SE124005C1

SE124005C1 -

Info

Publication number: SE124005C1
Authority: SE
Publication date: 1948-01-01

Description

Uppfinnare: K. Oganowski. Inventor: K. Oganowski.

Uppfinningen avser problem som mota vid belaggning av metallremsor, folier eller liknande foremal med smalt aluminium eller liknande metaller vid den tillverkningsmetod dar de artiklar, som skola belaggas, passera genom en huv med skyddande atmosfar ned i metallbelaggningsbadet. The invention relates to problems encountered in coating metal strips, foils or similar articles with narrow aluminum or similar metals in the manufacturing method in which the articles to be coated pass through a hood with a protective atmosphere down into the metal coating bath.

Ett exempel pa en sadan metod beskrives i amerikanska patentet nr 2 110 893, dar metallremsan forst drages genom en oxidationsugn sâ att oljor och andra kolhaltiga bestandsdelar brannas bort fran dess ytor och dar en jamn och mikroskopiskt tunn oxidfilm bildas, varefter remsan drages genom en ugn med reducerande atmosfar, Or, bland annat, den tunna oxidfilmen reduceras och lanmar remsans ytor fullstandigt rena och mycket mottagliga for den smalta belaggningsmetallen. Remsan ledes genona en hu-cfritn reduktionsugnen ned i badet medan den annu skyddas av en neutral eller reducerande atmosfar och utan att behandlas med flussmedel. An example of such a method is described in U.S. Patent No. 2,110,893, where the metal strip is first drawn through an oxidation furnace so that oils and other carbonaceous constituents are burned away from its surfaces and where a smooth and microscopically thin oxide film is formed, after which the strip is drawn through an oven. with reducing atmosphere, Or, among other things, the thin oxide film is reduced and leaves the surface of the strip completely clean and very susceptible to the narrow coating metal. The strip is passed through a hu-cfritn reduction furnace into the bath while still being protected by a neutral or reducing atmosphere and without being treated with flux.

Vid belaggning av jarnfolier med aluminium medelst neddoppning i hett bad har, trots den tillforda skyddande atmosfaren, svarigheter ofta mot pa grund av bildning eller avsattning av material pa folieremsan, som pa ett fordarvligt satt paverkar den smalta belaggningsmetallens vidhaftning. Den kvarvarande belaggningen har ytor, som ej belagts, varierande fran store. lappar pa 50 c,7, eller mera av den totala ytan ned till obetydliga blasor. I dessa är belaggningen, fastan narvarande, ej fast bunden vid basmetallen och flagar latt av dã metallen vrides, bojes eller bockas. Knappnalsstora hal i belaggningen upptrada aven ibland. When coating iron foils with aluminum by immersion in a hot bath, despite the added protective atmosphere, they often have similarities due to the formation or deposition of material on the foil strip, which in a detrimental way affects the adhesion of the narrow coating metal. The remaining coating has surfaces that have not been coated, varying in size. patches of 50 c, 7, or more of the total surface down to insignificant blisters. In these, the coating, although present, is not firmly bonded to the base metal and flakes are easily twisted, bent or bent by the metal. Button-sized halls in the pavement also sometimes appeared.

Uppfinningens viktigaste andarnal ãr att Overvinna de svarigheter som skisserats. Delta och andra andamal beskrives nedan, forfaringssattet och delarnas konstruktion och sammansattning utgor blott ett exempel pa. en utforingsform. Hanvisning gores till bifo gade ritning som visar en tvarsektion genom en gryta rued smalt metal!, en del av huven och diverse andra anordningar som askadligOra en av uppfinningens former. The most important spirit of the invention is to overcome the responsibilities outlined. Delta and other objects are described below, the procedure and the construction and composition of the parts are only an example. an embodiment. Manual reference is made to the accompanying drawing which shows a cross section through a pot of rued narrow metal!

Man har forut forstatt att den skyddande atmosfaren i huven, som maste vara reducerande, under vissa omstandigheter tenderar aft hliva svagt oxiderande genom temperaturens inverkan, genomsom kan lacka in i hu- yen eller genom bestandsdelar som avgivas av remsan spiv, och man har f5rsiikt behandla atmosfaren i huven med ett reningsmedel, exempelvis inetallangor som reagera begarligare med syre an ytan pa remsan. It has previously been understood that the protective atmosphere in the hood, which must be reducing, under certain circumstances tends to be slightly oxidizing due to the action of temperature, which can lacquer into the housing or through components emitted by the strip spiv, and care has been taken to treat the atmosphere in the hood with a cleaning agent, for example metal vapors which react more favorably with oxygen to the surface of the strip.

Under det att en renande atmosfar hindrar remsans oxidation har hittills anvanda re-flings- och andra atmosfarreglerande metoder ej lost del problem for vilket donna uppfinning är avsedd. Det har nu upptackts att svarigheterna att framstalla en tillrackligt ren yta pa remsan orsakas av amnesbildningar som till storsta delen men ej fullstandigt harleda sig fran en reaktion i badet sjalvt eller ocksa fran forangad metall fran badet som reagerar med bestandsdelar i atmosfaren. Dessa dmnen hafta fast vid remsan och hindra god f5rbindning med belaggningsmetallen. En del av dessa amnen kan uppkomma i atmosfaren Over badet och finna vagen till rem-sans fria ytor innan remsan doppas ned i badet. Men storsta delen synes bilda ett slagglager flytande pa badets yta, som da det kommer i kontakt med remsan, haftar vid dess ytor och drages ned i badet med remsan, vilket har ovan angivna olagenheter till Rd. While a purifying atmosphere prevents the oxidation of the strip, heretofore used reflecting and other atmospheric control methods have not solved some of the problems for which this invention is intended. It has now been discovered that the difficulties of producing a sufficiently clean surface on the strip are caused by amnesic formations which for the most part but not completely result from a reaction in the bath itself or also from vaporized metal from the bath which reacts with constituents in the atmosphere. These blanks adhere to the strip and prevent good connection with the coating metal. Some of these substances may arise in the atmosphere over the bath and find their way to the free surfaces of the strip before the strip is dipped into the bath. But most of it seems to form a slag layer floating on the surface of the bath, which when it comes in contact with the strip, adheres to its surfaces and is pulled down into the bath with the strip, which has the above-mentioned ills to Rd.

Bland dessa amnen finnas nitrider bildade genom reaktion mellan badet och kvave, som bildar en del av den skyddande atmosfaren eller ocksa kommer in i denna pd. grund av oaktsamhet. Vissa skyddande atmosfarer ha hog kvavehalt sasom i de fall da en reducerande gas innehallande frill vate, som bildas vid ammoniaks sonderdelning, anvandes. Oxider, hydroxider bildade vid re- 2— — aktion med vattenanga, och andra amnen aro aven narvarande. Among these substances are nitrides formed by reaction between the bath and nitrogen, which form part of the protective atmosphere or also enter this pd. due to negligence. Some protective atmospheres have a high nitrogen content, such as in cases where a reducing gas containing frill water, which is formed during ammonia probe division, is used. Oxides, hydroxides formed on reaction with water vapor, and other substances are also present.

Uppfinningen baseras pa upptackten att det är mOjligt att utforma en belaggning pa hadets yta som är av pulverlik natur men ej haftar vid rernsan. Denna belaggning verkar aft i atminstone storsta mOjliga utstrackning hindra reaktion "Italian badet och bestandsdelarna i atmosfaren, on i varje fall neutralisera inverkan av och medverka till att saclarta nitrider, oxider och liknande amnen, som kunna bildas pa annat stilt, ej Nina vid remsan. The invention is based on the discovery that it is possible to design a coating on the surface of the hat which is of a powdery nature but does not adhere to the pipe. This coating seems to prevent, at the greatest possible extent, the reaction of the Italian bath and the constituents of the atmosphere, in any case neutralizing the effect of and contributing to sacral nitrides, oxides and similar substances which may be formed elsewhere, not Nina at the strip.

Man har exempelvis funnit, att det ar mojligt aft pa ett aluminiumbads yta Astra ett lager, som huvudsakligen bestar av pulvriserat natriumaluminat yilket ej haftar vid den passerande remsan och vilket hincirar alurniniumet att sjalvt bilda ett skadligt lager. It has been found, for example, that on the surface of an aluminum bath Astra it is possible to have a layer which mainly consists of powdered sodium aluminate which does not adhere to the passing strip and which prevents the aluminum itself from forming a harmful layer.

Det är inte praktiskt att fOrsoka alstra ett sadant lager genom att tillsatta metalliskt natrium till badet i haven. En del smalt natrium kommer aft flyta pa badets yta och da det kommer i kontakt med remsan uppstar en tunn belaggning under aluminiurnet. Dit den heta belagda remsan trader ur badet ut i luften ager en snabb oxidation ram med det resultatet att hada belaggningarna forstoras. Forsok att desoxidera badet med natrium ha darfor visat sig vara ineffektivt. It is not practical to attempt to produce such a layer by adding metallic sodium to the bath in the oceans. Some narrow sodium will again float on the surface of the bath and when it comes in contact with the strip, a thin coating will form under the aluminum urn. Where the hot coated strip exits the bath into the air, a rapid oxidation framework acts, with the result that the coatings are enlarged. Attempts to deoxidize the bath with sodium have therefore been shown to be ineffective.

A andra sidan itr jute en enkel tillsats av angor Iran metalliskt natrium till atmosfaren i haven effektiv for nagot annat andamal an desoxidering eller rening ay atmosfaren och avhjalper icke de svarigheter, som denna uppfinning avser att bemastra. Ingen effektiv natriumaluminatbelaggning bildas pa badet under dessa omstandigheter. On the other hand, a simple addition of Iranian metallic sodium to the atmosphere of the oceans is effective for any other purpose than deoxidation or purification of the atmosphere and does not overcome the responsibilities which this invention seeks to overcome. No effective sodium aluminate coating is formed in the bath under these conditions.

Emellertid kan uppfinningens mid appnas, om man alstrar eller infor natriumangor i narheten av aluminiumets yta inne haven, titan att bringa vatskeformig eller fast natrimn kontakt med den smalta belaggningsmetallen. Under dessa omstandigheter kan det onskade lagret bildas pa aluminiumbadets yta, och kontinuerligt fornyas om sit Or behdvligt, utan skapande eller kondensation av nagot flytande vatskeformigt natriumlager pit badet. However, if one creates or introduces sodium vapors near the surface of the aluminum inside the oceans, titanium can bring liquid or solid sodium contact with the molten coating metal. Under these conditions, the desired layer can be formed on the surface of the aluminum bath, and continuously renewed if necessary, without creating or condensing any liquid liquid sodium layer in the bath.

Det Or nodvandigt att natriumangorna alstras eller inf5ras i haven mellan badets yta och det stalle dar den skyddande atmosfaren kommen in tvilket vanligen Or placerat 1 havens nedre del alldeles intill en klocka, utgarande havens nedersta parti), eftersom annars natriumangorna i hog grad kanna spadas at av den skyddande atmosfiiren eller ocksit ryckas riled av denna bort fran badets yta. Om natiumangorna genereras pa nagot annat static och inforas i haven eller klockan maste atgarder vidtagas for att forhindra angornas blandning med atmosfaren i haven och fiir att fOrhindra icke anskvard tarbulens inne i haven. It is necessary for the sodium vapors to be generated or introduced into the oceans between the surface of the bath and the place where the protective atmosphere enters, which is usually placed in the lower part of the oceans right next to a bell, the lower part of the oceans, because otherwise the sodium vapors can be of the protective atmosphere or oxit is riled by it away from the surface of the bath. If the sodium vapors are generated on some other static and introduced into the oceans or the clock, action must be taken to prevent the vapors from mixing with the atmosphere in the oceans and to prevent unintentional turbulence inside the oceans.

Det har konstaterats att uppfinningens an damal pa ett mycket lampligt satt emits om i haven eller klockan en behallare Oppen uppat och omgivande remsan eller orn skilda behitllare pit ornse sidor om remsan anordnas. I dessa behallare inlagges da och da metalliskt natrium vilket smatter och sakta forangas pa grand av att badets varme ledes till detsamma genom behallarna. En fordel med en enda behallare Or att endast en anordning fOr tillforsel av natrium Or nodvandig, den smalta metallen rinner at over och tacker alla delar av behallarens botten. DA foliematerial behandlas Or det lampligt att anordna en forangningsbehallare p a foliens hada sidor eftersom annars natriumangorna garna bli mer eller mindre instangda pa remsans ena sida. Den oppna Ovre kanten pa behallaren eller behallarna fir belagen mycket nara den yta pit badet, som hlottas inne i haven eller klockan och natriumangbildningen vid detta still-le tjanar det andamal, som ovan beskrivits. Den oppna (tyre kanten pa behallaren skall placeras under den skyddande atmosfarens inloppsoppning i haven. It has been found that the dam of the invention is emitted in a very suitable manner if in the seas or at a container Open upwards and the surrounding strip or separate containers pit or sides of the strip are arranged. Metallic sodium is occasionally added to these containers, which is slowly and slowly evaporated due to the fact that the heat of the bath is conducted to the same through the containers. An advantage of a single container is that only one device for supplying sodium is necessary, the narrow metal flows over and tackles all parts of the bottom of the container. When foil material is treated, it is advisable to arrange an evaporation container on the hot sides of the foil, otherwise the sodium vapors will become more or less trapped on one side of the strip. The open upper edge of the container or containers is coated very close to the surface of the bath, which is heated inside the oceans or the bell, and the sodium vapor formation at this still serves the purpose described above. The open (thin edge of the container) should be placed under the inlet opening of the protective atmosphere in the oceans.

Enligt figuren Or 1 en gryta for smith belaggningsmetall, exempelvis innehallande smalt aluminium 2. Remsan 9, som kommer trim en reduktionsugn, passerar forst genom en hay 4 1 vilken den skyddas av en reducerande atmosfar, till exempel sonderdelad ammoniak, gar ned i badet oeh passerar runt en vats 3 sit att den gar -Lipp ur badet utanfor haven 4. Haven avgransas nedat av en klocka vans kanter straeka sig under det smatta aluminiumets yta. Ett inlopp for den skyddande atmosfaren Or betecknat med 6 nara havens nedre ande. According to Figure 1, a pot for smith coating metal, for example containing narrow aluminum 2. The strip 9, which will trim a reduction furnace, first passes through a shark 4 1 which it is protected by a reducing atmosphere, for example probed ammonia, goes down into the bath oeh passes around a reed 3 sit that it goes -Lip out of the bath outside the oceans 4. The oceans are delimited downwards by the edges of a bell vans stretching below the surface of the matted aluminum. An inlet for the protective atmosphere Or denoted by the lower spirit of the 6 seas.

Kloekan Or i delta fall sit anordnad, nit fOrutnaninda behallare omsluter remsan och behidlaren Or tillverkad pit sit salt att klockans vaggar aro bajda inat vid 7 °eh 8 on sedan uppatbojda inne i kloekan sasom en krage 10. Dessa delar Ore svetsade eller pa annat salt hopfogade sit att klockans vaggar och delarna 7, 8 och 10 bilda en uppat tippen behallore omslutande remsan. Det smalta aluminiumet stiger app i kragen 10 och dess yta ligger hilt intill kragens ovre kant. Kloekan Or in delta case sit arranged, nit fOrutnaninda container encloses the strip and the container Or manufactured pit sit salt that the clock's cradles are bent inwards at 7 ° eh 8 on then bent up inside the kloekan like a collar 10. These parts Ore welded or on other salt joined together to form the cradles of the watch and the parts 7, 8 and 10 to form an upturned behallore enclosing strip. The narrow aluminum rises app in the collar 10 and its surface lies completely next to the upper edge of the collar.

Metalliskt natrium infOres i den oppna behallaren dar det smatter och rinner omkring tackande botten pa behallaren. Det forimgas sit smaningom och angorna bildas toll intill det smalta aluminiumets yta och de tunga natriumangorna stromma i den beskrivna apparaten ned inot aluminiumbadets yta. Det metalliska natriumet i behallaren Or betecknat 11. Metallic sodium is introduced into the open container where it slams and flows around the thanking bottom of the container. It is formed gradually and the vapors form tolls next to the surface of the narrow aluminum and the heavy sodium vapors flow in the described apparatus down into the surface of the aluminum bath. The metallic sodium in the container Or denoted 11.

For natriumets inforande i behallaren, vilket Or nodvandigt dO. och dit, anordnas lampligen en rorledning 12 utrustad med ett par ventiler eller slussar 13 och 14. Anvandandet av tvit snabboppnande ventiler i serie gor det mojligt att infora natriumet utan att luft kommer in i klockan. Natriumet infores lamp- — —3 ligen i fast form i bitar eller kulor av lamp-hg storlek fastan det om sh onskas fore inforandet Oven kan smaitas. Natriumets smallning i apparaten gOr det onodigt att fore inforandet smalta detsamma och besvarligheten att handskas med flytande natrium i ror och rOrledningar dar det kan stelna och orsakar tilltappning undvikes darigenom. Naturligtvis Or det underforstatt att huven 4 °eh klockan 5 star i fOrbindelse med varandra men Oro avstangda fran oppna luften och att badet bildar klockans undre slutna vagg. For the introduction of sodium into the container, which Or necessary dO. and there, a pipeline 12 is suitably provided with a pair of valves or locks 13 and 14. The use of two quick-opening valves in series makes it possible to introduce the sodium without air entering the bell. The sodium is introduced into the lamp- - —3 in solid form in pieces or bulbs of lamp-hg size, although it is desired for the introduction. The oven can be forged. The narrowing of the sodium in the apparatus makes it unnecessary for the introduction to melt the same and the difficulty of handling liquid sodium in pipes and pipes where it can solidify and cause draining is thereby avoided. Of course, it is understood that the hood 4 ° eh at 5 o'clock is in communication with each other but Oro is spaced from the open air and that the bath forms the lower closed cradle of the bell.

Denna uppfinning Or ej begransad till belaggning av flagon speciell metallprodukt, men Or sarskilt lampad for trad, folier och Oven enskilda artiklar och da folier eller enskilda foremal behandlas aro lampliga hjalpmedel anordnade sO all arbetsstyckena forflyttas genom huven och kloekan ned i badet och upp igen ur detsamma. This invention is not limited to the coating of flake special metal product, but is particularly lamped for wire, foils and even individual articles and when foils or individual objects are treated there are suitable aids arranged so that all the workpieces are moved through the hood and claw down into the bath and up again. the same.

Uppfinningen har beskrivits i forbindelse med anvandningen av natrium, men alla alkalimetaller ha befunnits vara dugliga om de anyandas ph lampligt salt for att bilda en skyddande finga Over badet och en pulverformig belh.ggning ph dess yta, som ej uppvisar nagon vidhaftningsfOrmaga mot folierna, remsorna eller de enskilda foremalen och som har fOrmagan att forhindra bildning av skadliga vidhaftande arnnen, vilka forstora den smalta metallens bindning vid basmetallen. Till exempel tjana kalium och litium delta andamal mycket bra. The invention has been described in connection with the use of sodium, but all alkali metals have been found to be capable of any other suitable salt to form a protective finger over the bath and a powder coating on its surface which does not exhibit any adhesion to the foils, strips. or the individual molds and which have the ability to prevent the formation of harmful adhering hearths, which increase the bond of the molten metal to the base metal. For example, potassium and lithium delta andamal serve very well.

Forfaringssattet anvandes foretradesvis fOr belaggning av jam eller mjukt stal med en smalt belaggningsmetall men inskranker sig icke till dessa basmetaller offer som de vidhaftande kemiska foreningar, som inverka ph aluminiums sammanbindning med jam och stal Oven phverka andra metaller. Dessutom bor underf5rstas, att medan uppfinningen beskrivits i saraband med aluminium som belaggningsmetall, den Oven Or anvandbar for aluminiumlegeringar med andra metaller och Oven for smalta belaggningsmetaller, vilka ej innehalla aluminium men ha formaga att mengera med kvave, syre, vattenanga och varvid vidhaftande ytslagg bildas ph badet och ingriper storande vid belaggningen. The process is preferably used for coating jam or mild steel with a narrow coating metal but is not limited to these base metal victims such as the adhering chemical compounds which affect the bonding of aluminum with jam and steel to other metals. In addition, it should be understood that while the invention has been described in conjunction with aluminum as the coating metal, it is also useful for aluminum alloys with other metals and ovens for narrow coating metals which do not contain aluminum but are capable of mixing with nitrogen, oxygen, water vapor and adhering surface slag. ph bath and interferes with the coating.

Claims

Patent claim:

1. A method of coating metal formals with small coating metal, characterized in that the metal frontal passes through a hood into a hat with the narrow coating metal, that steps are taken to maintain a protective atmosphere in the hood, soul mainly or non-oxidizing to the base metal and supply an atmosphere containing a flask of alkali metal vapor between the surface of the narrow coating metal bath and the protective atmosphere.

2. A method according to claim 1, characterized in that a quantity of alkali metal is enclosed within the hood in such a way that heat exchange can take place with the bath whereby the alkali metal is melted and slowly evaporated and that the molten alkali metal does not come into contact with the narrow bath coating metal.

3. A method according to claim 1 or 2, characterized in that the surface of the bath maintains a reducing gas atmosphere containing nitrogen and that an atmosphere consisting of alkali metal vapor is arranged between said atmosphere and the surface of the bath.

Procedure according to any one of the preceding claims, characterized by measures to prevent such slag formations on the surface of the bath which adhere to the base metal and the large connection between it and the metal in the bath, that the slag formation is prevented thereby on those of the bath surfaces by which the metal coating powder, a powdery layer consisting of an alkali aluminate is immersed, which does not form the base metal and the formation of this layer takes place by means of a gas-rich alkali metal tube arranged immediately over the surface of the bath.

5. Apparatus for carrying out the process set according to any one of the preceding claims, characterized by a pot for a molten bath of a coating metal, a hood through which the metal to be coated passes down into the bath, the hood carrying a part extending down into the molten bath through the lower part of the oats closed, inlet openings for introducing a protective atmosphere into the hood at a point at some distance from the surface of the bath, the atmosphere moving in the opposite direction to the metal to be coated and substantially immobile at the surface of the bath, a container with cradles for heat exchange with the hot tub and with an upper opening completely and ballet coated with the hood and close to but above the surface of the hot tub, a device for introducing alkali metal into the container without the hood opening to the outside air and containing a further device in connection with the container for receiving the alkali metal. working in succession to close the latter device to the atmosphere in the container and Opposite the external atmosphere for the introduction of the metal and to block it from the external atmosphere ° eh open towards the container f Or the metal is deposited in the container whereby a substantially but atmosphere of alkali manga is immediately above the surface of the narrow metal bath Imre in the hood.

Apparatus according to claim 5, characterized in that the hood is terminated below a bell, that the lower part of the bell dips into the bath, that the hood and the bell serve as protection for the metal to be coated against the external atmosphere while it is being inserted into the ha- - - and that an open container for alkali metal Sr placed inside the watch is formed as a part of the cradle of the watch with inward and upwardly directed portions thereof, that the container extends around the inside of the watch and serves to mediate heat exchange between the molten bath and the alkali metal and that the container ning Sr placed in close proximity to the surface of the hat inside the watch.

7. Apparatus according to claim 5 or 6, characterized by a device for supplying in the hood near but above the clock an abrasive, non-oxidizing atmosphere containing Stoelaoln) 1949. Kungl. Bolan P. S.1,7orstcdt & Kner 400089