DE1132297B - Wrapping for the pouring stream when the chill casting falls - Google Patents

Description

GERMAN

PATENT OFFICE

D 33725 VIa / 31c

REGISTRATION DATE: JULY 7, 1960

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL: JUNE 28, 1962

The invention relates to the falling chill casting of iron alloys, namely to a mode of operation in which the pouring stream sticks at a certain distance from one in the mold arranged shell is surrounded. The purpose of the envelope is in particular to avoid air oxidation the pouring stream, the splashes it causes on the inner surface of the mold, and the spread the impurities in the weld pool carried along by the pouring stream.

The last two tasks require that the shell in the weld pool constantly with a certain Depth, which is determined by the force of the pouring stream. Because the shell on the top the mold is firmly arranged, it must inevitably from below with the rise of the poured melt are continuously destroyed. As a result, it is very difficult if not impossible to keep the minimum immersion depth from the beginning to the end of the casting with certainty, especially since the temperature and nature of the weld pool as well as the destructive effect of the pouring stream in the course of filling the mold and even more from a mold to change another.

In summary, it can be stated that the shell changes too many and too strongly in the course of the casting Conditions are subject to all these conditions being taken into account with certainty could be. The invention aims to eliminate the previous disadvantages. object of the invention is a sheathing device for the pouring stream in falling chill casting, in which the shell with its upper part on the mold or possibly on the during casting in Relation to the mold fixed casting container is attached. The case is combined with a at least partially incombustible auxiliary piece, which represents a float and on the lower part the shell is arranged with such play that it slides without friction along the shell.

The weight of this floating auxiliary piece remains completely constant during the casting process. Consequently it is raised as the pouring proceeds, according to the Archimedean Principle with a constant part immersed in the weld pool. In this way a constant level of protection is guaranteed below the melt level around the pouring stream, regardless of the irregularities which occur in the destruction of the actual envelope appear.

Sheathing for the pouring stream
with falling chill casting

Applicant:

Henri Jean Daussan,
Metz / Moselle (France)

Representative: Dr. Lotterhos and Dr.-Ing. Lotterhos, Frankfurt / M., Lichtensteinstr. 3

Claimed priority:

France of July 10, 1959 and May 10, 1960
(No. 799 905 and No. 826 735)

Henri Jean Daussan, Metz / Moselle (France),
has been named as the inventor

According to one embodiment of the invention, the float consists of a shell section with full walls. The immersion depth of this envelope section is dimensioned so that the expansion the impurities, which on the one hand from the pouring stream, on the other hand from the destruction originate from the shell, is effectively prevented. These impurities remain collected in the Inside the float.

According to another embodiment, the float is designed so that it is when sliding up cannot rotate along the envelope in relation to the latter. In the submerged part of the wall of the float and / or in its bottom, if one is provided, are passage channels intended for the molten metal coming from the pouring stream. The passage channels are inclined in relation to the directions passing through the envelope axis in such a way that they cause the metal to rotate in the mold around the float.

This creates a centripetal accumulation due to the differences in specific gravity which causes contamination on the outer surface of the float. By that simple means one achieves that the impurities are collected away from the mold wall.

209 617/340

3 4

Further features are explained on the basis of the drawings. The shell G is explained with its upper part on the mold. attached. For example, it is by means of a kind Fig. 1 shows a longitudinal section along the line 1-1 clasp 1 is suspended from round bar which engages upwardly flared mold the projection c of the hood R of the Fig. 2 a, the sheath G crested and enveloping device according to the invention 5 traversed and at the opposite front; jumped a? is held with a bracket 2. Fig. 2 is a corresponding plan view; the lower end 3 of the sheath G (Fig. 1) ends in Ab-Fig. 3 and 4 show in longitudinal section the upper part stood h above the plate 4, which is placed on the bottom of the mold with the remaining shell mold and facilitates the attachment of the pre-device during or at the end of the casting device.

gangs; According to the invention, the sheath G is at its

Fig. 5 shows in longitudinal section along the line 5-5 lower part surrounded by a shell section T ,

6 shows a mold without a hood and one which represents a float. The swimmer T

Float, which the floating auxiliary piece lies tightly on the plate 4 before casting

surrounds the shell and at the end of the casting process 15 and can move without friction along the shell G

serves as a container for a vaporizable agent; move. The float Γ can be on the same

Fig. 6 is a corresponding plan view; the way as the shell G be made. The swimming

7 and 8 are mer T corresponding to FIGS. 3 and 4 can also consist of two parts.

Longitudinal sections; . The lower float part 5, which is immersed

Fig. 9 shows in a longitudinal section along the line 9-9 20 must be, this can consist of a refractory or

10, a device of the type of FIG. 1 also consist of such a material which by

up to 4, in which, however, the swimmer at his burn and / or slagging at his

submerged part has passage channels; Periphery is destructible. For example, this can

Fig. 10 is a horizontal section along the line part 5 made by rolling up cardboard,

10-10 of Figure 9; ² 5 whose turns at the beginning with a strong fire

Fig. 11 shows an embodiment according to FIG. 5, solid adhesives are glued, while the last

but with passage channels; Turns with a less refractory adhesive

Fig. 12 shows partly in view, partly in section, are medium glued, so that a superficial

according to the line 12-12 of FIG. 13, a variant is made possible in the case of combustion.

which of the floats has a bottom with a diameter of 30 The upper float part 6 can consist of the same

has access channels; Material like part 5 consist. But he can also, there

Fig. 13 is a horizontal section along the line he does not immerse in the molten pool, from one

13-13 of Figure 12; Material exist, which when reaching the

FIG. 14 shows a detail of an axial vertical point T ¹ (FIG. 4) at the upper end of the hood R

cut a mold with another execution 35 can easily be destroyed and then the task

shape of the float, which, like the last one, is an isolating agent and / or a heat-emitting one

named embodiments a rotational movement of the substance takes over. This is explained in more detail below

Melt causes; executed.

15 shows in vertical section the upper part of the The device works as follows: As soon as the mold with the view of the enveloping device at 4 ° the pouring jet / hits the plate 4, it spreads the end of the pouring process; gets out and rises vertically on the float T and FIG. 16 is the top corresponding to FIG. 15 - the cover G up the distance ef (FIG. 1). Since he sees; The interior of the shell G is very small, the level Fig. 17 shows in vertical section the lower part of the f-fim the interior of the shell quickly reached without the shell with float according to line 17-17 of FIG. 16. 45 time to the climbed metal Oxidation FIGS. 1 to 4 show the application of the invention, because the shell G and its small cover in a mold L, which are conical upward measurements, provide protection against oxidation, are expanded and are provided with a hood R. This experience shows that the metal is intended for a falling casting that is ultimately distributed outside the float, because calm steel, which penetrates from the ladle P in 50 it penetrates sufficiently quickly at the lower edge of a jet J , is poured. It rests with the float T and thereby generates a vertical force through the ground α on the base B. The ground α can, friction. This lifts the swim as is known per se, a middle part b made of refractory mer so far that the melt in the bottom of the material can possibly flow to its mold. The drainage takes place continuously with the same mold, also with increasing steps, and thanks to the float it is possible to pour. avoided that the spread of the pouring stream / the before casting, the shell G is reached in the mold L lateral inner wall g of the mold. Then used. The shell G can, as is known per se, the static buoyancy acts on the float T, by rolling up smooth or unilaterally corrugated since the melt will ultimately be produced the entire lower part of the cardboard. The consecutive 60 mold fills.

Windings are interconnected with a more The destructive effect of the pouring stream J is im

or less refractory glue glued. The lower part of the shell G is more or less unsurpassed

Envelope then becomes a square or visible. The plate 4 is never close to the

folded polygonal cross-section. For a lighter mold bottom, causing liquid metal under the Folding one chooses a 65 plate for the number of sides.

even number. The shell can also be made from each other as soon as the melt in the mold has reached the NN level

Material that burns or melts produced (Fig. 1) reaches an equilibrium

be. between the melt within the

direction GT and that which surrounds the wrapping device. This equilibrium is found at every level reached in the course of casting.

As soon as equilibrium is reached, the float T rises swimmingly as the watering progresses, but always with the same immersion depth i (FIG. 3).

The shell G, on the other hand, is continuously destroyed as the melt pool rises, with more of it or less irregular bottom edge roughly follows the bath level.

Fig. 3 shows e.g. B. the device at the moment when the level WW is reached. The float T always has the constant immersion depth i, while the casing G is partially consumed and has an irregular edge section 7 in the vicinity of the level WW.

Fig. 4 shows the device at the end of the casting process. The melt has reached the WW level in the hood R. The float T strikes against the clasp 1, as a result of which it is pressed into the melt in spite of the static buoyancy. The destruction ends when the WW level is reached. There is only a small piece of the envelope G above WW.

In Fig. 3 and 4 with S ¹ and S ^2, the peripheral, already solidified part of the metal is shown.

It can be seen from the various figures that the casing G does not protect the pouring jet J against atmospheric oxidation just like the known casings of this type, which takes place under the condition that the bottom of the ladle P is kept at the distance / above the casing, so that the suction effect of the pouring jet J is at all times less than the pressure of the combustion gases which rise from the molten bath inside the shell or its remainder. The cover also serves as a guide for the swimmer, which has the most important task in the combined device according to the invention for the following reasons:

a) At the beginning (Fig. 1) there is the possibility of using a shell G with a standardized length at least for a group of molds of the same type, in which the distance from the plate 4 to the upper edge of the hood R can differ by centimeters . The float T is lowered from above, slides along the cover and, after a slight rebound, takes the prescribed plate on the plate 4.

b) At level NN , the float prevents the pouring stream from spreading to the inner surface g of the mold L. This is of great importance since the impurities brought by the pouring stream would be held at the foot of the ingot and largely on its surface without the device of the invention.

c) In the course of casting, such as. B. in the level Ni-N ¹ (Fig. 3) can be seen, the scattering of the pouring stream / brought impurities is prevented, since the propagation takes place exactly according to the lines m.

d) In the event that the periphery of the float in part 6 is combustible, the solidification of the The jet is delayed because the gases escaping under sufficient pressure create turbulence cause.

e) In the WW level, the ash resulting from the destruction of the shell takes on the role of an insulating powder and / or a heat source.

5 to 8 show a mold L ¹ open on both sides without a hood. The embodiment of the invention illustrated here relates specifically to the casting of a rising or foaming metal, e.g. B. a non-killed steel.

The shell G ¹ is similar to that of the first embodiment and is in the same way by means of a

ίο the projection η cross brace l ^a and one among the projection ο cross strap ^2a fixed to the mold ^L1. In contrast, the float T ^{1 is} connected to a second float F ¹ , which forms a cover. Its profile corresponds exactly to the inner surface of the mold for the upper position shown in FIG.

The float F ¹ consists of two parts. The inner part 8 consists of a system of vertical channels arranged between vertical walls and, as known per se, e.g. B. consist of cardboard. The outer part 9 consists of rolled cardboard glued with a fire-proof binding agent, and is arranged so that, together with the float part T ^{1, it forms} an annular trough into which a coolant can be introduced.

Before casting, the casing G ^{1 is} inserted as in the first example and the assembled float ¹ P-, F ¹ is dropped along the casing so that it rests on the mold support 10.

At level NN , the same takes place as in the case of FIG. 1, and a few seconds after the start of pouring, equilibrium has been established, as shown in level WW (FIG. 8). It should be noted that the float F ^{1 is} slightly immersed in the steel bath, since the static buoyancy of the float 7 ¹ alone is insufficient, and the float F ^{1 is also held} by static buoyancy. This has the advantage of greater stability and makes it possible to let the cooling of the surface at the outer edge of the float 7 ¹ begin, and indeed at the most favorable level according to the nature of the foaming steel and its main elements to be taken into account, the contents of carbon and Manganese.

A fundamental specialty of the swimmer? ¹ 4 are cut-outs 11 in the region of the arms of the clip l ^a, can climb whereby the float in the level T ¹ WN ² without being destroyed. So it can be done at any level up to WW

such a cooling, as known per se, can be carried out, for which purpose a coolant such as water E, as shown in FIG. 7 at level WW , is used.

As in FIGS. 3 and 4, S ¹ and S ² denote the metal zone which begins to solidify in contact with the mold, unless the casting starts earlier, in which case this zone is strongly against the cooling float F ¹ would tend.

The ash and slag resulting from the destruction of the shell G ¹ remains at 12 in the interior of the lower part of the float T ¹ (FIG. 7) and can act as a cleaning compound depending on the adhesive used for the manufacture of the shell, e.g. B. sodium silicate is known to be a cleaning agent for ^ unkilled steel, since the oxides and impurities rise to the center of the bath surface, while the centripetal solidification through

table cross-section so that it can move on the sleeve G in the guide. The lower part 19, on the other hand, preferably has a circular cross-section so as not to inhibit the rotational movement of the melt in the mold 5. The rotational movement is generated by the ^{metal flowing out of the channels 15 or the mouths 17 in the direction of the arrows / 2} , which practically uses the entire energy of the pouring jet / for the rotational movement of the metal

the water evaporation in E takes place faster.

Embodiments are then described in which the swimmer is in the
Metal located at least in the vicinity of the mold
The float is set in a rotary motion. This is under the effect of the density differences
of metal and impurities and as a result of the
Difference in the centrifugal force acting on the metal and the impurities, a centrifugal accumulation of the impurities around the mold is applied, as in the examples in FIGS. 9 and 11, the float is reached. a centripetal collection of the impurities

According to the exemplary embodiment in FIG. 9 and at 13.

10, the float T ^{2 has} a greater thickness at its lower part of the dipping part than at its 15 is correct for a mold. V- with one of a top. In the lower part are downward-pointing rectangles derived cross-sections. The inner wall of channels 11 arranged obliquely to the radial one, has parallel surface lines, so that there is no divergence either upwards through the axis XX of the shell or the float or downwards. The mold going directions run. The channels are z. B. is arranged in its upper part with a conventional block perpendicular to these radii. Through this 20 head lining M provided. The casting takes place from channels the metal flows into the pouring stream / after the pouring ladle P.

it has distributed inside the float T ² , the covering device consists of the covering G and at least partially in the direction of the arrows / ¹ , and this is an auxiliary piece F acting as a float, all the more so as the molten bath already cast is made of any, by melting or distribution for the pouring stream / is impenetrable. 25 burn destructible material, such as smooth or

The float X ² is supported by the cover G

stepping pouring from below is decreasing with its upper part by means of two rods or

Sheath G out. Since the float itself is not mounted in tubes of V 'steel to the mold. the

Kind of a hydraulic turnstile through which rods I ⁶ are attached to the projections of the mold

The metal beams exiting the channels 12 are fixed in 30 and pass through the 4 sleeves or

Rotation can get, the surrounding rings 20, which are attached to two opposite ends

Melt bath set in rotary motion. tical surfaces of the shell G are arranged.

Experiments by the inventor have shown that the float F consists of the iron

with 4 channels with a cross-section from 3 to refractory material commonly used in industry. He has

6 cm ² each for a pouring stream / a cross section 35 an upper part 21 with a prismatic outer surface 22,

of the order of 10 to 20 cm ² and one which the z. B. square cross-section of the

ferrostatic pressure of a metal of approximately the shell G is matched, since the upper part 21 in the

Sheath G is inserted and should slide in it. The lower part 23 has a z. B. cylindrical outer

Density7, corresponding to a height of fall of 2 to 3 meters, has a sufficient twisting effect

the accumulation of the impurities at 13 40 surface 24, which over the fillet 25 with the prism

(Fig. 9) to ensure. The impurities are collected in this way on the outer surface of the float T ² away from the mold wall.

table surface22 is connected. The float / ⁷ has a recess 26 descending from above, the profile of which starts at the bottom from the center O in the form of two obliquely opening

The same result is obtained with the diverging channels 27 and 27a (FIG. 14). The coin set floats T ³ , F ¹ of Fig. 11, fertilize 28 and 28a are in the cylindrical

Surface 24. Two cavities 29 are provided on the underside of the float, which end on the side surface of the lower part 23 and two at 90 °

which represents a further development of the float of FIG. The arranged in the float part T ¹ below the float part F ¹ channels 12 be

act as a centripetal collection of grooves that are 5 ° offset from one another.

cleaning at 13 under the float part F ¹ and around the float part I ³ .

In the embodiment of FIGS. 12 and 13, the float T ^{4 is} very resistant

Before casting, the casing device G, F is inserted into the mold L ² as shown in the drawing.

From the beginning of the pouring it will look after

Bottom 14 provided, the shape of which during the 55 down somewhat scattering pouring stream / into the channels entire casting process is retained. This bottom 27, 27a is directed up to their mouths 28, 28a. Of the

The lower part of the mold is filled by an inclined flow, which flows from the mouths of the floating

offers the pouring stream a much stronger resistance than the weld pool. The bottom 14 is of helically curved

mers in the directions / ³ (Fig. 16). Here-

Channels 15 traversed, which at 16 on the surface 60 is through from the beginning of the casting onwards

and open at 17 to the lower surface of the bottom. They follow an approximately tangential direction with respect to a circle drawn around the axis XX.

In the mold, the molten bath rotates considerably in the direction of arrow / ⁴ . As a result, the impurities on the periphery of the float are already at level NN (Fig. 14)

In addition, the bottom 14 has collected in its central part 65 30. The static buoyancy that occurs in the

a bulge 18 which facilitates the propagation of the beam /.
The Γ ⁴ float has a square

Grooves 29 of the float begins and thus prevents it from sticking to the mold base B , lifts the float, and with rising

the height NN of the metal bath, the lower part of the shell G is destroyed. This process is repeated continuously up to the maximum level WN ^{1 of} the melt (FIG. 15), where the shell G is destroyed approximately up to the level WN ¹ .

During the ascent of the float, the metal of the pouring jet J continues to flow through the mouths 28, 28a and maintains the vortex movement from the level NN to the final level WN ^{1 of} the casting (FIG. 15).

In the case of a mold with a block head lining M (Fig. 15), the hollow float F protruding from the shell facilitates the filling of the void, which is promoted by the accumulation of impurities and ashes, which accumulate from level NN to level WN ¹ - at 30 as well as by the rotary movement of the upper part of the bath along the cast, which delays solidification.

It can be seen from the figures that the swivel movement is well guaranteed by the float, as well as the efficient destruction of the casing near the level of the cast metal, since the casing is never subject to the direct, destructive effect of the pouring jet J.

The recovery of the swimmer can be considered if the gain he made at the lost head is not profitable. To the float from the attached steel too you only need to bring it to the melting temperature of the steel. This is without further possible because the swimmer is made of very refractory material in view of the temperatures to be endured Material must be.

Of course, the invention is not limited to the embodiments shown, which are only examples represent limited.

In the described embodiments, especially in those cases where the cast metal is in The swimmer cannot turn around the shell, since both are polygonal Have cross-section. However, circular cross-sections can also be used below the condition that an appropriate guidance of the float on the shell is guaranteed.

The grooves 29 shown in the last example on the lower surface of the float can be straight 'and run radially, but better curved, as shown by dash-dotted lines for a channel in FIG. 16 is. All grooves converge to the center of the lower surface, so that the ones below it to high viscosity or impurities lingering for other reasons towards the center of the weld pool be guided.

55

Claims (13)

PATENT CLAIMS: 1. Sheath for the pouring stream with falling chill casting, which surrounds the pouring stream at a certain distance, characterized in that the shell (G, G ¹ ) attached with its upper part to the chill mold or possibly to the pouring ladle fixed during casting in relation to the chill mold is provided with an at least partially incombustible auxiliary piece in the form of a float (T, ¹ P-, T ² , T ³ , F) , which is adapted to the shell and arranged on it with such play that it can be moved along the shell without inhibiting friction is. 2. Apparatus according to claim 1, characterized by a float in the form of a Shell section. 3. Apparatus according to claim 2, characterized in that the lower part (S) of the float is more refractory than the upper part (6). 4. Apparatus according to claim 3, characterized in that the lower part (5) of the The float is more fireproof on the inside than on the outside. 5. Device according to claims 1 to 4, characterized in that the shaped as a shell section float (T ¹ ) is connected to a float part (F ¹ ) which comprises the former and extends to the mold wall and is designed so that it As is known per se, at the end of the casting process a vaporizable means for controlled cooling, in particular for centripetal cooling of the cast block surface, can be accommodated. 6. Apparatus according to claim 5, characterized in that the float (F ¹ ), as known per se, has a system of small channels opening onto the large surfaces of the float, which during casting the extraction of the gases coming from the cast metal allow on the melt pool surface, which has come outside of the inner shell-shaped float part (T ¹ ) , whereby the melt is protected against atmospheric air and oxidation. 7. Device according to claims 1 to 6, characterized in that the float (T) or the envelope-shaped float part (T ¹ ) has a full wall and the impurities collect on its inner surface. 8. The device according to claim 1, characterized in that the along the sheath displaceable float (T ² , V>, T \ F) of the sheath (G) is guided so that it can not rotate relative to the sheath, and in the immersing wall part of the float and / or in its bottom, if one is provided, channels ( 12, 15, 27, 27a) for the passage of the metal coming from the pouring stream are arranged, the channels with respect to the directions passing through the envelope axis are inclined so that the metal surrounding the float is set in rotary or whirling motion in the mold and a centripetal collection of the impurities takes place on the float. 9. Device according to claims 1 to 8, characterized in that the float is on the outside of the shell is displaceable at its end. 10. Device according to claims 1 to 8, characterized in that the float on inner end of the sheath is slidable. 11. The device according to claim 10, characterized in that the sheath (G) has a prismatic shape and the float (F, Fig. 14) has a correspondingly shaped upper part (21), while its lower part (24) has a cylindrical outer surface (24) has on which of the swimmer 209 617/340 Curved channels (27, 27α) coming inside open out. 12. The apparatus according to claim 11, characterized in that on the lower surface of the Float (14 to 17) channel-like depressions (29) are provided which open on the cylindrical outer surface (24). 13. The apparatus of claim 12, characterized by a number of radial, however flat curved floor gutters (29). For this purpose 2 sheets of drawings