CN1011867B - Method and apparatus for continuous casting of metal band esp. of steel band - Google Patents

Abstract

In such a process of the present invention for the continuous strip casting of metals, the molten metal(1) is introduced in a regulated manner from a supply quantity into a crystallizer(4) and the cast strip or cast billet(5) is drawn out in a regulated manner with a thickness of 10 to 40 mm. In order, in the continuous casting of thin billets into the relatively narrow continuous-casting moulds for thin billets, to achieve a solidification which is as rapid and as uniform as possible over the cross-section of the thin billets, it is proposed that the molten metal(1) be introduced into the supply quantity with an overheating of between 3 and 10 DEG C, that this overheating energy first be discharged from the supply quantity, and that there be introduced into the crystallizer(4) molten metal(1) which has a total viscosity of the two-phase melt/crystal state of less than 300 Centipoises.

Description

Method and apparatus for continuous casting of metal band esp. of steel band

The present invention relates to the band continuous cast method and the equipment thereof of a kind of metal, especially steel.When using the inventive method, molten metal controlledly sprays into crystallizer and controlledly pulls out from storage container continuous casting band, its thickness is the 10-40 millimeter.

According to the relevant principle of physics, when people might satisfy the hot-rolled band material performance requirement, the strand compression ratio is reduced to minimum (greater than 3), the result makes the new technology of the producing the continuous casting band new development of having got back on this basis.

The conventional production lines of continuous casting steel billet (the about 200-300 millimeter of thickness) and continuous casting band is made up of roughing train, middle machine row and finishing mill line, and its compression ratio is greater than 30.All other production lines are section bar, and the compression ratio of seamless pipe and plate production line has but reached 3-10.For compression ratio from reducing to greater than 3 greater than 30, cancelled roughing train and middle machine row in the production line, also cancelled the part finishing mill line.So just produced the continuous casting new technology, it has shortened production line widely, has reduced the production cost that is transformed into hot-rolled band from the continuous casting band.

The prior art of continuous casting can be divided into following several method, and the whole bag of tricks all has its independent implication.In vertical continuous casting and horizontal casting, use diaphragm sometimes, then manage sometimes to make between strand and the horizontal casting mould to produce relative motion.When using portable metal pattern, below metal pattern, should be equipped with some to belt feeder, roll, chain and kindred organization.

Task of the present invention is: when the continuous casting thin stock, so molten metal was both solidified on the thin stock cross section rapidly and as far as possible equably if the used continuous casting of metals mould of thin stock is quite narrow.

Described task will be finished by following measures of the present invention.Molten metal is put the crystallizer that is made of two movable annular strips by controlledly watering in the memory, and controlledly pull out the continuous casting band, its thickness is the 10-40 millimeter, and from memory, will cross thermal energy earlier and derive, it is characterized in that: make the molten metal that pours into memory have 3-10 ℃ overtemperature, and molten metal poured into crystallizer, this moment, total viscosity number of molten metal and crystal two-phase section was less than 300 centipoises.Such viscosity can make thickness be 10-40 millimeter thin stock cross section cooling rapidly and cooling evenly, therefore the melting tank up to several meters commonly used in the past also can save.According to this way, poring rate has improved, and the productivity ratio of correspondingly solidifying strand also significantly improves.About how to manage the thermal energy of crossing that pours into molten metal in the memory is derived, and guarantee that molten metal pours into before the crystallizer or makes wherein comprised some crystal when cast, this imagination can have various embodiment.

The present invention imagination can controlledly derive the thermal energy of crossing in the storage container by the forced convertion of molten metal.Here said forced convertion for example can realize by stirring molten metal.

Should consider the viscosity of molten metal this moment, because the molten metal in the storage container, or the molten metal between storage container and crystallizer is cooled, and the viscosity number of molten metal and crystal two-phase section has reached the 1-5 centipoise.

Molten metal in the memory is subjected to the effect of certain pressure, and this crystallization to molten metal in the memory is beneficial.The viscosity of molten metal is also therefore big than the viscosity of pure metal, and it is poured into crystallizer forcibly.

In addition, in order to discharge thermal energy, also can consider to make and gather materials the area of chamber in the intermediate distributary jar greater than the area of molten metal memory.

Another kind of present device embodiment is that agitating device is made of solenoid.

Also have a kind of present device embodiment: heater is made of the inductive electromagnetic coil.

Also cooling device and heater can be combined.

The embodiment of the invention as shown in drawings, and details are as follows:

Fig. 1, first embodiment, the vertical section of band continuous casting installation for casting.

Fig. 2, second embodiment, vertical section such as Fig. 1.

Fig. 3, the 3rd embodiment (Zuo Bantu) and the 4th embodiment (right half figure), vertical section such as Fig. 1 and Fig. 2.

Fig. 4, the 5th embodiment, vertical section such as Fig. 1 to Fig. 3.

Molten metal 1(is molten steel for example) from a container (annotating in addition among the figure) that stores molten metal.The container of storage molten metal can be made of teeming ladle or tundish, and cast gate 2 is equipped with in its bottom, and molten metal can flow into an auxiliary intermediate distributary jar 3 by storage container, also can directly pour into crystallizer 4.

Crystallizer 4 shown in Figure 1 is made of a film 6 that is attached to strand 5 broadsides, film 6 be shaped as banded 6a.It can be made by different materials, and the film metal of can drawing materials then can be considered to make film with aluminium strip or steel band.But film 6 also can be a ceramic material, and for example thickness is 0.1 millimeter and has the ceramic material of high thermal conductivity.Can consider in addition make film 6 with the palpus epitaxial of glass fibre membrane carbon fiber and carbon monocrystalline, obviously, film 6 also can mix above-mentioned material and make.The equal ability variations in temperature of above-mentioned material and higher thermal conductivity is arranged.Can consider in addition the metal tape of film 6 with support film 6 used, metal tape does not directly contact the strand 5 that aqueous molten metal 1 and appearance have been solidified.In this case, film 6 can prevent bonding between chilled metal tape and the hot-cast base 5.

In principle, use film 6 can save the vibration of crystallizer 4.If about 1500 ℃ of molten metal (molten steel) temperature, and the about 10-40 millimeter of slab thickness, so, how molten metal is poured into the such problem of narrow metal pattern, to solve by the following method of the present invention: intermediate distributary jar 3(or teeming ladle, tundish or the like) area is bigger, flows to cast 7 places, cross section molten metal 1 was discharged thermal energy in intermediate distributary jar 3 after again and cools off fully.The embodiment of Fig. 1 has represented this continuous cast method: molten metal 1 is poured into the funnel-form inlet 8 that is made of film band 6a, can occur a quasi-steady state convex surface (in by figure shown in the radius arrow) at inlet 8 places.Intermediate distributary jar 3 distributes molten metal along the metal tape width here.The effect of diversion cans outlet 10 is to be used for producing quasi-steady state convex surface 9, and its width is preferably less than ingot casting thickness 11.Convex surface 9 and funnel-form the enter the mouth molten metal at 8 places and the mixture of crystal, will promptly flow to cast cross section 7(is ingot casting thickness 11) locate, temperature loss therebetween can be ignored; The mixture of molten metal and crystal is sufficiently cooled at cast 7 places, cross section, forms solidification layer 5a and 5b.Because the protection of slag blanket, molten metal 1a generally can not reoxidize.

Cross thermal energy according to molten metal 1 quantity difference, available cooling device 50 or agitating device 54 are derived.Bath surface 51 also had thermal energy, and its thermal energy of crossing discharges on liquidus curve 52; Then increasing crystal can occur on solidus 53, promptly ingot casting 5 promptly becomes curdled appearance.Cooling device 50 and agitating device (stirring with solenoid) 54 also can use in order by other of mark among the figure.In addition, if necessary, also solenoid 54 can be used as heater, will use the relevant technologies of electronics this moment.Among second embodiment (Fig. 2), molten metal 1 can export 10 by diversion cans and directly pour into crystallizer 4.Diversion cans outlet 10 directly is on the position of cast gate 2 in this example, and metal bath 1 flows into funnel 8 under pressure △ p effect, subsequently cooling (type of cooling as described above).Intermediate distributary jar 3 of no use in this example has just improved the position of cast gate 2.If molten metal 1 is pouring in vertically clamped moulds, so as long as under desired cooling condition, the quasi-steady state convex surface of being mentioned above producing 9 can think that then the position of cast gate 2 has been improved.

Above crystallizer 4, certain device 12 has been installed.Device 12 has outlet 10, can be by cast gate 2, also can be made of intermediate distributary jar 3.

Export 10 centring axis 13, film 6 is positioned on the crystallizer 4.Crystallizer 4 in this example except by the metal tape 6a, also is made of pair of columnar roller 14 and 15.The length of column roller is corresponding with the strip width of being cast.Film 6 or metal tape 6a are close on the roller of column pair roller 14 or 15, and and roller between very close to each other.The adjustable in the horizontal direction direction of each roller in the pair roller 14 or 15 is shown in arrow among the figure 16, and different because of shrinkage factor and slab thickness 11 often need pair of rollers adjustment.In order to make inlet 8 be funnel shaped, film 6 following deflector rolls 17 should have many; Auxiliary guide roller 18,19 and 20 can make film 6 smoothly by a cooler 21.

Crossing thermal energy will derive by cooling device 50 or agitating device 54 at cast gate 2 places.Bath surface shown in the figure 51, liquidus curve 52 and solidus 53 are the same with afore-mentioned.The pressure reduction △ p of Zuo Bantu is bigger than right half figure's.

Among half figure of Fig. 3 left side, film 6 is promptly walked in the slit 22 between the sidewall 3b of intermediate distributary jar 2 in outlet 10.Film 6 is also walked in identical slit 22 among right half figure.Also have a difference in addition: the situation of film during through sidewall 3b and cast cross section 7 is different, and unexpected and film 6's mixture that this difference has caused molten metal 1 and crystal be cooled at this place) contact.Film 6 between the pair roller 14 and 15 is by cooling device cooling (among the figure two horizontal arrow shown in).

Metal tape 6a only keeps in touch with strand 5 on the part path 23 of strand process, and part path 23 is by roller diameter or by the distance decision between the roller.

Yet also film 6 can be contained on other the crystallizer 4, make crystallizer 4 support the time of strand 5 and the time lengthening that strand is cooled.Intermediate distributary jar 3 can move up or down to constitute slit 22.

The rotating speed of roller should adapt with casting rate Vg between the pair roller 14 and 15, also is Vg with the movement velocity that guarantees film 6.In addition, the used mark of cooling situation is same as aforementioned mark among the figure.As cooling device 50, agitating device 54, bath surface 51(crosses thermal energy), liquidus curve 52 and solidus 53.

Among Fig. 4, sidewall 3b can be wideer than cast cross section 7.Can prevent heat radiation too much with sidewall 3b, in order to avoid between liquidus curve 52 and solidus 53, more undesirable crystal number in molten metal 1, occurs.As shown in FIG., obviously also can use solenoid 54 heat supply again.

Claims (2)

1, the band continuous casting process of metal, especially steel, when using the method, molten metal is by controlledly pouring into the crystallizer that is made of two movable annular strips in the storage container, and controlledly pull out the continuous casting band, its thickness is the 10-40 millimeter, and from memory, will cross thermal energy earlier and derive, it is characterised in that:

Make the molten metal (1) that pours into storage container have 3-10 ℃ overtemperature, and molten metal (1) is poured into crystallizer (4), this moment, total viscosity number of molten metal and crystal two-phase section was less than 300 centipoises.

2, by the method for claim 1, it is characterized in that: the thermal energy of crossing in the memory is controlledly derived by the forced convertion of molten metal (1).

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