CA1263151A - Ceramic shoes for electroslag welding - Google Patents
Ceramic shoes for electroslag weldingInfo
- Publication number
- CA1263151A CA1263151A CA000527544A CA527544A CA1263151A CA 1263151 A CA1263151 A CA 1263151A CA 000527544 A CA000527544 A CA 000527544A CA 527544 A CA527544 A CA 527544A CA 1263151 A CA1263151 A CA 1263151A
- Authority
- CA
- Canada
- Prior art keywords
- workpieces
- shoe
- shoes
- ceramic
- cast
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K25/00—Slag welding, i.e. using a heated layer or mass of powder, slag, or the like in contact with the material to be joined
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Ceramic Products (AREA)
Abstract
CERAMIC SHOES FOR ELECTROSLAG WELDING
ABSTRACT OF THE DISCLOSURE
There is disclosed an electroslag welding process and unitary ceramic refractory damming shoes for this process. The damming shoes may be cast or molded into various required shapes to accommodate complex joint profiles at relatively cheap costs.
ABSTRACT OF THE DISCLOSURE
There is disclosed an electroslag welding process and unitary ceramic refractory damming shoes for this process. The damming shoes may be cast or molded into various required shapes to accommodate complex joint profiles at relatively cheap costs.
Description
3~5~
CERAMIC SHOES FOR ELECTROSLAG WELDING
FIELD OF THE INVENTION
The present invention relates to the use of damming shoes in electroslag welding. More specifically, it relates to the use of a unitary ceramic damming shoe that may be readily cast or moulded into a desired shape.
BACKGROUND OF THE INVENTION
_ The current process of electroslag welding involves positioning generally two but possibly three or even four workpieces so that a space or gap is provided between these workpieces~ Damming shoes extend across the workpieces to vertically form a gap and provide a closure, which is effectively the weld joint. This closure is extended below and above the workpieces a distance of approximately 3_4 n in order to provide a satisfactory weld at both ends, these extensions are removed after welding. A consumable electrode is placed in the gap to provide a weld pool that rises in the closure. As the weld pool cools it solidifies welding the workpieces. The damming shoes are removed for further use.
At present, copper damming shoes are the preferred type of damming shoe used in electroslag welding. The shoes usually comprise a composite construction of a copper surface that faces the weld ~L21~ii3:~L5~
CERAMIC SHOES FOR ELECTROSLAG WELDING
FIELD OF THE INVENTION
The present invention relates to the use of damming shoes in electroslag welding. More specifically, it relates to the use of a unitary ceramic damming shoe that may be readily cast or moulded into a desired shape.
BACKGROUND OF THE INVENTION
_ The current process of electroslag welding involves positioning generally two but possibly three or even four workpieces so that a space or gap is provided between these workpieces~ Damming shoes extend across the workpieces to vertically form a gap and provide a closure, which is effectively the weld joint. This closure is extended below and above the workpieces a distance of approximately 3_4 n in order to provide a satisfactory weld at both ends, these extensions are removed after welding. A consumable electrode is placed in the gap to provide a weld pool that rises in the closure. As the weld pool cools it solidifies welding the workpieces. The damming shoes are removed for further use.
At present, copper damming shoes are the preferred type of damming shoe used in electroslag welding. The shoes usually comprise a composite construction of a copper surface that faces the weld ~L21~ii3:~L5~
- 2 -pool and a steel or copper backing. The steel or copper backing includes internal passages through which water is circulated to transfer heat from the shoe and speed up the cooling of the metal and slay in the weld pool. The disadvantage with copper shoes is that the shoes are rather expensive to manufacture, particularly for shapes other than flat welds where the copper facing part of the shoes must be formed by metal moulding techniques such as machining or other expensive metal shaping operations whlch also limits these shapes to relatively simple ones. Additionally, since the shoe is relatively expensive, effort is made to use it repeatedly and thus it requires maintenance.
~nother type of damming shoe has been disclosed in canadian Patent 787,550 issued June ll, 1968 to Shrubshall et al. The shoe is composed of moulded metal, such as copper, and is provided with vertical recesses or grooves that face toward the space between the workpieces. In these grooves a pre-cast ceramic part is positioned. The ceramic may be shaped to the the specific contour required. The ceramic parts in fact merely constitute a thick coating on the metal mould. This shoe is relatively expensive to construct in that it requires a moulded copper metal and the insertion or coating of a ceramic refractory part onto the metal.
There is a need for a damming shoe that is less expensive than the above described shoes and which can be readily manufactured into either simple or complex shapes. While electroslag welding is a rapid and cost effective method of joining thick sections, its a~ceptance in the industry has been delayed due to the inability to provide realtively cheap and complexly shaped structures which can be used several times or on a customized basis. Due to this, the use of electroslag welding has declined.
. . , `: :
`:
~2~i3~5~
GOK .1~2-223 SI~MMARY OF THE INVENTION
It is an object of the present invention to provide a damming shoe for use in electroslag welding that requires no maintanence, is relatively inexpensive to manufacture and can be formed in relatively complex shapes.
In accordance with one aspect of the present invention there is provided a method of electroslag welding at least two workpieces having predetermined side surface contours. The method includes the steps of:
orienting the workpieces in spaced apart and aligned relation;
positioning a unitary ceramic refractory shoe adjacent each one of corresponding sides of the workpieces to close the space between the workpieces, the shoe being cast or moulded to provide a shape commensurate with the predetermined side surface contours of the workpieces so as to provide a weld pool facing surface that conforms to the side contours of the workpieces;
providing a welding assembly and creating a weld pool which rises from the bottom of the closed space vertically, welding the workpieces and conforming to the shape of the ceramic damming shoes;
allowing the weld pool to cool and solidify into a weldment; and, removing the shoes from the weldment.
It should be understood that the welding assembly may comprise a consumable nozzle through which a welding wire or electrode passes for creating the weld pool.
In accordance with another aspect of the present invention there is provided a shoe Eor use in electroslag welding as a dam between two spaced apart workpieces. The shoe consists of a unitary refractory ::` . . :
. .
~ '~G3~
G~K 102-223 _ ~ ~
ceramic shoe Eormed by one of casting or moulding either ~eparate Erom the workpiece or directly on the workpieces where it will stay till welding is complete. The shoe is cast or moulded in a predetermined shape with an inside surEace contour corresponding to that of corresponding side surfaces of the workpieces.
The above described welding or damming shoe has the advantage that it is considerably cheaper to manufacture than composite shoes using metal parts.
Further, by moulding or casting the shoe, the shoe can take on a variety of shapes and contours so that the shoe can be used in customized welds. As a result, the shoe can be used on a one time basis and can be consumed by the process so to speak. Such a shoe requires no labour intensive maintainence.
It is envisaged that the shoe may be cast or moulded from a ceramic material selected from the group comprising graphite, alumina~ silica, zirconia, magnesia or combinations thereo~. Further, the shoe may have a rear face that is substantially flat and a front face adapted to face the weld pool which front face has a predetermined contour corresponding to the contour o~ the workpieces whereby the thickness of the unitary shoe varies.
BRIEF DESCRIPTION OF THE DRAWINGS
_ For a better understanding of the nature and objects of the present invention reference may be had by way of example to the accompanying diagrammatic drawings in which:
Figure 1 is a schematic drawing showing the use o~ the refractory ceramic shoes of the present in~ention at one stage of the electroslag welding process.
Figure 2 is a cross-section drawing of the arrangement in Eigure :L taken at lines II~
.
' ., ~:: ., ~ .' ' :-, ~3~
DETAILED DESCRIPTION OF THE PRESEN~ INVENTION
.
Referring to Figure 1, there is shown two workpieces 10 and 12 which are to be joined and are arranged in vertical orientation with the two edges to be jolned adjacent. Typically, a 1 ~ /47 gap 14 separates workpieces 10 and 12. It should be understood that lt is not necessary for the workpieces to be even thickness from top to bottom~
Refractory damming shoes 16 and 18 are then positioned across the two open faces to create a vertical enclosed gap or space which will constitute the weld joint. The refractory shoes 16 and 18 can also form the closure below the joint of the two pieces generally leaving an extended gap of 3_4 n below the workpieces Isee Figure 2). The refractory shoes 16 and 18 can be shaped by casting or moulding separate from the workpieces or plastic refractory material can be moulded directly to the workpieces, dried and set ready for welding.
consumable guide tubes 20 are arranged in the vertical gap 14 as shown in Figure 2. If the gap 14 varies in thickness from bottom to top, guide tubes of varying lengths can be employed. Some guide tubes may be located higher in the joint to commence welding as the liquid weld metal rises in the joint to their higher level. Wires 22, which constitute the electrode, continually pass through consumable guide tubes 20 during welding.
The weld is commenced at the bottom of the gap 14 and rises vertically. Other guide tubes and corresponding wire electrodes become operative as the liquid weld metal rises and contacts them. This is the preferrably the case for welds of uneven, complex geometry. When the weld fills the weld joint and the extension above the workpieces (not shown in Fig. 1 .. ' - '' , .
.
~3~
for clarit~), the weld solidifies and cools. After solidification, the ceramic, damming shoes are removed.
The present invention is concerned with the use o~ damming shoes 16 and 18. These shoes are composed of a unitary ceramic refractory material which can be cast separately or moulded onto the workpieces and thereby take the shape of the workpiece. The material of the shoe comprises graphite, alumina, silica, zirconia, magnesia or combinations thereof.
Tests have been performed using a zirconia based refractory Plicast C-2582B and an alumina based refractory Plicast 40 having respective service limit temperatures of 1480C and 1760C. Both these refractories provided satisfactory weldsO The welds made using the refractory shoes were in fact finer grained than similar welds made using copper water cooled shoes. Coarse grains with attendent brittleness problems are a feature of electroslag welds and have brought the process into some discredit. Thus, it appears that the use oE ceramic shoes may improve the properties of electroslag welds resulting in greater use of electroslag welding. The main advantage of electroslag welding is its ver~ high deposition rate and quick welding times for thick members and its greater use on such members would lead to improved economics on welding costs.
. ~ , . .
.
:
.
~nother type of damming shoe has been disclosed in canadian Patent 787,550 issued June ll, 1968 to Shrubshall et al. The shoe is composed of moulded metal, such as copper, and is provided with vertical recesses or grooves that face toward the space between the workpieces. In these grooves a pre-cast ceramic part is positioned. The ceramic may be shaped to the the specific contour required. The ceramic parts in fact merely constitute a thick coating on the metal mould. This shoe is relatively expensive to construct in that it requires a moulded copper metal and the insertion or coating of a ceramic refractory part onto the metal.
There is a need for a damming shoe that is less expensive than the above described shoes and which can be readily manufactured into either simple or complex shapes. While electroslag welding is a rapid and cost effective method of joining thick sections, its a~ceptance in the industry has been delayed due to the inability to provide realtively cheap and complexly shaped structures which can be used several times or on a customized basis. Due to this, the use of electroslag welding has declined.
. . , `: :
`:
~2~i3~5~
GOK .1~2-223 SI~MMARY OF THE INVENTION
It is an object of the present invention to provide a damming shoe for use in electroslag welding that requires no maintanence, is relatively inexpensive to manufacture and can be formed in relatively complex shapes.
In accordance with one aspect of the present invention there is provided a method of electroslag welding at least two workpieces having predetermined side surface contours. The method includes the steps of:
orienting the workpieces in spaced apart and aligned relation;
positioning a unitary ceramic refractory shoe adjacent each one of corresponding sides of the workpieces to close the space between the workpieces, the shoe being cast or moulded to provide a shape commensurate with the predetermined side surface contours of the workpieces so as to provide a weld pool facing surface that conforms to the side contours of the workpieces;
providing a welding assembly and creating a weld pool which rises from the bottom of the closed space vertically, welding the workpieces and conforming to the shape of the ceramic damming shoes;
allowing the weld pool to cool and solidify into a weldment; and, removing the shoes from the weldment.
It should be understood that the welding assembly may comprise a consumable nozzle through which a welding wire or electrode passes for creating the weld pool.
In accordance with another aspect of the present invention there is provided a shoe Eor use in electroslag welding as a dam between two spaced apart workpieces. The shoe consists of a unitary refractory ::` . . :
. .
~ '~G3~
G~K 102-223 _ ~ ~
ceramic shoe Eormed by one of casting or moulding either ~eparate Erom the workpiece or directly on the workpieces where it will stay till welding is complete. The shoe is cast or moulded in a predetermined shape with an inside surEace contour corresponding to that of corresponding side surfaces of the workpieces.
The above described welding or damming shoe has the advantage that it is considerably cheaper to manufacture than composite shoes using metal parts.
Further, by moulding or casting the shoe, the shoe can take on a variety of shapes and contours so that the shoe can be used in customized welds. As a result, the shoe can be used on a one time basis and can be consumed by the process so to speak. Such a shoe requires no labour intensive maintainence.
It is envisaged that the shoe may be cast or moulded from a ceramic material selected from the group comprising graphite, alumina~ silica, zirconia, magnesia or combinations thereo~. Further, the shoe may have a rear face that is substantially flat and a front face adapted to face the weld pool which front face has a predetermined contour corresponding to the contour o~ the workpieces whereby the thickness of the unitary shoe varies.
BRIEF DESCRIPTION OF THE DRAWINGS
_ For a better understanding of the nature and objects of the present invention reference may be had by way of example to the accompanying diagrammatic drawings in which:
Figure 1 is a schematic drawing showing the use o~ the refractory ceramic shoes of the present in~ention at one stage of the electroslag welding process.
Figure 2 is a cross-section drawing of the arrangement in Eigure :L taken at lines II~
.
' ., ~:: ., ~ .' ' :-, ~3~
DETAILED DESCRIPTION OF THE PRESEN~ INVENTION
.
Referring to Figure 1, there is shown two workpieces 10 and 12 which are to be joined and are arranged in vertical orientation with the two edges to be jolned adjacent. Typically, a 1 ~ /47 gap 14 separates workpieces 10 and 12. It should be understood that lt is not necessary for the workpieces to be even thickness from top to bottom~
Refractory damming shoes 16 and 18 are then positioned across the two open faces to create a vertical enclosed gap or space which will constitute the weld joint. The refractory shoes 16 and 18 can also form the closure below the joint of the two pieces generally leaving an extended gap of 3_4 n below the workpieces Isee Figure 2). The refractory shoes 16 and 18 can be shaped by casting or moulding separate from the workpieces or plastic refractory material can be moulded directly to the workpieces, dried and set ready for welding.
consumable guide tubes 20 are arranged in the vertical gap 14 as shown in Figure 2. If the gap 14 varies in thickness from bottom to top, guide tubes of varying lengths can be employed. Some guide tubes may be located higher in the joint to commence welding as the liquid weld metal rises in the joint to their higher level. Wires 22, which constitute the electrode, continually pass through consumable guide tubes 20 during welding.
The weld is commenced at the bottom of the gap 14 and rises vertically. Other guide tubes and corresponding wire electrodes become operative as the liquid weld metal rises and contacts them. This is the preferrably the case for welds of uneven, complex geometry. When the weld fills the weld joint and the extension above the workpieces (not shown in Fig. 1 .. ' - '' , .
.
~3~
for clarit~), the weld solidifies and cools. After solidification, the ceramic, damming shoes are removed.
The present invention is concerned with the use o~ damming shoes 16 and 18. These shoes are composed of a unitary ceramic refractory material which can be cast separately or moulded onto the workpieces and thereby take the shape of the workpiece. The material of the shoe comprises graphite, alumina, silica, zirconia, magnesia or combinations thereof.
Tests have been performed using a zirconia based refractory Plicast C-2582B and an alumina based refractory Plicast 40 having respective service limit temperatures of 1480C and 1760C. Both these refractories provided satisfactory weldsO The welds made using the refractory shoes were in fact finer grained than similar welds made using copper water cooled shoes. Coarse grains with attendent brittleness problems are a feature of electroslag welds and have brought the process into some discredit. Thus, it appears that the use oE ceramic shoes may improve the properties of electroslag welds resulting in greater use of electroslag welding. The main advantage of electroslag welding is its ver~ high deposition rate and quick welding times for thick members and its greater use on such members would lead to improved economics on welding costs.
. ~ , . .
.
:
.
Claims (11)
1. A method of electroslag welding at least two workpieces each having predetermined side surface contours comprising:
orienting the workpieces in spaced apart and aligned relation;
positioning a unitary ceramic refractory shoe adjacent each one of corresponding sides of the workpieces to close the space between the workpieces, said shoe being cast or moulded to provide a shape commensurate with the predetermined side surface contours of the workpieces so as to provide a weld pool facing surface that conforms to the side contours of the workpieces;
providing a welding assembly and creating a weld pool which rises from the bottom of the closed space vertically, welding the workpieces and conforming to the shape of the ceramic damming shoes;
allowing the weld pool to cool and solidify into a weldment; and, removing the shoes from the weldment.
orienting the workpieces in spaced apart and aligned relation;
positioning a unitary ceramic refractory shoe adjacent each one of corresponding sides of the workpieces to close the space between the workpieces, said shoe being cast or moulded to provide a shape commensurate with the predetermined side surface contours of the workpieces so as to provide a weld pool facing surface that conforms to the side contours of the workpieces;
providing a welding assembly and creating a weld pool which rises from the bottom of the closed space vertically, welding the workpieces and conforming to the shape of the ceramic damming shoes;
allowing the weld pool to cool and solidify into a weldment; and, removing the shoes from the weldment.
2. The method of claim 1 wherein the shoe is cast from a ceramic material selected from the group comprising graphite, alumina, silica, zirconia, magnesia and combinations thereof.
3. The method of claim 1 wherein the shoe is moulded from a ceramic material selected from the group comprising graphite, aluminum, silicon, zirconium, magnesium and combinations thereof.
4. The method of claim 1 or 2 wherein the shoes are cast separately from the workpieces.
5. The method of claim 1 or 2 wherein the shoes are cast directly on the workpieces.
6. The method of claim 1 or 3 wherein the shoes are moulded separately from the workpieces.
7. The method of claim 1 or 3 wherein the shoes are moulded directly on the workpieces.
8. A shoe for use in electroslag welding as a dam between two spaced apart workpieces consisting of a unitary refractory ceramic shoe formed by one of casting and moulding in a predetermined shape with an inside surface contour corresponding to that of corresponding side surfaces of the workpieces.
9. The shoe of claim 8 wherein the shoe is cast from a ceramic material selected from the group comprising graphite, alumina, silica, zirconia, magnesia and combinations thereof.
10. The shoe of claim 8 wherein the shoe is moulded from a ceramic material selected from the group comprising graphite, alumina, silica, zirconia, magnesia and combinations thereof.
11. The shoe of claim 8 wherein the shoe has a rear face that is substantially flat and has a front face adapted to face the weld pool which has a predetermined contour corresponding to the contour of the workpieces whereby the thickness of the unitary shoe varies.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000527544A CA1263151A (en) | 1987-01-16 | 1987-01-16 | Ceramic shoes for electroslag welding |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000527544A CA1263151A (en) | 1987-01-16 | 1987-01-16 | Ceramic shoes for electroslag welding |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1263151A true CA1263151A (en) | 1989-11-21 |
Family
ID=4134777
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000527544A Expired CA1263151A (en) | 1987-01-16 | 1987-01-16 | Ceramic shoes for electroslag welding |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1263151A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6297472B1 (en) | 1998-04-10 | 2001-10-02 | Aromatic Integrated Systems, Inc. | Welding system and method |
-
1987
- 1987-01-16 CA CA000527544A patent/CA1263151A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6297472B1 (en) | 1998-04-10 | 2001-10-02 | Aromatic Integrated Systems, Inc. | Welding system and method |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6564856B1 (en) | Method of making precision castings using thixotropic materials | |
| US4493363A (en) | Method at continuous casting of steels and metal alloys with segregation tendency and apparatus for carrying out the method | |
| FI97108C (en) | Use of a curable copper alloy | |
| US3891821A (en) | Method for repairing iron molds used in steel making, casting plates in iron molds and other objects made of cast iron | |
| CA1263151A (en) | Ceramic shoes for electroslag welding | |
| US3721286A (en) | Method of obtaining metal hollow ingots by the elastroslag remelting | |
| JPH07155897A (en) | Mold structure and casting method | |
| US6116328A (en) | Fabrication of tile reinforced composite armor casting | |
| US4120695A (en) | Process of the electroslag remelting of consumable electrodes | |
| US1762598A (en) | Art of and mold for casting piston rings | |
| EP0326214A1 (en) | Method and apparatus for manufacturing a magnetic chuck | |
| JPS62252638A (en) | Production of molding tool | |
| RU2098222C1 (en) | Method for repair of mold of continuous casting machine and mold for its embodiment | |
| US929777A (en) | Process of producing coated metal objects. | |
| US3794101A (en) | Method of casting metals in metal mold | |
| KR100530103B1 (en) | Mold without Surface Crack in Thin Slab Continuous Caster | |
| RU2030955C1 (en) | Metal continuous pouring crystallizer | |
| SU1452654A1 (en) | Method of producing bimetallic billet | |
| JPS61111743A (en) | Production of clad steel ingot | |
| SU565534A1 (en) | Apparatus for electroslag casting of hollow ingots | |
| SU997961A1 (en) | Curvilinear mould to metal continuous casting units | |
| Sabath | EM Casting of Aluminum Alloys.(WAA Translation Available) | |
| SU1199419A1 (en) | Method of making shape-forming tools | |
| JPS61206545A (en) | Die for die casting | |
| Hrbacek | Technology and Economic Feasibility of EM Casting.(WAA Translation Available) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |