr and Ni total content are less than 0.25%, and all the other are Fe and inevitable inclusion;

2) smelt also continuous casting according to mentioned component and become base post-heating, Heating temperature is at 1150 ~ 1250 DEG C;

3) after conventional hot rolling, two-part normalizing annealing is carried out: first paragraph normalizing steel billet temperature T controls according to Als content in hot rolled coil, and is incubated 20 ~ 30S; Then reduce steel billet temperature to 890 ~ 910 DEG C to start to carry out second segment normalizing, and be incubated 100 ~ 120s;

Wherein the span of control of normalizing first paragraph steel billet temperature T controls according to following experimental formula:

1182.1-0.400×10 ⁶×[Als]≤T≤1237.9-0.495×10 ⁶×[Als]

In above formula: steel plate observed temperature in the annealing furnace shown by T-expression thermopair, unit is DEG C;

In Als-expression steel plate, the content of Als, is multiplied by pure decimal value;

4) the coil of strip state after normalizing is judged: the P detecting steel plate _1.1/50value, and judge to be somebody's turn to do valuewhether at α≤P _1.1/50within the scope of≤β, wherein:

α=10.71×e ^197.5×[Als]+1.35×D-14×[Si]+0.055；

β=10.95×e ^158.1×[Als]+1.35×D-14×[Si]+0.055；

In formula: the content of Als in Als-expression steel plate, substitute into by pure decimal value in formula and calculate;

The content of Si in Si-expression steel plate, substitutes into by pure decimal value in formula and calculates;

The thickness of D-expression institute normalizing plate, unit is: mm;

If P _1.1/50at α≤P _1.1/50within the scope of≤β, then show P _1.1/50meet the demands, proceed rear operation; If P _1.1/50be less than α or P _1.1/50be greater than β, then P be described _1.1/50abnormal;

5) at 150 ~ 220 DEG C, timeliness is rolling to finished product thickness;

6) carry out decarburizing annealing, and control C content at below 10ppm; Carry out nitriding annealing again, control final N content 140-300ppm;

7) routine carries out coating magnesium oxide annealing separating agent, final high temperature annealing; Rear operation such as coating tensile coating, stretching and leveling etc.

The present invention is by the P corresponding to excellent magnetic product according to different al s _1.1/50scope, adopts P in normalizing operation _1.1/50=e ^{(2.86-0.000395 × T)}the experimental formula of+1.35 × D--14 × [Si]+0.055 carries out the control of normalizing process temperature, makes normalizing roll up P _1.1/50value, within zone of reasonableness, detects the P of normalizing plate after normalizing _1.1/50it is whether normal that value just can determine rapidly normalizing volume; thus take corresponding restriction; the exception that will produce substandard product is rolled up and send production under limit; unacceptable product is eliminated in early stage instead of after whole process cycle completes; the HiB qualification rate of finished product is improved, and corresponding cost consumption is minimized.

Compared with prior art, it utilizes low temperature Hi-B steel normalizing plate core loss value P in the present invention _1.1/50and contacting between normalizing thermal treatment high temperature section steel billet temperature carries out the setting of normalizing temperature, makes the P that different al s normalizing is rolled up _1.1/50value controls the P needed for magnetic qualified product _1.1/50in scope, thus obtain the product of excellent magnetic, realize the rational Match of normalizing process and steel grades, control the waste of abnormal normalizing product and produce, reach the object of the excellent product of stably manufactured.

Embodiment

Below the present invention is described in detail:

Table 1 is the main technologic parameters list of various embodiments of the present invention and comparative example;

Table 2 is each embodiment of invention and comparative example material parameter, the average magnetic of finished product and the list of HiB qualification rate;

The composition of the low temperature high magnetic induction grain-oriented silicon steel that various embodiments of the present invention are produced is all in following composition and content range (in wt%) value:

Si:3.00 ~ 3.35%, C:0.045 ~ 0.065%, Als:0.0220 ~ 0.0320%, Mn:0.080 ~ 0.090%, S:0.005 ~ 0.010%, N:0.006 ~ 0.010%, Cu:0.014 ~ 0.015%, Sn:0.040 ~ 0.042%, Cr and Ni total content are less than 0.25%, and all the other are Fe and inevitable inclusion.

Various embodiments of the present invention are produced according to following steps:

Produce a normalizing control method for low temperature high magnetic induction grain-oriented silicon steel, its step:

1) be suitable for the component of steel and weight percent content is: Si:3.00 ~ 3.35%, C:0.045 ~ 0.065%, Als:0.0220 ~ 0.0320%, Mn:0.080 ~ 0.090%, S:0.005 ~ 0.010%, N:0.006 ~ 0.010%, Cu:0.014 ~ 0.015%, Sn:0.040 ~ 0.042%, Cr and Ni total content are less than 0.25%, and all the other are Fe and inevitable inclusion;

2) smelt also continuous casting according to mentioned component and become base post-heating, Heating temperature is at 1150 ~ 1250 DEG C;

3) after conventional hot rolling, two-part normalizing annealing is carried out: first paragraph normalizing steel billet temperature T controls according to Als content in hot rolled coil, and is incubated 20 ~ 30S; Then reduce steel billet temperature to 890 ~ 910 DEG C to start to carry out second segment normalizing, and be incubated 100 ~ 120s;

Wherein the span of control of normalizing first paragraph steel billet temperature T controls according to following experimental formula:

1182.1-0.400×10 ⁶×[Als]≤T≤1237.9-0.495×10 ⁶×[Als]

In above formula: steel plate observed temperature in the annealing furnace shown by T-expression thermopair, unit is DEG C;

In Als-expression steel plate, the content of Als, is multiplied by pure decimal value;

4) the coil of strip state after normalizing is judged: the P detecting steel plate _1.1/50value, and judge to be somebody's turn to do valuewhether at α≤P _1.1/50within the scope of≤β, wherein:

α=10.71×e ^197.5×[Als]+1.35×D-14×[Si]+0.055；

β=10.95×e ^158.1×[Als]+1.35×D-14×[Si]+0.055；

In formula: the content of Als in Als-expression steel plate, substitute into by pure decimal value in formula and calculate;

The content of Si in Si-expression steel plate, substitutes into by pure decimal value in formula and calculates;

The thickness of D-expression institute normalizing plate, unit is: mm;

If P _1.1/50at α≤P _1.1/50within the scope of≤β, then show P _1.1/50meet the demands), proceed rear operation; If P _1.1/50be less than α or P _1.1/50be greater than β, then P be described _1.1/50abnormal;

5) at 150 ~ 220 DEG C, timeliness is rolling to finished product thickness;

6) carry out decarburizing annealing, and control C content at below 10ppm; Carry out nitriding annealing again, control final N content 140-300ppm;

7) routine carries out coating magnesium oxide annealing separating agent, final high temperature annealing; Rear operation such as coating tensile coating, stretching and leveling etc.

The main technologic parameters list of table 1 various embodiments of the present invention and comparative example

Continued access table 1

Table 2 is each embodiment of invention and comparative example material parameter, the average magnetic of finished product and the list of HiB qualification rate

The method of calculation of finished product HiB qualification rate in table 2, in inspection after construction process, coil of strip magnetic strength meets B ₈₀₀the ratio of>=1.89T moiety by weight and total mass.

As can be seen from embodiment table 2, adopt the inventive method to carry out adjustment to normalizing process and control coil of strip P _1.1/50be worth in the reasonable scope, the finished product B produced ₈₀₀>=1.90T, P _1.7/50the high magnetic induction grain-oriented silicon steel of≤0.98W/kg, and overall HiB qualification rate is more than 86%.And the product magnetic property adopting usual manner to produce in comparative example is at below 1.9T, and final HiB qualification rate is overall lower than 80%.

This embodiment is only the best and exemplifies, the restricted enforcement not to technical solution of the present invention.

Claims (1)

1. produce a normalizing control method for low temperature high magnetic induction grain-oriented silicon steel, its step:

1) be suitable for the component of steel and weight percent content is: Si:3.00 ~ 3.35%, C:0.045 ~ 0.065%, Als:0.0220 ~ 0.0320%, Mn:0.080 ~ 0.090%, S:0.005 ~ 0.010%, N:0.006 ~ 0.010%, Cu:0.014 ~ 0.015%, Sn:0.040 ~ 0.042%, Cr and Ni total content are less than 0.25%, and all the other are Fe and inevitable inclusion;

2) smelt also continuous casting according to mentioned component and become base post-heating, Heating temperature is at 1150 ~ 1250 DEG C;

3) after conventional hot rolling, two-part normalizing annealing is carried out: first paragraph normalizing steel billet temperature T controls according to Als content in hot rolled coil, and is incubated 20 ~ 30S; Then reduce steel billet temperature to 890 ~ 910 DEG C to start to carry out second segment normalizing, and be incubated 100 ~ 120s;

Wherein the span of control of normalizing first paragraph steel billet temperature T controls according to following experimental formula:

1182.1-0.400×10 ⁶×[Als]≤T≤1237.9-0.495×10 ⁶×[Als]

In above formula: steel plate observed temperature in the annealing furnace shown by T-expression thermopair, unit is DEG C;

In Als-expression steel plate, the content of Als, is multiplied by pure decimal value;

4) the coil of strip state after normalizing is judged: the P detecting steel plate _1.1/50value, and judge to be somebody's turn to do valuewhether at α≤P _1.1/50within the scope of≤β, wherein:

α=10.71×e ^197.5×[Als]+1.35×D-14×[Si]+0.055；

β=10.95×e ^158.1×[Als]+1.35×D-14×[Si]+0.055；

In formula: the content of Als in Als-expression steel plate, substitute into by pure decimal value in formula and calculate;

The content of Si in Si-expression steel plate, substitutes into by pure decimal value in formula and calculates;

The thickness of D-expression institute normalizing plate, unit is: mm;

If P _1.1/50at α≤P _1.1/50within the scope of≤β, then show P _1.1/50meet the demands), proceed rear operation; If P _1.1/50be less than α or P _1.1/50be greater than β, then P be described _1.1/50abnormal;

5) at 150 ~ 220 DEG C, timeliness is rolling to finished product thickness;

6) carry out decarburizing annealing, and control C content at below 10ppm; Carry out nitriding annealing again, control final N content 140-300ppm;

7) routine carries out coating magnesium oxide annealing separating agent, final high temperature annealing; Rear operation such as coating tensile coating, stretching and leveling etc.