CN102002619B

CN102002619B - Rare-earth silicon alloy for silicon steel production and preparation method thereof

Info

Publication number: CN102002619B
Application number: CN201010535982.6A
Authority: CN
Inventors: 梅泽锋; 宋钧健; 夏宏梁; 章汉云
Original assignee: JIANGNAN IRON ALLOY CO Ltd JIANGSU
Current assignee: JIANGNAN IRON ALLOY CO Ltd JIANGSU
Priority date: 2010-11-09
Filing date: 2010-11-09
Publication date: 2014-01-15
Anticipated expiration: 2030-11-09
Also published as: CN102002619A

Abstract

The invention relates to rare-earth silicon alloy for silicon steel production and a preparation method thereof. The rare-earth silicon alloy comprises the following components in percentage by weight: 45-60 percent of Re, 40-55 percent of Si, not more than 0.5 percent of C, not more than 0.002 percent of P and not more than 0.002 percent of S. The preparation method comprises the following steps of: (a) material selection: selecting high-quality metal silicon with the Si content of larger than or equal to 99 percent and mixed rare-earth alloy with the TREM content of larger than or equal to 98.0 percent as raw materials; (b) smelting: selecting an intermediate-frequency and a power-frequency induction electric furnaces lined with a magnesite or graphite crucible as a smelting tool; adding mixed rare-earth metal into the furnaces, blowing argon for liquid protection, forming a protecting layer by adopting molten salt and adding metal silicon; and (c) after the furnace material is completely melted, fully stirring and casting an alloy block. The invention ensures that the loss of real-earth metal in production is greatly reduced, ensures the component of a smelted product, improves the toughness and fatigue resistance of silicon steel and can obtain a silicon steel material with a high magnetic induction characteristic.

Description

A kind of preparation method of the rare-earth silicon alloy of producing for silicon steel

Technical field

The invention belongs to field of metallurgy, be specifically related to a kind of rare-earth silicon alloy and preparation method who produces for silicon steel.

Background technology

Silicon steel is that silicon content is in 3% left and right, its main component is the ferro-silicon of iron, being the indispensable important non-retentive alloy of electric power, electronics and war industry, is also the Metallic Functional Materials of output maximum, is mainly used in making the iron core of various motors, generator and transformer.Silicon steel is divided into hot rolled silicon steel sheet, cold-rolled orientation silicon steel sheet, cold rolling non-orientation silicon steel sheet.Hot rolled silicon steel sheet is because its utilization ratio is low, and country has force and required to eliminate.Cold rolling non-orientation silicon steel sheet in process of production, stricter to the control of carbon, nitrogen, oxygen, sulphur, particularly to sulphur, controls stricter; Silicon steel all requires removal impurity to obtain high magnetic strength, performance that iron loss is low in process of production simultaneously.Patent No. 2006/0030597.X adopts sweetening agent to carry out Vacuum Desulfurization.When producing cold-rolled orientation silicon steel sheet, adopt decarburizing annealing and coating to take the annealing separating agent that Mgo is main component, in high-temperature annealing process, steel plate generation secondary recrystallization, Mg2SiO4 bottom form and purify remove steel grade S, N etc. to magnetic harmful element.But aforesaid method impurity elimination complex process, consumption energy consumption power, and impurity elimination difficulty, spread in existing impurity elimination technology, all has problems.

At present, the additive that rare earth adopts as steel-making is widely used, three effects greatly that mainly contain of rare earth in steel: cleaning action, metamorphism and Microalloying Effect, be that rare earth adds and in molten steel, can play desulfating and deoxidation and change inclusion morphology, and can improve the physicalies such as plasticity-, toughness etc. of steel.Now in STEELMAKING PRODUCTION, the most frequently used two kinds of methods that have are: the one, and rare earth alloy, block rare earth ferrosilicon alloy, drops into for large bag in the past, and large bag pressure enters, and powdery is generally used in large bag the method such as dust, die casting feed trumpet dusts and adds in steel; The 2nd, norium, makes silk or rod, and silk, for ladle, feed trumpet or continuous cast mold, is used in wire feeder feeding steel, and rod adopts the method for hanging in mould to fuse in steel.Although can there is very strong desulfurization, deoxidizing capacity by rare earth metal, if but when rare earth metal is directly dropped in steel-making, because the rare earth-oxygen-sulphur producing is mingled with etc., fusing point is high, than great, being difficult to assemble floating gets rid of, thereby in the process of removal of impurities, can, because getting rid of the purity that has reduced not to the utmost molten steel, affect quality product simultaneously.

Summary of the invention

For overcoming above-mentioned defect, the object of this invention is to provide a kind of rare-earth silicon alloy of producing for silicon steel and preparation method thereof, thoroughly solve impurity element in silicon steel production and remove difficult technical problem, improved toughness and the fatigue resistance of silicon steel, can obtain the silicon steel material of high magnetic strength characteristic simultaneously.

For achieving the above object, technical scheme of the present invention is: a kind of rare-earth silicon alloy of producing for silicon steel, and its composition weight percent is: rare earth Re:45-60%; Silicon Si:40-55%; Carbon C≤0.5%; Phosphorus P≤0.002%; Sulphur S≤0.002%.

Preparation method for the production of above-mentioned rare-earth silicon alloy is as follows, carries out according to the following steps:

(a) select the high-test metal silicon of Si >=99%; Selecting norium TREM >=98.0% is raw material, calculates the weight of raw material in the ratio of the rare-earth silicon alloy middle-weight rare earths Re of required production and silicon Si;

(b) melting: select the intermediate frequency, line frequency furnace that are lined with magnesia or plumbago crucible as melting instrument; In stove, add norium, be blown into the protection of argon gas liquid level simultaneously, then adopt melting salt to form protective layer, finally add Pure Silicon Metal;

(c) after described furnace charge all melts, fully stir, cast alloy block.

As a further improvement on the present invention: in the present invention, norium selects to press the calculation of composition weight percent meter, comprising: lanthanum La:28-32%; Cerium Ce:54-58%; Praseodymium Pr:2-4%; Neodymium Nd:9-11%.During this is abundant, not only contain abundant cerium, and contain abundant lanthanum, in removal of impurities, utilized lanthanum than cerium, to there is the characteristic of stronger deoxidizing capacity, further can reduce the oxygen level in molten steel, and be conducive to the upper row of impurity; And price is relatively cheap.

As the preferred embodiments of the present invention: described melting salt is the mixture of NaCl and KCl.

In order better to reach provide protection, reduce the loss of rare earth alloy, in step (b), to be blown into the pressure of argon gas be 0.15-0.20Mpa in control.

The additive of this product for replacing former rare earth metal to adopt as steel-making, not only better utilised three effects greatly of rare earth in steel, but also can regulate the silicone content in silicon steel, kill two birds with one stone, simplified technique, improved efficiency; And the rare-earth silicon alloy that the present invention produces is worked as for smelting silicon steel, in refining process, not only can play the chemical reaction of harmful elements such as accelerating O, S, N, P in rare earth and steel, and the floating that is more conducive to steel inclusion gets rid of, realize steel water purification, improve quality; Residual rare earth (REM) in non-oriented silicon steel sheet, adopts the light cold-rolling practice of pressing of secondary, can make crystal grain diameter be grown up fully, can obtain the siliconized plate of high magnetic strength characteristic.Due in this product of melting rare-earth silicon alloy, can further reduce the impurity such as raw material itself middle O, S, N, P, reduced removal of impurities difficulty, improved dust removal rate.

The removal principle of rare earth in steel-making is:

2（Re）+ 3（O） = Re2O3

2（Re）+ 3（S） = Re2O3

（Re）+（P） = ReP

（Re）+（N） = ReN

The method relating in the present invention has adopted two kinds of different protected modes, and rare earth metal loss is aborning reduced greatly, has guaranteed the composition of product after melting, for follow-up silicon steel, produces the assurance in matter, amount is provided.

Embodiment

Below by embodiment, the present invention is further illustrated.

Embodiment 1: the preparation method of the rare-earth silicon alloy of producing for silicon steel the present invention relates to, carries out according to the following steps:

Selecting silicon content to be greater than 99% Pure Silicon Metal and norium REM >=98.0% is raw material; Wherein in norium, the per-cent of Re is: press composition weighing scale and calculate, La:29.8%, Ce:55.5%, Pr:3.2%, Nd:10.1%.

By above-mentioned two kinds of composition (Re50%; Si48%) batching; in the middle of adopting, there is the intermediate frequency furnace of plumbago crucible outer lining magnesia to melt; first in stove, add mixed rare earth metal; and be blown into the argon gas that pressure is 0.16MPa, and produce after liquid, adding NaCl:KCl is the melting salt protection of 1:1; add again whole Pure Silicon Metals, after fusing, cast rare-earth silicon alloy piece.

After testing, the composition of rare-earth silicon alloy piece (% by weight) is as follows: rare earth Re 49.2%; Silicon Si 47.41%; Carbon C≤0.18%; Phosphorus P≤0.001%; Sulphur S≤0.001%.

Embodiment 2, the present invention relates to a kind of rare-earth silicon alloy of producing for silicon steel, and its composition weight percent is: rare earth Re 55%; Silicon Si 43.8%; Carbon C≤0.18%; Phosphorus P≤0.001%; Sulphur S≤0.001%.

The preparation method who the present invention relates to a kind of rare-earth silicon alloy of producing for silicon steel, carries out according to the following steps:

Selecting silicon content to be greater than 99% Pure Silicon Metal and norium REM >=98.0% is raw material; Wherein in norium, the per-cent of Re is: press composition weighing scale and calculate, La:31%, Ce:54.5%, Pr:3.5%, Nd:9.5%.

By above-mentioned two kinds of compositions (Re55%, Si43.8%) batching, select the line frequency furnace that is lined with magnesia as melting instrument; In stove, add whole noriums, be blown into the argon gas liquid level protection of 0.15Mpa simultaneously, then adopt melting salt to form protective layer, finally add Pure Silicon Metal.After described furnace charge all melts, fully stir, cast alloy block.

The present invention thoroughly solves impurity element in silicon steel production and removes difficulty, inclusion is difficult to assemble the technical problem that floating drains, improved purity, toughness and the fatigue resistance of silicon steel, simultaneously residual rare earth can obtain the silicon steel material of high magnetic strength characteristic by the light cold-rolling practice of pressing of secondary.

Claims

1. a preparation method for the rare-earth silicon alloy of producing for silicon steel, the composition weight percent of wherein said rare-earth silicon alloy is: rare earth RE:45-60%; Silicon Si:40-55%; Carbon C≤0.5%; Phosphorus P≤0.002%; Sulphur S≤0.002%, is characterized in that: carry out according to the following steps:

(a) selection: the high-test metal silicon of selecting Si >=99%; Select norium TREM >=98. 0% for raw material; Wherein, described norium composition comprises: La:28-32%; Ce:54-58%; Pr:2-4%; Nd:9-11%, its composition counts by weight percentage;

(b) melting: select the intermediate frequency, line frequency furnace that are lined with magnesia or plumbago crucible as melting instrument; In stove, add norium, be blown into argon gas liquid level protection simultaneously, after adopt again melting salt to form protective layer, finally add Pure Silicon Metal; Described melting salt is the mixture of NaCl and KCl;

(c) after furnace charge all melts, fully stir, cast alloy block.

2. the preparation method of the rare-earth silicon alloy of producing for silicon steel according to claim 1, is characterized in that: the pressure that is blown into argon gas is 0. 15-0. 20MPa.