DE2355249A1 - BLOCK CASTING FORM, IN PARTICULAR FOR BLOCK CASTING FOR ELECTRIC SLASK - Google Patents

Description

BRITISH STEEL CORPORATION, a company by the regulations of the "Iron & Steel Act 1967", 33 »Grosvenor Place, London, S..W.-1., Great Britain

Block casting mold, especially for block casting at

Electro slag fine o

The invention relates to an ingot mold, in particular one Block casting mold, which can be used in block casting for electro-slag refining is.

In electroslag refining, a conductive slag becomes in a Mold in the molten state and at a temperature kept above the melting point of the metal to be fined. Unrepentant. Metal is inserted into the mold and refined, while it passes in the form of drops through a bath made up of the molten slag, with the fine drops settling to form a molten bath below the Collect slag bath »The walls of the mold and the Base plate of the casting mold are by circulating a coolant, usually ¥ water, chilled and becomes a solidified block below the molten metal pool built up. The metal to be fine can be put into the mold in Form of a consumable electrode can be introduced and the slag is generated by conducting an electric current from it

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the electrode to the base plate of the mold is kept in the molten state.

The known cast iron molds for use in electroslag refining have a one-piece construction. Such molds consist of an upper portion for receiving the from molten slag existing bath and a lower section of smaller cross-section, lh which one from the refined Metal existing block is molded. To keep the molded block within the lower mold section while As the block builds up during operation of the process, it has previously been necessary to either use the mold lift with respect to the molded block or withdraw the block downward from the mold. It turned out that this relative movement between the block and the mold leads to defects in the surface of the molded block. the Block mold according to the invention avoids these disadvantages.

In the case of an open-ended ingot mold, in particular for ingot casting in the case of electroslag, this is fine that consists of an upper section for receiving a quantity of molten, electrically conductive slag and a lower section of smaller cross-section as the upper portion in which a block of fine metal is formed, achieved by the The mold consists of a number of stacked, open-ended block castings, each of which has at least two in has moving parts in the horizontal plane, which portions of the side walls in spaced-apart positions of the upper mold section and in adjacent positions with their inner circumference section of the inner circumference of the lower mold section.

Further advantageous details and developments of the

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invention are characterized in the subclaims and result from the following description in which the invention is based on embodiments illustrated by way of example in the drawings is explained in more detail «In the drawings shows:

Figure 1 is a side sectional view of an apparatus for electroslag refining, which the invention Block mold contains;

FIG. 2 shows a plan view of the block casting mold according to FIG. 1 from above;

Figure 3 is a plan view of a further embodiment of the Block mold according to the invention;

FIG. 4 shows a perspective view of a number of cast molded parts arranged one above the other. who share a common Coolant distributors are connected;

Figures 5 and 6 are perspective and plan views, respectively a block mold according to the present invention, which is designed for the production of two blocks at the same time;

Figure 7 is a plan view of a block mold for manufacture of three blocks at the same time!

Figure 8 is a plan view of a block mold for making four blocks at a time;

Figure 9 is a perspective sectional view of a block casting mold for the production of a block of variable cross-section;

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FIG. 9a is a perspective view of a block mold produced with the block mold illustrated in FIG Block;

Figure 10 is a perspective sectional view of a

Block mold for the production of a block in the form of a roller with stitches;

FIG. 10a is a perspective view of a means produced by the block casting mold illustrated in FIG Block;

Figure 11 is a side sectional view of a block mold, in which a roller-shaped block is produced;

FIG. 12 is a perspective sectional view of a block casting mold for producing a block in the form a crankshaft and

FIG. 12a is a perspective view on an enlarged scale of a means of the means illustrated in FIG Block mold made block.

The device illustrated in FIGS. 1 and 2 contains a block casting mold 1 formed in a composite construction an upper storage container section 2 and a lower, section of smaller cross-sectional area than the upper storage container section 2 for forming the block. The lower section 3 encloses a Gießformhählung 4. The block mold 1 consists from a number of plate-like mold parts 5 placed one on top of the other, each of which is about 2.5 cm high, for example, each mold part is divided into two equal water-cooled parts 5a, 5b, which are located between the spaced-apart La-

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gen in which they have parts of opposite side walls of the upper reservoir section 2 of the block mold and adjacent positions in which their inner circumference is a part the circumference of the mold cavity 4 forms, are movable. The mold parts 5 are between stationary, water-cooled side parts 6 slidable, which together with the mold parts form the upper reservoir section 2 of the mold 1, when the mold parts are at a distance from one another Positions are located. The mold parts 5 and the side parts 6 are preferably made of copper. As already mentioned above, the parts 5a, 5b form the mold parts 5 in their neighboring ones Positions together the inner circumference of the mold cavity for this purpose are the opposite vertical surfaces of the parts 5a, 5b shaped in such a way that 'they have the required' Shape of the block to be produced in the mold cavity 4 form. In the case of the block mold illustrated in FIG. 2, a block with a circular cross section is to be produced.

It is obvious that by appropriate shaping of the opposite vertical faces of the parts 5a, 5b blocks different cross-sections can be produced. In Figure 3, for example, the opposite surfaces of the parts 5a, 5b are shaped such that when these parts are in their adjacent positions are located, these, together Form a square. ·

The various mold parts 5s which the block mold 1 in Form composite construction, are clamped together and at least on At the beginning, the lower end of the block mold 1 is on a cooled one Base plate 7 arranged insulated from this, a self-consuming electrode 8, for example made of steel or cast iron, is inserted into an electrode holder 9

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clamps, which is movable with respect to a mast 10 in the vertical direction. As the fining progresses, a block 11 is built up on the base plate 7. If a block of greater height than the sum of the height sections of the associated mold parts 5 is to be produced, one or more mold parts 5 are temporarily removed from the lower end of the block mold section 3 forming the block and placed on top of that mold part 5 which form the upper storage container section 2. For this purpose, the block casting mold 1 is supported on hydraulic reciprocating pistons 12 which, after one or more casting mold parts 5 have been removed from the lower end of the block casting mold, are extended upwards in order to rest against the casting mold part which is now furthest down. In the example illustrated in Figure 1, the mold parts 5 are arranged in groups of five pieces. The electrical current is conducted to the electrode 8 by a transformer (not shown) which is connected to the power supply. The current return path is established through a terminal provided on the base plate 7.

In operation, electrical current is conducted from the electrode 8 to the base plate 7 in order to have an electrical resistance Bath of molten slag 13 held in the upper reservoir section 2 is formed to a temperature at or above the melting point of the consumable electrode 8 to heat. The lower end of the electrode 8 is submerged in the slag bath 13. Drops made of unfined metal leave the electrode 8 and are refined as they pass through the slag bath 12 and collect as a molten bath 14 below the slag bath. Preferably, the upper surface of the metal pool 14 is at or slightly held below the interface between the upper mold section 2 and the lower mold section 3.

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As the height of the block 11 increases, the parts 5a, 5b of the mold part 5, which forms the lowermost section of the reservoir section 2, are moved inwardly to positions in which their inner surfaces meet, around the uppermost mold part of the mold cavity 4 * Figure 1 shows how the parts 5a, 5b of such a mold part 5 are moved from their spaced layers into their adjacent layers _o The mirror of the metal melt pool 14 can be detected by a gamma ray source.

By a certain distance between the tip of the electrode 8 and the surface of the weld pool made of metal 14 maintained «, the electrode 8 is continuous or periodically, raised by the electrode holder 9 * changes this, certain distance can be determined by capturing the changes one or more process parameters can be determined.

While the block 11 solidifies, those mold parts 5 of the lower, the block-forming mold section 3, which are no longer required for cooling and molding the block, removed from the block-forming section 3 and placed on top of those mold parts that "the reservoir broached 2 form, to be used to subsequently re ,, \ -jexm. the fiiveau the slag bath 13 in the portion 2 increases and the height of the block 11 increases, when the parts removed-are _5, the reciprocating pistons are extended 12 upward. The parts 5 can be moved individually or in groups of, for example, five to ten »

When an electrode 8 having an inner diameter larger than the inner diameter of the mold cavity 4 is used, the height is each mold part 5 is smaller than the specified distance

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between the electrode tip and the surface of the molten bath 14 made of metal.

As illustrated in Figure 4, the parts of each are Mold part 5 via flexible lines 15 to a main supply 16 for coolant, such as water, connected. Between the main line 16 and the hoses 15 is a rotatable Manifold 17 switched, which a movement of mold sections from clearing to the top of the composite construction Executed block mold 1 allowed without the associated line connections 15 being confused. The lines 15 can carry the coolant to individual mold parts or, as illustrated, to a group of mold parts conduct.

Figures 5 and 6 show a block mold by means of which two blocks can be produced at the same time. As illustrated, each of the parts 5a, 5b contains two sector-shaped sections 18. These sections cooperate with fluting 19 in the inner surfaces of the side parts 16 in order to create the adjacent Positions of the parts 5a, 5b to form two mold cavities 4a, 4b. More than one consumable electrode can do are melted at the same time in the storage container section 2.

Figures 7 and 8 show block molds which are used for production serve from more than two blocks at the same time. The block mold illustrated in Figure 7 consists of mold parts 5, which are composed of three parts 5a, 5b, 5c and three side parts 6. The parts 5a, 5b, 5c are spaced apart positions in which they are together with the side panels 6 form the upper reservoir section 2, and closed positions in which their most inwardly located

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converging surfaces, the inner perimeters of the three To form mold cavity, are movable, which by the interaction of the vertical, semicircular grooves 20 in the inner surfaces of the side parts 6- to be defined.

The block mold illustrated in Figure 8 is similar to that shown in FIG executed in Figure 7 illustrated construction, with the exception, that four the mold cavities by the nadi inwardly directed bend of four parts 5a, 5b, 5c and 5d between four appropriately shaped side parts 6 are formed can. . . .

In the reservoir section 2 of the mold an additional supply may be of heat for the slag-provided to prevent the slag solidifies in the small channels which are present when the parts 5a, 5b, _R 5c and 5d of the in the figures 7 8 and 8, the illustrated block molds are in their spaced apart positions. This additional heat can be supplied by means of electrical current from non-self-consuming electrodes, for example made of graphite, which are immersed in the slag baths, which are formed in the storage tank compartments, when the block casting molds are in operation.

Blocks whose cross-section changes over their length can be produced by block casting molds according to the present invention. For this purpose, for example, a block 11, as illustrated in FIG. 9a, can be formed by means of the block casting mold illustrated in FIG. This block mold consists in the specified order of mold parts 5s which form a circle in their closed positions, of mold parts 5 that form a circle of larger diameter and of mold parts 5 _? the one square

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23552Λ9

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form.

As illustrated in FIG. 10, the inner surfaces 21 of the casting mold parts 5 can be designed to be inclined to the vertical in order, for example, to produce stitches 22 in a cylindrical block. Such a block is illustrated in FIG. 10a. The pins 23 of the roller-shaped block are produced in that mold parts with a central opening of small diameter are arranged below and above the mold parts with central openings of larger diameter, the latter mold parts forming the desired surface of the roller body 24.

As illustrated in Figure 11, to form the upper pivot of a roller-shaped block, the parts 5a, 5b of a Mold part with a central opening corresponding to the required pivot diameter over the intermediate surface of the two block mold sections 2 and 3 moved when the level of the metal melt pool 14 is below (for example, 1.25 cm below) the interface is located. Molten slag will consequently be below of the cast part forming the pivot. This slag solidifies and forms a heat-insulating crust 25 showing a shrinkage of the top surface of the roller body of the cylindrical block prevents what could otherwise be caused by excessive cooling.

In Figure 12, a block mold for molding a block in the form of a crankshaft is illustrated. Such a block is shown in Figure 12a. The block mold consists of lower and upper mold parts, which mold cavities for molding Form lower and upper pivot pins 26, which are separated from one another by their own stationary larger mold part 27

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which forms the intermediate strut 28 of the crankshaft. In this embodiment, molten metal solidifies a consumable electrode initially in the lower mold cavity to form the lower pivot. The metal can then be fixed in the intermediate Mold part 27 enter and solidify in this section to to form the strut 28 of the Ebck. More than a self-consuming one Electrode can be melted off at this stage of the process. Alternatively, you can use a mottled or non-self-consuming Electrodes are used to remove the additional heating in the enlarged portion of the mold cavity to deliver. After the strut has been formed, the upper mold parts are moved to their closed positions to define the mold cavity for the upper pivot of the block to build. More than one strut can be formed by adding more Moldings are provided for forming struts and trunnions. The mold parts for shaping the struts can be offset at an angle to each other.

The overhead surface of each of the previously described mold parts can be concave in the direction of the central opening so that when they are on top of the forming the block Section 3 are arranged to support molten metal to flow in the direction of the mold cavity 4.

The invention achieves the advantage over known block molds with a storage container section and a section of different cross-sections forming the block, that there is no relative movement between the block mold and the block, so that a good surface quality of the Blockes. Is guaranteed.

All of those mentioned in the description and in the drawings recognizable technical details are important for the invention «

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Claims (7)

PATENT CLAIMS 1. Open-ended ingot mold, especially for ingot casting during Electroslag fine, with a top portion for receiving a quantity of molten electrically conductive slag and one lower section of smaller cross-section than the upper section in which a block of fine metal is formed is characterized in that the block mold consists of a number of open-ended mold parts (5) arranged one above the other consists, each of at least two in the horizontal plane between positions located at a distance, in which they sections the side walls of the upper mold section (2) / and adjacent positions in which their inner surfaces Parts of the inner circumference of the lower mold section (3) form, movable parts (5a, 5b, 5c, 5d) exist. 2. Block mold according to claim 1, characterized in that the mold parts (5) 'between stationary side parts (6) are slidable, which together with the mold parts (5) in their spaced positions, the side walls of the upper mold section (2). 3. Block mold according to claim 1 or 2, characterized in that each mold part (5) inner channels for guiding Contains coolant. 4. Block mold according to one or more of the preceding claims, characterized in that the mold parts (5) are supported at the bottom by an extendable piston (12), such that mold parts (5) from the underside of the composite construction executed block mold (1) can be removed, while the rest of the mold parts (5) with respect to the molded block (11) are held in place. 409820 / 08S0 5. Block mold according to one or more of the preceding claims, characterized in that the inner surfaces of the mold parts (5) are shaped so that they - in their neighboring Positions form a mold cavity (4, 4a, 4b, 4c, 22, 23, 24, 26) with a circular cross-section. 6. Block mold according to one or more of claims 1 to 4, characterized in that the inner surfaces of the mold parts (5) are shaped in such a way that they are in their neighboring Positions form a mold cavity (4) with a polygonal cross-section. 7. Block mold according to one or more of claims 1 to 4, characterized in that the inner surfaces of the mold parts (5) are shaped such that they form a mold cavity (4, 21, 28) in their adjacent positions, the Cross-section changes over the length. 4098 20/08 5 0 Blank page