LU81190A1 - IMPROVEMENTS IN DEOXIDATION AND RANGING PROCESSES FOR STEELS - Google Patents

Description

BL-2637 / HM / BM

....... ™ —--— —......- GRAND-DUCHY OF LUXEMBOURG

..... '11 0 ^ yu]'>. <9 ............. Monsieur the Minister of National Economy and the Middle Classes

Title issued: .............. .................. h. "S _. . , _, 4. _

Industrial Property Service

TÂ XrpW LUXEMBOURG

, κρίίΐα ^ ^ ^ y, t * OA Patent Application

To JP. PP

I. Request CERISE DE RESEARCHES METALLURGIQUES - CENTRUM VÖÖR RESEARCH IN DE METALLURG ^ 'ia & stôogterfc' "^ '' '47" rue ..............

Koatoyer, 1040 ....... Brussels »Belgium ..................................... .................................................. .................................................. .....

ι ^ rgse¾tëβ..par ... E., Keyerβ ..., & ... g, gr.eyli¾gegA-Jfcg ^ .cong> ¾n4> gαRr..i¾d. ^ - 46.gttedttί (2> CiRetière, Luxembourg , acting as agents files ....... this twenty ~ six april one thousand nine hundred seventy nine ......................... .... O) at "®2ft ............... hours, at the Ministry of National Economy and Average Classes, in Luxembourg: 1. this request for the obtaining a patent for an invention relating to: "Ferfecticnngseats to deoxidation and staining procedures for .............. (4) steels" ......... .................................................. .................: ................................ .................................................. .................................................. ........................................

declares, assuming responsibility for this declaration, that the inventor (s) is (are):

Paul Emile KÎO.SS "..... 15 rue des Lilag" 4920 Eabourg, Belgium __________________________________________________________ (5> 2. the delegation of power, dated .......... BsUSeilftS ....... ...................... the ...................

3. description in language ............................................ .. of the invention in two copies; 4 .............. T ................ drawing boards, in two copies; 5, the receipt of the fees paid to the Luxembourg Registration Office, loviat-six April ail r.suf cesfc seventy i »» n * .................. .................................................. ......................................

claims for the above patent application the priority of one (s) request (s) of (6) ........................... .................................................. ................. filed in (7) ......................... .................................................. .................................................. ...........

the ................................................. .................................................. .................................................. .................................................. .................................................. ..................... (8) on behalf of ....................... ..............................................-... .................................................. .................................................. .................................................. ....................... (9) * eHf .gcmicile for him (her) and, if appointed, for his representative, in Luxembourg .... ..................................

»4S ma. euXxciSîisres »I.-tu: & - /; - curg saiHciie the issuance of a patent for the invention for the subject described and represented in the aforementioned appendices *, - with postponement of this issuance ....... ....... months.

lIv'î.j ??.?. s __________________ lîL-ift éjvrs ..... ·· —--- ·· -> -........-................. ........... — ........................

· * 9t -) - - · χ ’» ”U · Submission Minutes

The begging patent application has been filed with the Ministry of National Economy and the Middle Classes, Industrial Property Service in Luxembourg, dated: April 26, 1979 δ,. / QV Pr. Minister λ a. " ** f-ér ^. r <V \ e l'Économie Nationale) etjâes Middle Classes,% \ if ^ -... mi 5 / cf 1 .....— -___________ · / · _ ^ - jt . &

EL-2637 / EM / BM

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PATENT D 1 I K V E K T I 0 K

IMPROVEMENTS TO THE DEOXIDATION AND RANGING PROCESSES OF STEELS

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! 'METALLURGICAL RESEARCH CENTER

i CENTRUM VOOR RESEARCH IN DE METALLURGIE

I, non-profit association

Yereniging zoucer vinstoogmerk - * 47 rue Montcyer ί 1040 Bruxelles i .. Belgique î ‘'>') I '\ C 1956/7904.

METALLURGICAL RESEARCH CENTER -CENTRUM VOOR RESEARCH IN DE METALLURGIE,

Non-profit association - Vereniging zondar winstoogmerk in BRUXELLES, (Belgium).

Improvements to deoxidation and steel-making processes.

. The present invention relates to improvements in the processes for deoxidizing and nuancing steels.

In the usual course of the stages of steel making by refining cast iron, phosphorous or not, with the converter, it is well known, once the actual refining in retort is complete, pour the steel into a pocket, in which the usual operations of deoxidization and nuance are carried out.

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Such operations are carried out under difficult conditions, well known to steelmakers and which has always been strived to improve.

Among these difficult conditions or disadvantages, we can cite: awkward access to the pocket, the practical impossibility of precise control, the almost inevitable presence of slag entrained with the steel in the pocket at the time of the emptying of the converter . This last drawback, especially important in the case of phosphorous cast irons, leads to an undesirable rephosphorization of the steel from the slag, once deoxidizing agents have been introduced into the ladle.

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To reduce this last drawback, it has already been imagined to make use of drawer closings of the converter drain orifice, of a float automatically blocking the passage of the slag out of the converter, to quickly raise the converter when the slag is going escape from it as a result of steel.

It seems that these attempts have so far not brought any real improvement to this problem of the separation of slag from ladle steel during the deoxidation and / or shading phases.

The object of the present invention is precisely a process making it possible to obtain the desired quality for steel at this stage of its development, and this in a particularly simple and effective manner.

L The process which is the subject of the present invention is essentially characterized in that, the refining phase of a cast iron, usually carried out with a converter, being completed, the steel present in the converter is poured into a metallurgical ladle, without taking any particular precaution to prevent any slag entrainment. with the steel in the said pocket, materials such as for example lime are added to the metal bath located in the pocket, making it possible to thicken the slag and to make it inactive, and in that you empty the TV.

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said pocket of at least most of its steel, preferably by its bottom and protected from air in a second pocket, the interior of which is advantageously kept away from air, in what is added to the steel in this second pocket, deoxidizing agents and / or tinting agents.

In practice, because the slag in the first pocket has been artificially thickened, it does not actually tend to be entrained with steel in the second pocket, which therefore fills only with steel, the surface superior of it being protected from any oxidation, * thanks to a non-oxidizing atmosphere maintained there, either by direct insuff-1 flation of an appropriate gas (nitrogen - argon, ...), or by ij introduction in the neutral gas bath by porous brick, which also makes it possible to mix the steel and make it more homogeneous.

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The neutral gases and those produced by the deoxy-jation are sucked through a suitable suction line, while the various agents can be brought to the bath, for example by hopper, in large pieces, by powder injection. , with or without non-oxidizing carrier gas.

It is not outside the scope of the invention to maintain the space above the level under appropriate vacuum.

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i steel in the second pocket, at least during the operation of casting the steel therein, which further increases * * the cleanliness of the steel.

The passage of steel out of the first pocket in the second, is advantageously done through a sealed airlock connecting for example the bottom of the first pocket to a cover covering the second.

It should be noted that according to the invention, it is not excluded to add, in the first pocket, a relatively small amount of a deoxidizer such as Al or Mn, provided that · - the product [c] X [oj remains greater than 0.001 and preferably Λ> 4 4.- to 0.002, which can lead to further accentuate the dephosphorization of the steel in the ladle, before thickening of the slag.

The process of the invention has the following advantages in particular: - production of a very homogeneous steel; - high yield of additions, due to the absence of an oxidizing atmosphere; - precision of the analysis; - no unwanted rephosphorization; - Ease of handling, because the first pocket can be easily moved, for example to be placed in a suitable place, on the second pocket; - Ease of keeping the surface of the steel in the second pocket protected from air, even after deoxidation and nuancing; the emptying of the second pocket can be done by its bottom, through a jet-protecting nozzle, as far as the ingot mold.

From a refractory point of view, it is advantageous to provide an internal siliceous coating in the first pocket and basic for the second.

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Claims (8)

5.- 0 "*‘ ί $ i CLAIMS 1. A process for the deoxidation and nuancing of steels, characterized in that the refining phase of a cast iron, usually carried out with a converter, being completed, the steel being in the metallurgical ladle is poured out. converter, without taking any particular precaution to prevent any slag entrainment with the steel in the said pocket, materials such as for example lime are added to the metal bath located in the pocket, allowing thickening | sir the slag and make it inactive, and in that one empties the 'v pocket of at least most of its steel, preferably; by its bottom and sheltered from the air in a second pocket, the interior of which is kept sheltered from the air, so that the steel found in this second is added pocket, deoxidizing agents and / or tinting agents. tj 2. Method according to claim 1, characterized in that a suitable gas (for example nitrogen or argon) is blown above the upper surface of the steel of the second pocket. , so as to protect this surface from oxidation. ! * 3. Process according to either of claims 1 and 2, characterized in that a neutral gas is injected into the steel located in the second pocket, preferably through one or more several porous bricks. ! t! 4. Method according to either of claims 1 to 3, characterized in that the neutral gases or the gases produced by deoxidation being found on the upper surface are sucked through a pipe. steel. i * 1 '^ i 4 C ♦ - w 5. Method according to either of claims 1 to 4 * characterized in that the deoxidizing and / or shading agents are brought to the bath, either in large pieces, for example hopper, or in powder, by example by injection, with or without a non-oxidizing carrier. 6. Method according to either of claims 1 to 5, characterized in that one maintains under appropriate vacuum, 1 space located above the level of the steel in the second pocket at least during the operation pouring steel into this one 7. Method according to either of claims 1 to t characterized in that the passage of steel out of the first pocket in the second is done through a sealed airlock, connected For example the bottom from the first pocket to a rec ** avrant- - ^ a second cover. 8. Method according to either of the claims there "characterized in that a deoxycant in an amount such as aue in the ac is added to the steel in the first pocket. oxygen by the concentration -n carbon remains greater than 0.001 and preferably * than 0.002. / **> t - ---- »... -----.