CN101463448A - High magnetic strength non-oriented electrical steel and production method thereof - Google Patents

Abstract

The invention provides a high magnetic induction non-oriented electrical steel, which comprises the following compositions: 0.010 % of C, 0.8-2.0% of Si, 0.2-1.2% of Mn, less than or equal to 0.03% of P, less than or equal to 0.01 % of S, less than or equal to 0.002% of Als, less than or equal to 0.003 % of N, and the rest is Fe. The manufacture method of the steel comprises: 1. smelt metal, the carbon is controlled to be less than 0.010%; silicon deoxidation is used; 2. Continuous casting and retarded cooling till less than 900 DEG C; 3. Hot rolling, heating-up temperature ranges from 1200 DEG C to 1270 DEG C; soaking is less than 1200 DEG C; billet temperature ranges from 1100-1150 DEG C; the time of heat insulation reduces by 20-50 minutes; rolling starting temperature is more than or equal to 1000 DEG C; when the temperature is more than or equal to 820 DEG C, the rolling is completed; the coiling temperature is controlled to be more than or equal to 700 DEG C; 4. Cold rolling. The invention reduces normalizing working procedures of hot rolled plates, reduces the manufacture cost, improves finished goods texture, and increases the magnetic strength of products. After production boards are annealed, the magnetic strength is kept to be constant or slightly rise while the iron loss reduces.

Description

A kind of high-magnetic strength non-oriented electrical steel and production method thereof

Technical field

The present invention relates to steel-making and technical field of steel rolling, relate in particular to a kind of electrical steel and production method thereof.

Background technology

Along with the increase of air-conditioning demand, driven the demand of compressor of air conditioner with electrical steel.Reach reduction iron loss purpose owing to need carry out anneal after air-conditioning and the punching press of freezer compressor stator-rotor iron core, the electrical steel that is used for now making compressor on the market adopts and makes transformer, electrical steel that the motor iron loss is general, when punching annealing back iron loss reduces, magnetic strength also decreases, thereby magnetic permeability is reduced, increased copper loss.

Korea S Pu item company application number be 97120376.8 and Wuhan Iron and Steel Company in application number is 2 Chinese patents of 01138224.4, mentioned a kind of electromagnetic performance production method of electrical steel preferably respectively, in the steel of these 2 patented technologies, all add trace elements such as Sn, B, and needed control B/N ratio.Because constituent content is lower, add too much boron or boron generation segregation and easily become oxide compound, can the electromagnetic performance of steel be had a negative impact so on the contrary.Molten steel is constantly inhaled nitrogen from air in smelting process, and the nitrogen content instability will cause the add-on control of boron difficult, so adopt such technology production difficulty bigger.

Summary of the invention

The object of the present invention is to provide and a kind ofly can satisfy the compressor production requirement, still can keep the good electric magnetic property after the punching annealing, and the control electrical steel and the production method thereof of producing easily.

The molten steel chemical ingredients of electrical steel of the present invention is (weight percent): C≤0.010%, Si:0.8%～2.0%, Mn:0.2%～1.2%, P≤0.03%, S≤0.01%, Als≤0.002%, N≤0.003%, all the other are iron and a small amount of inclusion, are mingled with total amount≤0.03%.

The production method of electrical steel of the present invention comprises the following steps:

A) electric furnace or converter smelting, hydrogen and nitrogen obnoxious flavour in the steel removed in vacuum refinement, carbon is controlled at＜0.010%, and adopt the silicon deoxidation, avoid aluminium to add in the steel with modes such as alloys;

B) adopt die casting or continuous casting mode that molten steel is cast ingot or base, and slowly cool to＜900 ℃, make that aluminium nitride and manganese sulfide are thick separates out;

C) steel ingot or steel billet heating zone temperature are controlled at 1200～1270 ℃, soaking zone is controlled at＜and 1200 ℃, steel billet temperature is controlled at 1100～1150 ℃, soaking time few 20～50 minutes than conventional products, carry out hot rolling after temperature is even, reduce the residence time on roller-way as far as possible, reduce calorific loss, start rolling temperature 〉=1000 ℃, finish rolling for 〉=820 ℃, 〉=700 ℃ of coiling temperature controls, hot-rolled sheet thickness approaches finished product thickness less than 2.5mm as far as possible;

D) adopt tandem rolling or single chassis mode that the hot-rolled sheet once cold rolling is become finished product thickness, or adopt the secondary cold-rolling mode that has process annealing that hot-rolled sheet is rolled into finished product thickness;

E) cold-rolled steel strip through continuous annealing furnace decarburizing annealing, be coated with operations such as insulation layer and make finished product.

Add the resistivity that aluminium can improve steel in the electrical steel, reach the purpose that reduces iron loss.Can be when adding aluminium, because electrical steel is brought the nitrogen element aborning inevitably into, and nitrogen very easily forms aluminium nitride with aluminium.Discover that when the acid-soluble aluminum content in the electrical steel is 0.002%～0.015% aluminium and nitrogen form the aluminium nitride of small and dispersed, disperse is separated out in steel in the operation of rolling, has suppressed growing up of crystal grain in annealing process subsequently, has a strong impact on electromagnetic performance.When containing a certain amount of aluminium, aluminium can increase the resistivity of steel, reduces iron loss, but aluminium very easily combines with oxygen simultaneously, easily forms aluminum oxide, and electromagnetic performance is produced detrimentally affect.And, when aluminum content more for a long time continuous casting easily cause nozzle clogging, produce difficulty.The present invention adopts silicon deoxidation mode to carry out deoxidation for reducing the amount of nitrogen in steel aluminium on the one hand, with strictness control aluminium content, reduces the influence of remaining aluminium in the steel; Adopt vacuum refinement on the other hand, the nitrogen content in the strict control steel.

For avoiding the performance fluctuation occurring in the production, difficulty is smelted in reduction, and the present invention does not add Sn and B element by the harmful element scope in the control steel thereby reach, the purpose of the non-oriented electrical steel that the suitable compressor iron loss of production is used.

The present invention reduces the aluminium nitride solid solution capacity by reducing the hot rolling Heating temperature, improves the hot rolling reeling temperature, reduces hot-rolled sheet thickness, reduces cold rolling draft.Because solid solution has aluminium nitride lower in steel, does not have oversaturated aluminium nitride to separate out in annealing process, so the product magnetic strength of producing also may increase.

Do not add aluminium in the steel of the present invention, adopt the silicon deoxidation, reduced the solid solution capacity of aluminium nitride, also avoided having reduced the formation of alumina inclusion because of aluminaization causes wadding mouth of a river problem; Improve the hot rolling reeling temperature, reduced hot-rolled sheet normalizing operation, reduced production cost; Reduce hot-rolled sheet thickness, improved finished product texture, improved the product magnetic induction, production board punching annealing back keeps magnetic strength not fall, or slightly raises when iron loss reduces.

The present invention is further described by the following embodiment.

Embodiment

Embodiment 1

Molten steel chemical ingredients: C:0.003%, Si:1.35%, Mn:0.35%, P:0.012%, S:0.003%, Als≤0.001%, N:0.0024%, all the other are iron and a small amount of inclusion.

Production method:

A) converter smelting, the RH vacuum refinement is handled, and carbon is reduced to 0.003%, adopts the silicon deoxidation, avoids aluminium to add in the steel with modes such as alloys;

B) adopt the continuous casting mode that molten steel is cast the 230mm steel billet, and make steel billet slowly cool to 850 ℃;

C) hot rolling, steel billet heating zone temperature is controlled at 1220 ℃, 1180 ℃ of soaking zone temperature, 1120 ℃ of steel billet temperatures are incubated 1 hour.Start rolling temperature is controlled at 1015 ℃, 860 ℃ finish rolling, 720 ℃ of coiling temperatures.Hot-rolled sheet thickness 2.0mm;

D) cold rolling, adopt the tandem rolling mode that hot-rolled sheet once is rolled into finished product thickness;

E) cold rolling back steel band through the decarburizing annealing of continuous annealing furnace wet hydrogen, be coated with operation such as insulation layer and make finished product.The iron loss and the magnetic induction performance of product see Table 1.

Embodiment 2

Molten steel chemical ingredients: C:0.002%, Si:0.85%, Mn:0.55%, P:0.010%, S:0.004%, Als≤0.001%, N:0.0014%, all the other are iron and a small amount of inclusion.

Production method:

A) converter smelting, the RH vacuum refinement is handled, and carbon is reduced to 0.004%, adopts the silicon deoxidation, avoids aluminium to add in the steel with modes such as alloys;

B) adopt the continuous casting mode that molten steel is cast the 230mm steel billet, and make steel billet slowly cool to 820 ℃;

C) hot rolling, steel billet heating zone temperature is controlled at 1250 ℃, 1190 ℃ of soaking zone temperature, 1130 ℃ of steel billet temperatures are incubated 45 minutes.Start rolling temperature is controlled at 1020 ℃, 865 ℃ finish rolling, 700 ℃ of coiling temperatures, hot-rolled sheet thickness 2.3mm;

D) cold rolling, adopt the tandem rolling mode that hot-rolled sheet once is rolled into finished product thickness;

E) cold rolling back steel band through the decarburizing annealing of continuous annealing furnace wet hydrogen, be coated with operation such as insulation layer and make finished product.The iron loss and the magnetic induction performance of product see Table 1.

The iron loss and the magnetic induction performance of table 1 embodiment of the invention product

^*Comparative Examples adopts the deoxidation of conventional aluminium deoxidation mode, and aluminium content is controlled at 0.008%, 1180 ℃ of hot rolling steel billet temperature, 650 ℃ of productions of coiling temperature.

Claims (2)

1. high-magnetic strength non-oriented electrical steel, the chemical ingredients that it is characterized in that molten steel is (weight percent): C≤0.010%, Si:0.8%～2.0%, Mn:0.2%～1.2%, P≤0.03%, S≤0.01%, Als≤0.002%, N≤0.003%, all the other are iron and a small amount of inclusion, are mingled with total amount≤0.03%.

2. the production method of the described high-magnetic strength non-oriented electrical steel of claim 1 is characterized in that comprising the following steps:

A) electric furnace or converter smelting, hydrogen and nitrogen obnoxious flavour in the steel removed in vacuum refinement, carbon is controlled at＜0.010%, and adopt the silicon deoxidation;

B) adopt die casting or continuous casting mode that molten steel is cast ingot or base, and slowly cool to＜900 ℃;

C) steel ingot or steel billet heating zone temperature are controlled at 1200～1270 ℃, soaking zone is controlled at＜and 1200 ℃, steel billet temperature is controlled at 1100～1150 ℃, soaking time few 20～50 minutes than conventional products, temperature is carried out hot rolling after evenly, and start rolling temperature 〉=1000 ℃ are finished rolling for 〉=820 ℃, 〉=700 ℃ of coiling temperature controls, hot-rolled sheet thickness is less than 2.5mm;

D) adopt tandem rolling or single chassis mode that the hot-rolled sheet once cold rolling is become finished product thickness, or adopt the secondary cold-rolling mode that has process annealing that hot-rolled sheet is rolled into finished product thickness;

E) cold-rolled steel strip through continuous annealing furnace decarburizing annealing, be coated with operations such as insulation layer and make finished product.