DE1962964A1 - Manufacture of metal alloys - Google Patents

Description

DIPL..INQ. HELMUT MISSLiNG 63giessen, December 15, 1969

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PATENT LAWYERS 1962964

M / Sn 10.199

Allmänna Svenska Elektriska Aktiebolaget, Västeras / Sweden

Manufacture of metal alloys

The invention relates to a method for producing Metal alloys »e.g. from steel.

In the manufacture of metals or metal alloys must alloy additives of various types and / or deoxidizing agents are generally added to the melt at some point during the manufacturing process can be added. These can be added to the melt in the melting furnace or in a container, e.g. in a ladle or ladle furnace, be added to the melt for completion is poured »The ligation acid or the deoxidizer can be added to the ladle or the ladle furnace before, during or after pouring the melt.

fi (i ..;. Lcu'iin /; 3KUSittKe deoxidizer and are often highly reactive and α been Λ, wherein by luxB UUD / odar by molten slag • ■ j {./«UtiJL'l, rail where the said substances den kairentiaclleii MM; hui! oii IeLeiht being able to get in touch »This becomes the

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Degree of utilization of the additives and deoxidizing agents often low and material costs high.

The invention relates to a method for the supply of alloy additives and / or Itesoxidationsmittel to a Melt, which from öharge au Charge a high and even utilization of the additives or agents and there, through lower costs than previously guaranteed.

The invention is characterized in that an alloying agent and / or a deoxidizer with a boiling point above the melting temperature is introduced in the form of a rod or wire while stirring the melt into a melt located in a furnace or in a pan and making up the main part of the alloy will.

The stirring can be done with an inductive stirrer or by gas purging. The one necessary to lower the bars Force should exceed the buoyancy of the rods so far that the rod-shaped material at least through the largest rope of Bath depth is lowered quickly.

The rods or wires hang vertically and are clamped in a holder at their upper iikide. By vertical lowering of an alloy of unsuitable material through aio slag sum

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Steel bath with simultaneous stirring of the same happens alloying mainly through direct contact between the alloying material and the molten steel. This creates reactions with the oxygen in the air and / or the slags and significantly increases the utilization.

Another benefit of the process is that. that you can freely choose the most suitable time for adding the rod-shaped material. Before that one was often dependent on adding the alloy additives or the deoxidizing agent to the pouring stream when pouring the sciinelse from the melting furnace, for example when pouring it into a ladle, which usually results in a low and uneven utilization of the additives. Now you can choose both the time for introducing the additives and the sequence between several additives while maintaining high levels of utilization and uniformity from batch to batch.

The stirring can be done by gas purging, with electromagnetic Stirrers for multi-phase, low-frequency electricity or by "mechanical stirrers".

With regard to both the alloying additives and the deoxidizing agents, it can be said that the utilization problems hitherto encountered in this connection with regard to reactive, i.e. material with a tendency to oxidation and especially such substances,

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templates,

which have a lower density than the melt / now essentially are resolved.

It is important that you apply the force to the rod-shaped material gives such a value that the buoyancy of the lowered rod (s) is canceled and the rods at least by the largest Part of the bath depth can be lowered. The lowering speed (duration 1 minute) must be relatively high in order to achieve a significant To prevent melting during the immersion process.

The rods must have a certain minimum dimension in order to have sufficient mechanical strength, but they can also be pretty thick. As an example, it can be mentioned that it has been shown that a cross section for aluminum of 75 x 75 mm is well suited.

The invention is explained in more detail below with reference to the drawing.

A steel melt is located in a pan 10 with a lid 11. This should, apart from those already added in the melting furnace Alloy additives, including aluminum, can be added. The pan is provided with an arrangement 12 for electromagnetic stirring, but gas purging through the bottom of the pan is also possible.

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On a fastening arrangement 13 of sufficient weight, For example, on a steel body suspended from a trolley or a slewing crane, rods are conveniently used made of an alloy additive, here aluminum, attached. The rods can be attached to the mounting arrangement with the aid of Holders 14 with wedges 15 are attached to this. The rods become quite fast when the melt is stirred (in the course of one minute) lowered into the molten steel under the effect of the total weight of the holder 13 and rods 16, the weight being determined in such a way that the buoyancy comes from the weight ™ is overcome. The last one can also be achieved by a mechanical force acting on the rods directly or via a Lever arm is exercised. It can be pushed in up to a marking 17, i.e. up to the position shown in the figure, which is chosen so that the melted material gives the steel the right composition. After lowering it will the rod material is alloyed in by direct contact with the molten steel under stirring and one obtains a high utilization. Materials other than aluminum can also be | be alloyed in the same way as e.g. ferro alloys, Titanium, deoxidizers with Si, Ga and Al and alloys thereof.

The utilization of aluminum in the tests carried out was between 63 and 83 #, depending on the test method. This

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can be compared with an aluminum utilization of 29 f * ₉ that is obtained when aluminum is added to the ladle before the melt is poured in. The following table shows the results "in various tests in connection with the production of silicon-alloyed steel for electrical steel:

Melted
stole
kg 240 Consumed
Al crowd
kg Final salary
Al
Weight $> Al utilization
* 19th 560 47.0 0.16 63 18th 730 86.8 0.31 67 18th 370 37.0 0.14 71 17th 720 61.2 0.25 71 19th 070 38.0 0.14 73 18th 700 64.2 0.16 73 18th 300 59.7 0.25 78 19th 37.5 0.16 83

The differences in utilization can be explained by the fact that the stirring was continued for different times after the addition was completed. In order to achieve optimum utilization, it is important that the stirring is stopped in cases _where the melt comes into contact with the oxygen in the air during stirring, as soon as a satisfactory homogenization, e.g. of the alloy addition in the melt, has been achieved an approx. 20 t bulk at the latest

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- 7 after. 2 minutes after the addition is complete.

The end product of the above-mentioned experiment is, as stated, steel for electrical steel which, in addition to iron, has a carbon content of $ 0.30, a silicon content of between $ 1.0 - $ 3.5 and an aluminum content of between $ 0.15 and $ 0.35 .

As already mentioned, the method can be used in the manufacture of a large number of metal alloys. It is particularly valuable if the melt contains expensive, reactive alloy additives such as aluminum or titanium, as well as deoxidizing agents with high kilo prices to be added.

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Claims (6)

Patent claims: 1. Process for the production of metal alloys, e.g. Steel, characterized in that the main part of the alloy is in a furnace or in a ladle making up melt an alloy additive and / or a deoxidizer with a boiling point above the melting temperature in rod or wire form with simultaneous stirring the melt is introduced. 2. The method according to claim 1, characterized in that a lowering of the rod-shaped or wire-shaped additive causing Force outweighs the buoyancy of the additive in the melt so that the additive is quickly lowered to the bottom of the melt can be. 3. The method according to claim 1, characterized in that one or more aluminum rods are lowered into a steel melt which contains iron and carbon and silicon, whereby an end product with a silicon content of 1.0-3.5 percent by weight is obtained and one Aluminum content of 0.15-0.90 fo, preferably 0.20-0.35 ? °, with an Al utilization of 70-80 ia. 4. The method according to claim 3, characterized in that in the melt, before or after the aluminum feed, a deoxy 009827/1338 - 9 - dationsmittel and possibly at the same time a Legienmgszusats such as silicon iron, silicon calcium and / or calcium aluminum is introduced. 5 »Method according to one or more of the preceding claims, characterized in that the introduction of alloy additive and deoxidizer into the melt at the same time or happen one after the other in any order. 6. The method according to one or more of the preceding claims, characterized in that rods in the melt with a minimum diameter of 20 mm, preferably at least 50 mm, e.g. 50 χ 50 mm or 50 mm in diameter. 00 9827/1338 BATH ORIGINAL Blank page