CN1072047C - Element of a continuous metal casting ingot mould with a copper or copper alloy cooled wall comprising on its external surface a metal coating,and method of coating - Google Patents

Element of a continuous metal casting ingot mould with a copper or copper alloy cooled wall comprising on its external surface a metal coating,and method of coating Download PDF

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Publication number
CN1072047C
CN1072047C CN97196281A CN97196281A CN1072047C CN 1072047 C CN1072047 C CN 1072047C CN 97196281 A CN97196281 A CN 97196281A CN 97196281 A CN97196281 A CN 97196281A CN 1072047 C CN1072047 C CN 1072047C
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silver
metal
wall
copper
electrolytic solution
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CN97196281A
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CN1225046A (en
Inventor
J-M·达马斯
J-C·卡托尼
C·阿里莱
G·斯蒂布尔
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Thyssen Stahl AG
USINOR SA
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Thyssen Stahl AG
USINOR SA
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B22CASTING; POWDER METALLURGY
    • B22DCASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D11/00Continuous casting of metals, i.e. casting in indefinite lengths
    • B22D11/04Continuous casting of metals, i.e. casting in indefinite lengths into open-ended moulds
    • B22D11/059Mould materials or platings
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D3/00Electroplating: Baths therefor
    • C25D3/02Electroplating: Baths therefor from solutions
    • C25D3/46Electroplating: Baths therefor from solutions of silver
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/10Electroplating with more than one layer of the same or of different metals
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/60Electroplating characterised by the structure or texture of the layers
    • C25D5/615Microstructure of the layers, e.g. mixed structure
    • C25D5/617Crystalline layers
    • CCHEMISTRY; METALLURGY
    • C25ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; APPARATUS THEREFOR
    • C25DPROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTION OF COATINGS; ELECTROFORMING; APPARATUS THEREFOR
    • C25D5/00Electroplating characterised by the process; Pretreatment or after-treatment of workpieces
    • C25D5/67Electroplating to repair workpiece

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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Metallurgy (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Electrochemistry (AREA)
  • Materials Engineering (AREA)
  • Organic Chemistry (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
  • Electroplating Methods And Accessories (AREA)
  • Moulds For Moulding Plastics Or The Like (AREA)
  • Coating With Molten Metal (AREA)
  • Electroplating And Plating Baths Therefor (AREA)

Abstract

The invention concerns an element of a continuous metal casting ingot mould with a copper or copper alloy cooled wall to be contacted with liquid metal and comprising on its external surface a metal coating, characterised in that the said coating consists of a silver plating. In a preferred embodiment, this wall is a cylinder hoop for a continuous casting machine of thin metal strips between two cylinders or on one single cylinder. The invention also concerns a method for coating with a metal plating the external surface of a copper or copper alloy cooled wall of an element of a continuous metal casting ingot mould, characterised in that a coating is effected by the deposit of a silver plating on said surface preferably by electrolysis. Preferably, the restoration of said silver plating is done by allowing a residual silver plating to subsist on said wall, and by effecting a re-silvering of said plating by placing said wall in cathode in an electrolysis consisting, for instance, of an aqueous silver cyanide solution, of an alkaline metal cyanide and of an alkaline metal carbonate.

Description

The copper or the metal continuous casting crystallizer parts of copper alloy cooling stave and the method for coating that comprise the metal plating on the outside surface
The present invention relates to the metal continuous casting crystallizer parts.Or rather, it relates to and comprises the crystallizer parts that have at the coating of its copper or copper alloy wall outside surface, form the method for this coating and in this coating wearing and tearing back to its method of being recovered, as described in metal starts from as the process of setting of steel in the crystallizer.
Metal carries out in no base plate crystallizer such as the continuous casting of steel.On described wall, the be cooled internal recycle of agent such as water of crystallizer is forced cooling.Liquid metal contacts with the outside surface of described wall.And begin thereon immediately to solidify.Described wall must be made by the fabulous material of heat-conductive characteristic, so that they can fully lose the heat on the metal at short notice.Generally speaking, a kind of alloy of copper or copper for example contains the copper alloy of chromium and zirconium, is suitable for use as this purpose.
Usually, the surface of these walls that contact with liquid metal, plating has a nickel dam on it, and the original depth of described nickel dam can reach 3mm.This nickel dam just forms a protective layer of copper, copper is unlikely be subjected to the effect of excessive thermal stress and mechanical stress.
In the crystallizer use, described nickel dam can wear and tear.Therefore, must adopt residual thickness is removed fully, and then the method for deposition one deck new nickel dam periodically recovers nickel dam, and that the copper wall that such cost of resuming work comparison has been worn and torn is done to change fully is much lower.Usually, in case nickel layer thickness reduces to about 0.6mm, will recover it.
Therefore, the deposition of this nickel dam on crystallizer wall is an important preparatory stage before this type of casting machine uses, and, simultaneously to expense, use properties with and the adhesion quality be optimized very important.Especially be all the more so for the casting machine of ferrous metal product of ribbon form of several mm for being used for cast thickness, such ferrous metal product is not need to carry out subsequently hot rolled again.This class casting machine that is at present in the performance history comprises a crystallizer, this crystallizer constitute two around the axle that the is in horizontal attitude separately rolls of rotation in opposite direction, and two refractory side plates that are pressed in the roll end.These roller diameters can reach 1500mm, and its width is roughly 600-1300mm for this experimental installation.Yet in the long term, described width must reach 1300-1900mm, to satisfy the requirement of industrial equipments productivity.These rolls comprise a steel core, are fixed with the roller shell of copper or copper alloy round described steel core, and roller shell is by the cooling of the recirculated water between steel core and the roller shell, or, cooled off by the recirculated water of roller shell inside more at large.Must use the outside surface of the described roller shell just of nickel plating, perhaps be easy to expect, because the shape and size of this roller shell, its plating will be more more complicated than the plating of traditional continuous casting crystallining wall, tradition continuous cast mold or make by tube element, or be assembled by flat board, and its size is much smaller.For the roller shell of casting roll, the method for nickel deposited is optimized is even more important, its reason is:
-owing to there is not subsequently hot rolling, so may from the angle of the finished product, can have the danger of redhibitory because of the surface imperfection due to nickel dam second-rate on the band;
-since before roller shell uses the quantity of nickel deposited thereon, much more very and the quantity of the beginning of resuming work of the nickel dam nickel that the time will remove is all bigger, and this says and mean, need to consume a large amount of electric energy and need spend the time, especially when nickel plating, the typical time is several days.
The work that nickel is removed from the roller shell fully must be carried out before nickel dam is resumed work, and this removal work also is very important.On the one hand, the completeness of removal is determining subsequently to want quality, the especially nickel dam of sedimentary nickel dam and the adhesivity between roller shell to a great extent because prove, deposit one very difficult with the good new nickel dam of old nickel dam adhesion.On the other hand, the removal work of described nickel must be carried out under the copper that does not make roller shell has the condition of a large amount of losses, and roller shell is a kind of extremely expensive component, and must prolong as much as possible its work-ing life.Especially in fact this requirement of back has been got rid of and has been adopted pure mechanical means to carry out the removal of nickel, because the precision of this method is not enough to guarantee when nickel is removed fully, so that the whole lip-deep copper of roller shell is protected.
Other castmethod be by deposition liquid metal on the periphery of the roll of single rotation cast also will be thinner sheet metal strip, described roll may also be made up of a steel core and a copper cooling roller shell.Problem in the plating roller shell surface of just having described exists in identical mode at this.
The purpose of this invention is to provide a kind of copper or the outside surface of copper alloy wall method of carrying out plating to continuous cast mold, this method is more more economical than the common method at described surface deposition nickel dam generally.Method of the present invention should also can make the wall of crystallizer have suitable with deposited nickel layer at least performance and quality.Described method also should comprise carries out the periodically method of recovery to described surface.This method should especially be suitable for the plating of the roller shell of double-roll type or mono-roller type casting machine.
For this reason, theme of the present invention is parts on the crystallizer used of metal continuous cast, it comprises the cooling stave of copper or copper alloy, and described wall is in order to contact with liquid metal and layer of metal coating is arranged on the outside surface of wall, it is characterized in that described coating is made up of one deck silver layer.In preferred an application of the present invention, described wall is the roll sleeve of the casting machine of a double-roll type that carries out metal sheet band or mono-roller type continuous casting.
Theme of the present invention also comprises the method for metal plating layer on a kind of copper of parts at metal continuous casting crystallizer or the copper alloy cooling stave outside surface, it is characterized in that this coating obtains by deposition one deck silver on described surface, preferably adopts electrolytic method.Copper that described electrolysis process is used to expose or copper alloy wall, and comprise the following steps:
-described wall is cleaned;
-described the wall of pickling in the oxidizing acid medium;
-described wall is carried out pre-silver-plated processing, this wall places a kind of electrolytic solution with the thick silver layer of the deposition several μ m of one deck as negative electrode, and described electrolytic solution contains the aqueous solution of silver cyanide and a kind of alkali-metal prussiate;
-described wall is carried out silver-plated processing, this wall places a kind of electrolytic solution as negative electrode, and described electrolytic solution contains silver cyanide, a kind of alkali-metal prussiate, the solution of a kind of alkali-metal oxyhydroxide and a kind of alkali-metal carbonate.
The present invention also is included in silver layer consumption later on to its method of being recovered.Preferably, the recovery of described silver layer is by having left over remaining silver layer and having realized with silver-colored described remaining silver layer is heavily plated on described wall, heavy electroplating method is as negative electrode with described wall, and place a kind of electrolytic solution, this electrolytic solution for example contains, the aqueous solution of silver cyanide, a kind of alkali metal cyanide and a kind of alkali-metal carbonate.Scheme as an alternative, the method that silver layer is recovered can comprise the part or all of removal of silver and weigh silver-plated processing, wherein Yin part or all of removal is by placing a kind of electrolytic solution to carry out as anode on described wall, described electrolytic solution is based on nitric acid, and contain a kind of inhibiter of copper, and the silver-plated processing of the weight of described wall or remaining silvering, by placing a kind of electrolytic solution to carry out as negative electrode on described wall, this electrolytic solution is made up of a kind of aqueous solution that comprises silver cyanide, a kind of alkali-metal prussiate and a kind of alkali-metal carbonate.
As should understanding, the present invention at first is to replace being used for traditionally forming with silver the nickel of coating on the copper wall outside surface of the continuous cast mold of metal such as steel.Solid-state silver is counted as precious metal, and is opposite with the initial idea that is produced thus, method of the present invention have many economically advantage and technical be fully feasible.When using a kind of solution that contains alkaline cyanide to carry out electrolytic process when silver-plated, situation is all the more so.Verified such plating bath can form silvering on copper, the use properties of this coating is suitable for protecting the wall of continuous cast mold fully.
Also the special methods to this plating crystallizer surface is described and has required right, this method comprises a silver-plated step, and, can selectively comprise one arbitrarily when requiring coating to the crystallizer surface of wearing and tearing to recover, the step that silver is removed from described surface.The removal of described silver can be a part, and when coating is nickel dam, in fact must from copper nickel be removed fully, and can there be the danger of the copper on the loss part wall in this.Silver-plated and removal silver can adopt electrolytic method to carry out.Revert to metallic state again on the silver cathode of the silver that from roller shell, is removed silver removal reactor.Described negative electrode can be then as the anode cycle applications in the silver plating reaction device.As another kind of method, the removal of silver can adopt method chemistry or machinery to carry out at least in part.
Now, the present invention will obtain describing in detail in one of its embodiment, and this method is used to carry out on the plating of the copper of casting machine of the double-roll type of steel or mono-roller type continuous casting or copper alloy roll sleeve.But obvious described example can be changed the occasion with the crystallizer that copper or copper alloy wall are arranged that is used for other type at an easy rate, for example, is used for crystallizer slab, bloom or continuous-casting of steel billet, that fixation wall is arranged.Be clear that very that also method silver-plated or removal silver can be used other various electrolysis processs, for example brush plating or spraying coating also can use the electrolytic solution the plating bath that provides in example.Also the copper wall can be completely infused in the silver plating liquid, in this case, the present invention can be used for continuously or the roller shell of intermittent type rotation, or roller shell keeps static and electrolytic solution is forced to circulation.
Usually, new roller shell is as general as hollow cylinder, by copper or copper alloy, makes as copper-(1%) chromium-(0.1%) zirconium alloy.Its external diameter, for example about 1500mm, length equates with the width of the band that will cast, promptly about 600-1500mm.Can provide, its thickness can be about 180mm, and still, roller shell thickness especially should be done local the change according to the method for being taked that roller shell is fixed on the roller core.There is passage to pass in the roller shell, a kind of refrigerant, such as water, the passage of when casting machine uses, flowing through.
For in the work that will describe, be easier to carry out the operation of roller shell, at first roller shell is fixed on the roll shaft.Just by this way, before it was installed on the roll roller core, roller shell was handled station from one and is transported to another processing station.Handle station in silver-plated/each of workshop of removing silver and include and contain a kind of groove that is suitable for finishing the solution of a given step in the processing, described axle might be placed groove above, make the axle of axle be in horizontality, and make axle center on its rotation.Like this, just being immersed in the solution of roller shell than lower part, the combination of live spindle/axle sleeve just can be handled (need be appreciated that roller shell is generally when carrying out this same processing, to rotate several circles such as 10 rev/mins speed roughly) to whole roller shell.For avoiding the roller shell exposed portions serve to be polluted or passivation by ambiance, handle station at these, adopt a kind of equipment also to come in handy to roller shell exposed portions serve sprinkling treatment soln.For this purpose, also it is contemplated that to make the ambiance inerting such as argon gas, and/or the system that a pair roller cover carries out galvanic protection is installed by rare gas element.Yet, except this possible method, also can take measures to coating bath, make it allow roller shell all to immerse wherein, like this, the method for this splash or inerting just becomes and there is no need.
Exposed roller shell (for the first time to new roller shell, or to the copper surface when roller shell of exposed wearing and tearing has carried out silver-plated processings) at first, preferably adopts the mode of polishing that mechanical pretreatment is carried out on its surface.Then, in alkaline medium, carry out matting, its objective is and remove the lip-deep organism that contamination may be arranged it of roller shell.Cleaning is roughly to carry out under 40-70 ℃ the hotter temperature, 15 minutes time, next water flushing.This process can substitute with the electrolytic cleaning step, perhaps replenished, electrolytic cleaning can obtain also will be higher surface quality.
Next step is to carry out pickling in a kind of acidic medium of oxidisability, its objective is and removes oxide on surface, guarantees again simultaneously to have only that the roller shell of small thickness is dissolved falls.For reaching this purpose, employed pickle solution is that for example, the aqueous sulfuric acid of 100ml/l wherein before each the use, add 30% superoxol or another kind of peroxide solutions 50ml/l.Also may use chromic acid solution, the existing acidity of this compound has oxidisability again.When the temperature of electrolytic solution is 40-55 ℃, the pickling effect the best in the acid medium of oxidisability.In the roller shell of rotation hot water flow is circulated helps keeping this temperature at the interface through passage.This process continues about 5 minutes, and then the water flushing.
Afterwards, the shinny processing of carrying out the roller shell surface is more favourable, preferably uses the sulphuric acid soln of 10g/l, to avoid the roller shell surface passivation.
The time of above-mentioned whole preparation property work of being carried out before silver-plated, be no more than 30 minutes in principle.
Pre-silver-plated processing, it carried out before silver-plated, and purpose is to set up a kind of electrochemical conditions to be used to prevent that silver is replaced by copper during silver-plated, and this displacement is unfavorable for the adhesion of silvering.When roller shell is not by fine copper but by copper-chromium-when zirconium alloy was made, pre-silver-plated processing was particularly useful.Pre-silver-plated processing continues 4-5 minute, preferably carries out in envrionment temperature.Roller shell places a kind of electrolytic solution as negative electrode, and this electrolytic solution contains sodium cyanide (about 50-90g/l) and the aqueous solution of the silver cyanide (30-50g/l) that fully dilutes with dissolution of metals.Also can use potassium cyanide (65-100g/l) to replace sodium cyanide.Pre-employed electrolytic solution silver-plated the treatment stage, its composition, such just as will be seen, qualitative comparable with silver plating liquid, rinse stage in the middle of this fact might be exempted.And, the waste water that is produced by silver-plated post-flush is utilized, described waste water may recycle in pre-silver plating liquid very expediently.Cathode current density is 4-5A/dm 2, might use one or more soluble anodes (being made from silver) or insolubility anode (for example by Ti/PtO 2Or Ti/RuO 2Make).Using under the insolubility anodic situation, the free prussiate is when being converted into carbonate and separating out ammonia, and itself just is damaged.Therefore, be necessary that periodic replenishment adds the free prussiate in electrolytic solution, the flushing after silver-plated easily of described prussiate is handled the waste water that is produced and is removed, described pre-silver-plated processing might be at the silver layer of several micron thickness of roller shell surface deposition (for example, 1-2 μ m), again sour settling that may be remaining after the shinny processing is removed simultaneously.Then, roller shell just is transported to silver-plated station as quickly as possible without flushing, goes up existing one deck prussiate film to utilize its surface, and this film can protect the roller shell surface that passivation does not take place.
Silver-plated processing is carried out in a kind of electrolytic solution, and this electrolytic solution based on the aqueous cyanide solution of sodium and silver, wherein adds excessive free hydrogen sodium cyanide basically.But described electrolytic solution also can be made up of the potassium that adds excessive potassium hydroxide and the mixture of the prussiate of silver.Salt of wormwood also can add.A classical group of described plating bath becomes:
-AgCN:115-150g/l;
-KCN:215-250g/l;
-KOH:30-40g/l;
-K 2CO 3:10-15g/l。
Optimum treatmenting temperature is 40-45 ℃.
For making the anode uniform corrosion, salt of wormwood is essential.It also can replace with yellow soda ash, but shortcoming is that yellow soda ash solubleness is lower.Potassium hydroxide available hydrogen sodium oxide replaces.They guarantee the electroconductibility and the silver ions existence anion complex (Ag (CN) wherein of electrolytic solution 4 2-) stability.Silver-plated processing generally adopts direct supply to carry out, and direct supply can substitute with the transient current source easily, so that can increase the crystalline degree of refinement.Crystallization also can be adjusted easily by the temperature that reduces roller shell/electrolyte interface, for example, uses the passage internal recycle of cold water in roller shell.In this case, silver-plated electrolytic solution is thermal source and roller shell is a low-temperature receiver.Set up a thermograde thus, like this, the interface just has higher activation overpotential, and this helps the increase of coating hardness.
As described in the described example (from this point, example is not limited only to this), one or several anodes are soluble anodes, and such anode contains the argent of ping-pong ball or any other form by one or more such as the basket titanium anode of silver bullion is formed.These basket titanium anodes use as the electrode of dimensional stabilizing, and the shape that their shape and roller shell immerse part is complementary, thereby makes that the distribution of cathode current density on roller shell is very even.Because the anode-cathode distance does not change under the described conditions, basket shape anode just makes the current density on the negative electrode remain unchanged.
If roller shell can not be fully immersed in the electrolytic solution, then recommend to the utmost to the surface that roller shell does not immerse part and constantly spray same electrolytic solution, or use rare gas element to make not immerse the part inerting.Take this mode, can avoid the passivation of fresh silver-plated surface, passivation is unfavorable for that coating has good adhesive power and cohesion.For the same reason, also recommend when transporting roller shell between pre-silver-plated station and silver-plated station, the pair roller cover carries out splash or makes the roller shell surface inertnessization.It is contemplated that also the pair roller cover carries out galvanic protection.In any case transporting all of roller shell will be carried out as early as possible.
Might or under fixed voltage or under fixed current density, carry out electrolysis treatment.When electrolysis is at the voltage of about 10V and about 4A/dm 2Current density under when carrying out, approximately 5-8 days time (depending on that also roller shell is immersed in the degree of depth in the plating bath) can obtain the deposited silver layer of the thick 3mm of reaching.Then, roller shell is unclamped from bolster, prepare to be contained on the roller core, so that after silver layer surface being carried out possible final finishing processing, form the roll that uses in the casting machine.The finishing of silver layer surface is handled, and for example adopts shot-peening, laser machining or other any technology so that the surface has definite roughness.As on record, such finishing purpose is to make the heat exchange condition the best between roller shell and frozen metal.
In use, silver layer suffers erosion and mechanical wear, and this causes silver layer constantly to consume.Between twice castingprocesses, the roller shell surface must be cleared up, and, silver layer can, at least every now and then carry out slight machining, purpose is to improve inhomogeneous that wearing and tearing are caused, and this inhomogeneous meeting suffers damage the homogeneity of thermomechanical property in the whole roller shell surface range.As in case of necessity, that the roller shell surface recovery is also very important to initial roughness.When the mean thickness of silver layer on the roller shell reached a preset value, this value generally was estimated as 1mm, and roller shell is just stopped using and taken off to roller.Before the silver layer that pair roller puts recovered, possible pair roller cover carried out the removal fully of silver or only part removal.For this reason, roller shell can be fixed on again silver-plated during on the axle as supporting, if silver is removed fully, next step is exactly to adopt above-mentioned whole technological process that silver layer is recovered.
There is several method to be available for users to select to carry out the removal of silver.Pure chemistry method removal silver is possible, but employed reagent should only dissolve silver and should not make the copper matrix be subjected to obvious erosion, and only part silver is removed the very difficult control admirably that realizes.Another method that silver completely or partially can be removed is an electrolytic process, reason be copper and silver the standard potential obvious difference (for hydrogen electrode, be respectively 0.3V and-0.8V).This also is suitable for making the copper-chromium-zirconium alloy of roller shell.In this case, as anode, place suitable electrolytic solution that the dissolving of silver just can take place roller shell, usually, described electrolytic solution is based on nitric acid, and contains a kind of inhibiter of copper, as phosphate ion.One is shortened silver and removes the machinery that the method for process time is the silver that carries out in advance and remove, and its objective is the remaining thickness that reduces silver layer but does not touch copper.The advantage of this processing is to make silver thickness evenly and again various surface impurities to be removed (especially metal remnant), and these impurity can delay the dissolved starting point in the part.This will be avoided occurring a kind of like this situation, that is: at some regional silver during still in dissolving, and in other zone, copper exposes out.
Yet the weak point that electrolytic process is removed silver is that it requires to add a kind of particular solution, this solution, for toxic reason, with roller shell silver-plated/silver removes the workshop and uses other method that contains cyanide solution incompatible.
Therefore, the inventor recommends to adopt in silver plating liquid direct silver plated method to recover silver-colored bottom (employed plating bath when the preferably above-mentioned first time is silver-plated) on the roller shell, and does not require remaining silver-colored bottom is removed fully or almost completely.A step like this is possible, because be easy on Geju City silvering new silver layer of electrochemical deposition and obtain the good adhesion of new layer and old interlayer, and this is impossible for nickel.On the one hand, this has obviously simplified the material processing process in roller shell finishing workshop, and on the other hand, this has also shortened the servicing time of roller shell, thereby has also just shortened the out of use time of roller shell.And, replenish silver-platedly, as the inventor proposed, there is not the common caused defective of removal metal process, particularly in the removal of nickel, because silver plating solution has alkalescence in essence by other form.This alkalescence, in fact, as a kind of means that make the passivation of silver-plated station substructure nature, if this substructure is made by uncoated steel.Another advantage of the present invention is to make the substructure of described steel carry out anodizing anything but, and the anodizing meeting increases their corrosion, and harmful to their life-span.Direct silver plated another advantage, compare with silver plated again method after almost completely electrochemistry is removed with silver, be in the removal process of silver, can avoid silver to dissolve fully at some priority area (as the edge of roller shell), whole dissolvings of this priority area can cause the part of copper exposed.In addition, this also makes and there is no need to carry out pre-silver-plated this step again.At last, under the consoluet condition of avoiding on the roller shell of copper, replenish the silver-plated roller shell surface that prevents and suffer erosion, thus the life cycle that has prolonged roller shell.Replenish the slight machining of the silver-plated silver layer that weares and teares before, fall so that its thickness uniformity also will be harmful to the Impurity removal of adhesive power between new silver layer and old silver layer.
Therefore, remove the workshop with the nickel plating/nickel of roller shell and compare, the feature of the silvering shop of roller shell is the equipment that it must not comprise the coating of chemistry or electrochemical dissolution wearing and tearing.Therefore its fabrication cost is lower.The enforcement of process also is more economical, because silvering shop consumes under the current density of less electric weight-same, silver is especially that to be higher than nickel triple speed deposition-reason silver is monovalent and nickel is divalence.Yet this advantage is fallen by partial offset, and reason is for making silvering and nickel coating suitable to the thermal protection performance of roller shell, must sedimentary silver thickness be two times of corresponding nickel layer thickness approximately.But then, compare with thin nickel roller shell, thicker silver layer pair roller cover has better mechanical protection effect.As for reagent, in fact the cost of employed silver salt, is compared with used nickel salt in the traditional crystallizer wall nickel plating method, and difference is little.Thereby, generally, the cost of silvering than the cost height of nickel coating not what, and primary is that the reparation of the casting roll roller shell after the wearing and tearing is faster and more economical.
The waste water that contains prussiate, the especially wash-down water that give off from the workshop can use Javelle water to handle, so that prussiate is destroyed.Because Javelle water is easy to electrolytic preparation, therefore might handle continuously the waste water of this slight cyaniding with electrolytic method: argent is reclaimed at negative electrode, and prussiate is directly destroyed on the anode of dimensional stabilizing, and becomes volatile salt.Therefore, for the environmental problem of using cyanide salt to cause, can find simple and the not high terms of settlement of expense.
The present invention is particularly suited for the finishing of roll sleeve in the double-roll type of steel or the mono-roller type continuous casting installation for casting, because these part dimensions are big and cost is high.Given this, it is very important to prolong its life-span as far as possible.Yet in the nature of things, the present invention can be used for handling the wall of the continuous cast mold of the copper of Any shape and size or copper alloy, and the wall of described crystallizer is used for casting any metal, and this metal is in liquid state, can contact with silver under casting condition.

Claims (10)

1. the parts that are used for the crystallizer of metal continuous cast comprise the cooling stave of copper or copper alloy, and described cooling stave contacts with liquid metal, and a metal plating is arranged on its outer surface, it is characterized in that described coating is made up of silver layer.
2. according to the crystallizer parts of claim 1, it is characterized in that described wall is the roll sleeve of the casting machine of a double-roll type that carries out metal sheet band or mono-roller type continuous casting.
3. according to the crystallizer parts of claim 1 or 2, it is characterized in that described silver layer deposits with electrolysis process.
4. the method for metal plating layer on the outside surface of the copper of metal continuous casting crystallizer parts or copper alloy cooling stave, it is characterized in that this coating adopts electrolysis process to obtain by deposition silver layer on described surface, and copper that described electrolysis process is used to expose or copper alloy wall, and comprise the following steps:
-described wall is cleaned;
-described the wall of pickling in the oxidizing acid medium;
-described wall is carried out pre-silver-plated processing, this wall places a kind of electrolytic solution with the thick silver layer of the deposition several μ m of one deck as negative electrode, and described electrolytic solution contains the aqueous solution of silver cyanide and a kind of alkali-metal prussiate;
-described wall is carried out silver-plated processing, this wall places a kind of electrolytic solution as negative electrode, and described electrolytic solution contains silver cyanide, a kind of alkali-metal prussiate, the solution of a kind of alkali-metal oxyhydroxide and a kind of alkali-metal carbonate.
5. according to the method for claim 4, it is characterized in that described method also comprise one pickling and pre-silver-plated between described wall is carried out shinny processing step.
6. the method that the silvering on the outside surface of the copper that is deposited on the metal continuous casting crystallizer parts or copper alloy wall is recovered, it is characterized in that remaining silver layer is retained on the described wall, and, by described wall is placed a kind of electrolytic solution that contains silver salt as negative electrode, with silver described silver layer is heavily plated, described electrolytic solution contains the aqueous solution of silver cyanide, a kind of alkali-metal prussiate and a kind of alkali-metal carbonate.
7. according to the method for claim 6, it is characterized in that, heavily plate before the processing, residual silver layer is only carried out slight machining, rather than it is removed fully with silver.
8. the method that the silvering on the outside surface of the copper that is deposited on the metal continuous casting crystallizer parts or copper alloy wall is recovered, it is characterized in that: the part or all of removal of silver is by placing a kind of electrolytic solution to carry out as anode on described wall, described electrolytic solution is based on nitric acid, and contain a kind of inhibiter of copper, and, its feature also is the silver-plated processing of the weight of described wall or remaining silvering, by placing a kind of electrolytic solution to carry out as negative electrode on described wall, this electrolytic solution is by a kind of silver cyanide that comprises, the aqueous solution of a kind of alkali-metal prussiate and a kind of alkali-metal carbonate is formed.
9. according to the method one of among the claim 4-8, it is characterized in that, silver-plated or heavy silver-plated during, between described wall and electrolytic solution, produce thermograde, described thus wall is cooled off.
10. according to the method one of among the claim 4-8, it is characterized in that silver-plated or heavy silver-plated during, employed is a kind of transient current source.
CN97196281A 1996-07-11 1997-06-26 Element of a continuous metal casting ingot mould with a copper or copper alloy cooled wall comprising on its external surface a metal coating,and method of coating Expired - Fee Related CN1072047C (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR9608658A FR2750903B1 (en) 1996-07-11 1996-07-11 ELEMENT OF A LINGOTIERE FOR THE CONTINUOUS CASTING OF METALS, COMPRISING A COOLED WALL IN COPPER OR COPPER ALLOY HAVING A METAL COATING ON ITS EXTERNAL SURFACE AND METHOD FOR COATING THE SAME
FR96/08658 1996-07-11

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CN1072047C true CN1072047C (en) 2001-10-03

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KR100760731B1 (en) * 2000-03-03 2007-10-04 엘렌 토르페 패트리샤 Bulbous valve and Stent for Treating Vascular Reflux
EA008676B1 (en) * 2005-08-22 2007-06-29 Республиканское Унитарное Предприятие "Белорусский Металлургический Завод" Method for applying two-layer galvanic coating on copper sleeve and crystallizer plate
DE202009013126U1 (en) * 2009-09-29 2009-12-10 Egon Evertz Kg (Gmbh & Co.) Mold for continuous casting
CN102672437B (en) * 2012-06-04 2014-07-30 无锡市三方轧辊有限公司 Processing technology for recycling hot-rolled aluminum plate mill roll
EP2942168B1 (en) 2014-05-09 2018-02-07 Fiskars Finland Oy Ab Chopping aid
CN107254697B (en) * 2017-06-06 2020-02-14 秦皇岛瀚丰长白结晶器有限责任公司 Gradient distribution process and electroplating device for nickel-cobalt alloy plating cobalt of crystallizer copper plate

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DE2450937A1 (en) * 1974-10-23 1976-05-06 Schering Ag Cyanide free alkaline galvanic pre-silver-plating bath - contg. sulphite and or carbonate and soluble silver cpd.
JPS5570452A (en) * 1978-11-20 1980-05-27 Nishio Metaraijingu:Kk Continuous casting mold
DE3211199A1 (en) * 1982-03-26 1983-09-29 Egon 5650 Solingen Evertz Process for nickel-plating gravity-die walls
EP0315523A1 (en) * 1987-11-05 1989-05-10 Societe Nationale D'etude Et De Construction De Moteurs D'aviation "Snecma" Electolytic process for plating a thin silver layer, and its use in races

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2450937A1 (en) * 1974-10-23 1976-05-06 Schering Ag Cyanide free alkaline galvanic pre-silver-plating bath - contg. sulphite and or carbonate and soluble silver cpd.
JPS5570452A (en) * 1978-11-20 1980-05-27 Nishio Metaraijingu:Kk Continuous casting mold
DE3211199A1 (en) * 1982-03-26 1983-09-29 Egon 5650 Solingen Evertz Process for nickel-plating gravity-die walls
EP0315523A1 (en) * 1987-11-05 1989-05-10 Societe Nationale D'etude Et De Construction De Moteurs D'aviation "Snecma" Electolytic process for plating a thin silver layer, and its use in races

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PT910489E (en) 2000-10-31
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ZA975970B (en) 1998-01-30
ATE192951T1 (en) 2000-06-15
WO1998002263A1 (en) 1998-01-22
EP0910489A1 (en) 1999-04-28
RU2181315C2 (en) 2002-04-20
RO119994B1 (en) 2005-07-29
KR20000022396A (en) 2000-04-25
CZ6499A3 (en) 1999-10-13
EP0910489B1 (en) 2000-05-17
JP2000514361A (en) 2000-10-31
FR2750903A1 (en) 1998-01-16
PL331180A1 (en) 1999-06-21
AU3448897A (en) 1998-02-09
SK299A3 (en) 1999-05-07
DE69702064T2 (en) 2001-01-11
DK0910489T3 (en) 2000-10-09
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BR9710229A (en) 1999-08-10
TR199900041T2 (en) 1999-06-21
DE69702064D1 (en) 2000-06-21

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