CN101992210B - Method for producing aluminum-free steel grade of cold milling non-oriented silicon steel - Google Patents

Abstract

The invention relates to a method for producing aluminum-free steel grade of cold milling non-oriented silicon steel, which comprises the following steps of: controlling the quantity of Als to be not more than 0.0010 percent and the content of residual elements easily forming nitrides; adopting low-temperature heating and controlled-temperature milling for hot milling; adopting primary cold method milling or secondary cold method milling with the middle annealing for cold milling; and carrying out the integrated control measures such as wet hydrogen decarburization, recrystallization temperature annealing and the like. Thereby, the mass production of efficient aluminum-free cold milling non-oriented silicon steel can be realized with low production cost under the condition of the traditional equipment, the electromagnetic performance of the efficient aluminum-free cold milling non-oriented silicon steel is superior to the cold milling non-oriented silicon steel produced by the same-trademark conventional process, the iron loss is averagely reduced by about 0.4W/kg, the magnetic strength is averagely improved by 0.2T, and the method not only meets the market requirements, but also has obvious economic benefits and social benefits.

Description

A kind of method of producing aluminum-free steel grade of cold milling non-oriented silicon steel

Technical field

The invention belongs to smelting, the processing technique field of steel, particularly a kind of by control smelting composition and rolling mill practice, the method for producing aluminum-free steel grade of cold milling non-oriented silicon steel.

Background technology

Along with the fast development of refrigeration compressor industry, not only require the cold rolling non-orientation silicon steel product to have high magnetic strength, low iron loss, and the clout recovery can be carried out the casing casting after requiring the product punching out, and the body of casting after the casting is interior without Bubble formation.Thereby new problem and the requirement of Geng Gao have been proposed for low cost, high magnetic strength, the well behaved Research and development and production without the aluminum steel kind of punching out.

There are many difficult points in process of production in aluminum-free steel grade of cold milling non-oriented silicon steel.Do not contain aluminium owing in the molten steel in the smelting process, can not be with traditional Al deoxidation, the general silicon deoxidation mode that adopts, can cause deoxidation incomplete, field trash increases, and all will strictly control so the anti-material of auxiliary material (alloying) is brought nitrogen content and the easy residual element content that forms nitride of aluminium, smelting into; Non-oriented electrical steel is without the lifting (increase of silicone content) of aluminum steel kind with the trade mark, phase reduces between the limited proportionality, in the hot rolling common process is produced, along with temperature control fuctuation within a narrow range, drag, rolling stability rapid fluctuation after the distortion, common process production controllability reduces, and often occurs the accidents such as " steel-fastening ", " heap steel " in the production, not only be difficult to guarantee the up-to-standard rate of finished product cold rolling electric, increased production cost and accident treatment expense; And have a strong impact on the stability of production, cause the decrease of lumber recovery and output.

Summary of the invention

The present invention aims to provide a kind of existing equipment that utilizes, and substitutes the normalizing unit by rational alloy designs and strict process control and produces non-orientation silicon steel without the aluminum steel kind, realizes the purpose of high efficiency, the qualified electrical sheet cold-rolled products of low-cost production.

Studies have shown that, want to avoid the accidents such as " steel-fastening ", " heap steel ", control second-phase form, during technological design was implemented, the monophase field was rolling in needs implementation low-temperature heat and the finishing stands, also needs lower final rolling temperature and higher coiling temperature to match.Heating-up temperature is low, can suppress the solid solution of the nitride particles such as ALN in the steel, thereby alleviates the degree of separating out subsequently and suppress the pinning effect of the grain boundary that crystal grain further grows up; Higher coiling temperature impels dissolved aluminum and nitrogen to separate out faster with the form of ALN, the ALN particle is increased slightly, and therefore, the pinning ability of recrystallization stage grain boundary reduces in continuous annealing operation subsequently, it is more smooth, even that crystal grain is grown, thereby obtain excellent electromagnetic performance.Lower heating-up temperature and higher coiling temperature have been facilitated soft thick institutional framework, and suppress the formation of (111) texture, are conducive to non-orientation silicon steel and produce required original texture component, play the effect of normalizing process in the efficient silicon steel production.

For this reason, the technical solution taked of the present invention is:

A kind of method of producing aluminum-free steel grade of cold milling non-oriented silicon steel is characterized in that, by smelting composition and rolling, the parameter and annealing of control steel, realizes the production of aluminum-free steel grade of cold milling non-oriented silicon steel; Its concrete control method is:

1, control comprises the residual aluminium content of bringing in deoxidized aluminium, auxiliary material and the refractory material alloying process, control Als≤0.0010%.Must strictly control the content of Al element without the aluminum steel kind, guarantee that the content with the Al element is controlled at≤0.0010%, so refinement and deoxidation technique need adopt the silicon deoxidation.

2, control the residual element content of smelting nitrogen content and easily forming nitride, the content difference≤0.0020% of control N, Ti, Nb, V.

When the residual element contents such as N, Ti, Nb, V are too high, two-phase particle size, composition and the distribution of hot rolling sample is as main take square TiN particle between a certain amount of 30～80 μ m, other has the compound S compound of S, N compound or Ti, Mn that a small amount of macroparticle is Ti, Al, Mn is compound, remains in the magnetic property that will worsen steel plate in the steel.

3, to take low-temperature heat and finish rolling to carry out temperature-controlled rolling be that the unidirectional district of ferrite is rolling in hot rolling, and control two-phase precipitation state.

A, steel billet of hot rolling when being heated temperature are 1000～1150 ℃, start rolling temperature 〉=950 ℃, finishing temperature 〉=840 ℃, curling temperature 〉=690 ℃;

B, cold rolling employing once or with the secondary cold process of intermediate annealing are rolling to finished product thickness;

C, annealing adopt bell furnace or continuous annealing furnace to carry out wet hydrogen decarburization, recrystallization temperature annealing.

Because the present invention takes rational Composition Design and control, simultaneously operation, the steps such as strand heating, hot rolling, cold rolling, annealing are carried out Whole Process Control, thereby under the existing equipment condition, with lower production cost, realized batch production efficiently without the aluminium cold rolling non-orientation silicon steel, and the product electromagnetic performance is good.Through check, its iron loss P _1.5Reach 5.02W/kg, magnetic strength B ₅₀₀₀Be 1.756T, the accidents such as steel-fastening, heap steel have not only been avoided, unnecessary quality and expenses have been reduced, and satisfied the market demand, for utilizing existing equipment production efficiently to provide a practical and effective approach without the aluminium cold rolling non-orientation silicon steel, have larger economic benefit and social benefit.

The specific embodiment

Below, the invention will be further described in conjunction with the embodiments.

Embodiment 1:

The chemical composition of steel and weight percent content are:

C 0.0015%, Si 0.573%, Mn 0.345%, P 0.0386%, S 0.0048%, Als 0.0010%, N 0.0018%, Ti 0.001%, Nb, V difference≤0.0020%.All the other are inevitable impurity.

Converter smelting is strictly controlled the residual aluminium of bringing in deoxidized aluminium, auxiliary material and the refractory material alloying process.Adopt the RH vacuum refining to process the deoxidation of refinement and deoxidation process using silicon.Adopt the continuous casting mode that molten steel is cast continuous casting billet.

Low-temperature heat is adopted in hot rolling, and billet heating temperature is 1080 ℃; Temperature-controlled rolling, 1030 ℃ of start rolling temperatures, 860 ℃ of finishing temperatures, 693 ℃ of curling temperature are carried out in finish rolling.

Cold rolling, adopt the tandem rolling mode once to be rolled into the finished strip that thickness is 0.5mm.

Annealing, is coated with the operation such as insulating barrier at the decarburizing annealing of cold rolling employing continuous annealing furnace wet hydrogen, makes without the aluminium cold rolling non-orientation silicon steel.

Embodiment 2:

The chemical composition of steel and weight percent content are:

C 0.0020%, Si 0.85%, Mn 0.44%, P 0.037%, S 0.0052%, Als 0.0005%, N 0.0010%, Ti 0.0009%, Nb, V difference≤0.0020%.All the other are inevitable impurity.

Converter smelting also adopts the RH vacuum refining to process, and the silicon deoxidation of refinement and deoxidation process using is also cast continuous casting billet.

The steel billet of hot rolling when being heated temperature is 1150 ℃; 1030 ℃ of finish rolling start rolling temperatures, 890 ℃ of finishing temperatures, 697 ℃ of curling temperature.

Cold rolling, adopt the tandem rolling mode once to be rolled into the finished strip that thickness is 0.5mm.

Annealing, is coated with the operation such as insulating barrier at the decarburizing annealing of cold rolling employing continuous annealing furnace wet hydrogen, makes without the aluminium cold rolling non-orientation silicon steel.

Embodiment 3:

The chemical composition of steel and weight percent content are:

C 0.0010%, Si 1.15%, Mn 0.62%, P 0.0274%, S 0.0037%, Als 0.0008%, N 0.0016%, Ti 0.0019%, Nb, V difference≤0.0020%.All the other are inevitable impurity.

Converter smelting also adopts the RH vacuum refining to process, and the silicon deoxidation of refinement and deoxidation process using is also cast continuous casting billet.

The steel billet of hot rolling when being heated temperature is 1100 ℃; 1010 ℃ of finish rolling start rolling temperatures, 870 ℃ of finishing temperatures, 690 ℃ of curling temperature.

Cold rolling, adopt the tandem rolling mode once to be rolled into the finished strip that thickness is 0.5mm.

Annealing, is coated with the operation such as insulating barrier at the decarburizing annealing of cold rolling employing continuous annealing furnace wet hydrogen, makes without the aluminium cold rolling non-orientation silicon steel.

The same trade mark electromagnetic performance without aluminium cold rolling non-orientation silicon steel and common process production of producing as stated above sees the following form:

As seen from the above table, by the aluminum-free steel grade of cold milling non-oriented silicon steel that the inventive method is produced, average iron loss P _1.5Be 5.02W/kg, average magnetic strength B ₅₀₀₀Be 1.756T.And the average iron loss P of the same grade cold rolling non-oriented silicon steel that common process is produced _1.5Be 5.427W/kg, average magnetic strength B ₅₀₀₀Be 1.737T.Contrast as seen, the aluminum-free steel grade of cold milling non-oriented silicon steel that the inventive method is produced has on average reduced about 0.407W/kg than the same grade cold rolling non-oriented silicon steel iron loss of common process production, and magnetic strength has on average improved 0.019T.

Claims (1)

1. a method of producing aluminum-free steel grade of cold milling non-oriented silicon steel is characterized in that, by smelting composition and rolling, the parameter and annealing of control steel, realizes the production of aluminum-free steel grade of cold milling non-oriented silicon steel; Its concrete control method is:

(1), control comprises the residual aluminium content of bringing in deoxidized aluminium, auxiliary material and the refractory material alloying process, control Als≤0.0010%; The deoxidation of refinement and deoxidation process using silicon;

(2), control the residual element content of smelting nitrogen content and easily forming nitride, the content difference≤0.0020% of control N, Ti, Nb, V;

(3), to take low-temperature heat and finish rolling to carry out temperature-controlled rolling be that the unidirectional district of ferrite is rolling in hot rolling, and control two-phase precipitation state;

A, steel billet of hot rolling when being heated temperature are 1000-1150 ℃, start rolling temperature 〉=950 ℃, finishing temperature 〉=840 ℃, curling temperature 〉=690 ℃;

B, cold rolling employing once or with the secondary cold process of intermediate annealing are rolling to finished product thickness;

C, annealing adopt bell furnace or continuous annealing furnace to carry out wet hydrogen decarburization, recrystallization temperature annealing.