US3850704A - Scarfing - Google Patents

Scarfing Download PDF

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Publication number
US3850704A
US3850704A US00330756A US33075673A US3850704A US 3850704 A US3850704 A US 3850704A US 00330756 A US00330756 A US 00330756A US 33075673 A US33075673 A US 33075673A US 3850704 A US3850704 A US 3850704A
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United States
Prior art keywords
air
slag
torch
strip
mould
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Expired - Lifetime
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US00330756A
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English (en)
Inventor
J Taggart
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Hilti AG
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Hilti AG
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Publication date
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    • 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
    • B23K7/00—Cutting, scarfing, or desurfacing by applying flames
    • B23K7/06—Machines, apparatus, or equipment specially designed for scarfing or desurfacing

Definitions

  • This invention relates to scarfing.
  • a steel ingot When a steel ingot has been cast it can have a rather rough surface and usually has slag and the like on its surface.
  • a flaming or scarfing gun To melt the surface of the metal and impart thereto a better finish.
  • Scarfing or flaming of a metal surface has, heretofore, not given a very good surface. Although a scarfed surface can be acceptable on an ingot before rolling it is not very acceptable on the interior of an ingot mould.
  • the invention provides a method of The air nozzle can be separate from theflaming gun or can be attached thereto.
  • the flame gun is moved, for example, by a first operative, along a series of adjacent parallel strips of the surface of the mould whilst the air or oxygen jet is directed, for example by a second operative, at the flame and area of the surface being melted by the flame gun, to move, from the surface of the molten metal created by the heat of the flame, any slag or impurities and transfer them to one side of the strip.
  • the slag and impurities are moved onto a surface which is either clean metal or has already been scarfed. This ensures that the area on the other side of the strip is not contaminated with slag or impurities and so can be easily scarfed later.
  • FIG. 1 is a fragmentary cross-section through an ingot mould showing a lower area of one face thereof;
  • FIG. 2 is a cross-section taken on the line II-II of FIG. 1;
  • FIG. 3 is a cross-section taken on the line III-III of FIG. 1;
  • FIG. 4 is a view similar to that of FIG. 1 but illustrating scarfing taking place
  • FIG. 5 is a view similar to that of FIG. 1 but after scarfing has been effected and after some slag and the like has been removed from the scarfed surface;
  • FIG. 6 is a cross-section taken on the lineVL-VI of FIG. 5;
  • FIG. 7 is a cross-section taken on the line VII-VII of FIG. 5.
  • a preferred embodiment of method conforming to the invention is concerned with ingot moulds.
  • Ingot moulds are usually of hollow frusto-pyramidal form having walls about ID to 14 inches thick and about 8 feet high and about 5 feet wide at their bases. They are usually made of haematite iron to resist the effects of molten steel thereon during pouring. After several ingots have been cast in a mould the inside walls thereof tend to become eroded and pitted. This damage can be extremely serious because if the walls become very damaged it may become impossible to remove a cast ingot therefrom because the steel of the ingot fills cavities eroded into the walls of the mould and forms a key.
  • FIG. 1 illustrates a lower area of an inside surface 10 ofa wall 11 of an ingot mould 12.
  • a pitted and scarred area 13 is indicated by dot-dash cross-hatching. It will be appreciated that all four walls of the mould 12 will be so affected and comparable pitted and scarred areas are visible at 14 and 15 in FIGS. 2 and 3.
  • the pitting is usually deepest at a position spaced away from the lower edge 16 of the mould 12, that is at that position which receives most splashed material during initial pouring of molten steel.
  • the steel hits a bottom plate (not shown), on which the mould 12 stands, and splashes back to hit the walls of the mould 12. Higher up the mould 12 the metal already in the mould 12 reduces splashing and so the upper parts of the mould walls remain comparatively clean.
  • Scarfmg is effected by a first operative lighting a flame gun or torch 17 shown only schematically in FIG.
  • Controls 20 and 21 are valves which control the propane and oxygen supply and control 22 serves to by-pass the control 21 for a purpose to be later described.
  • a second operative holds an air tube 25 which is shown only schematically in FIG. 4 and which comprises a nozzle 26 and a body 27 having a control valve 28 and being connected to a flexible air supply pipe.
  • the first operative operates control 22
  • the second operative opens valve 28 and allows a blast of air at 120 pounds per square inch impinge upon the area of metal heated by the flame. This blast of air is directed at an angle to the direction of the gun l7 and the accumulation of slag, impurities and iron oxides is moved onto the clean metal adjacent the flame on the left hand side thereof, This leaves no slag on the unscarfed area of the surface and allows the first operative to move the flame along the surface generally parallel to an adjacent side wall.
  • the second operative moves the air tube also, adjusting the direction, and quantity, of the air supplied to effectively remove the slag, etc. By this movement a strip 29 of scarfed surface is created with a line of slag 30 on the left hand side thereof.
  • FIG. 7 As can be best seen from FIG. 6 the junction between the strips are in the form of ridges 38 which do not affect removal of an ingot from the mould. If desired, however, they can be reduced or removed by scarfing therealong by the method described above.
  • FIG. 7, along with FIG. 5, also show a further step which may be necessary after the above described scarfing in strips.
  • the portion of the face 10 adjacent the lower edge 16 is usually not deeply pitted or eroded and, further, it is not always possible to commence scarfing the strips right at the edge 16 because of the danger of the flame bouncing back towards the operatives. This may result in a lip 35 (FIG. 7) being left along the lower edge.
  • This can be removed by scarfing a further strip 36, shown in dotted lines in FIG. 5, to remove the lip 35 and leave a surface as indicated by the dotted line 37 in FIG. 7.
  • the method described is, of course, effected on all four side walls of the mould.
  • the surface obtained by the method of the invention is highly acceptable and greatly enhances the life of an ingot mould.
  • the surface can, if the removal of slag is thoroughly effected, be shiny metal.
  • the invention is not limited to the precise details of the foregoing embodiment and variations can be made thereto.
  • oxygen can be supplied, via the air tube" instead of compressed air, although this is less effective.
  • a fairly good scarfing is still obtained, however.
  • the method of the invention is not limited to scarfing of ingot moulds and can be applied to any metal surface, for example steel ingots can be scarfed before rolling. This is an extremely important application because any slag or impurities on an ingot which is to be rolled tend to become rolled into the metal and so become weak areas in the final product.
  • the flame nozzle need not be of the propane/oxygen type and any practicable fuel gas can be used. Many other variations are, of course, possible.
  • a method of scarfing the inner wall surface of haematite iron ingot moulds using a flame torch characterized in that a jet of air or oxygen is directed towards that area of the inner wall surface of the mould being scarfed to remove any slag and impurities from the surface and to move such slag and impurities from the path of the flame torch and wherein a first strip of the .surface is scarfed, the slag and impurities being moved,
  • a method as claimed in claim 1, wherein the flame torch has three controls comprising, a valve for controlling the supply of compressed air or oxygen, a valve for controlling the supply of gas, and a by-pass control actuable to admit the full air or oxygen pressure to a nozzle of the torch, and inclusive of the following steps subsequent to the lighting of the torch; heating the inner wall surface of the mould by the flame until it starts to melt; operating the by-pass control to allow the full air or oxygen pressure to be supplied to the nozzle to commence burning of the inner wall surface; and switching on the jet of air or oxygen to remove the slag and/or impurities floating on the melted metal.
  • the air tube utilizes air supplied at over 100 pounds per square inch, preferably 120 pounds per square inch, through a tube at least 10 mm in diameter.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Arc Welding In General (AREA)
  • Gas Burners (AREA)
  • Manufacture And Refinement Of Metals (AREA)
US00330756A 1972-02-15 1973-02-08 Scarfing Expired - Lifetime US3850704A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB692072A GB1409262A (en) 1972-02-15 1972-02-15 Scarfing

Publications (1)

Publication Number Publication Date
US3850704A true US3850704A (en) 1974-11-26

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ID=9823273

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Application Number Title Priority Date Filing Date
US00330756A Expired - Lifetime US3850704A (en) 1972-02-15 1973-02-08 Scarfing

Country Status (9)

Country Link
US (1) US3850704A (OSRAM)
JP (1) JPS4889860A (OSRAM)
AU (1) AU471735B2 (OSRAM)
BE (1) BE795404A (OSRAM)
CA (1) CA985136A (OSRAM)
DE (1) DE2307319C3 (OSRAM)
ES (1) ES411662A1 (OSRAM)
FR (1) FR2172269B1 (OSRAM)
GB (1) GB1409262A (OSRAM)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4115153A (en) * 1976-07-19 1978-09-19 Centro-Maskin Goteborg Ab Method at gas planing
ES2103677A1 (es) * 1995-02-13 1997-09-16 Asturiana De Zinc Sa Instalacion para la eliminacion de impurezas en la colada de metales.

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3204997A1 (de) * 1982-02-12 1983-08-25 Robert Bosch Gmbh, 7000 Stuttgart Vorrichtung zur behandlung von werkstuecken in einer brennkammer
ES2144341B1 (es) * 1997-03-26 2001-01-01 Irgamex S L Procedimiento para efectuar el cierre de los fondos en recipientes que parten de piezas tubulares.

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2260322A (en) * 1939-04-22 1941-10-28 Oxweld Acetylene Co Deseaming and desurfacing apparatus and process
US2363089A (en) * 1942-08-21 1944-11-21 Linde Air Prod Co Welding process and apparatus
US3647570A (en) * 1969-06-25 1972-03-07 Union Carbide Corp Oxygen trap scarfing method and apparatus
US3752460A (en) * 1969-06-25 1973-08-14 Union Carbide Corp Oxygen trap scarfing apparatus

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1937089C3 (de) * 1969-07-22 1978-06-22 Tent S.A., Luxemburg Verfahren zum Flammen von Gegenständen aus Gußeisen mit Kugelgraphit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2260322A (en) * 1939-04-22 1941-10-28 Oxweld Acetylene Co Deseaming and desurfacing apparatus and process
US2363089A (en) * 1942-08-21 1944-11-21 Linde Air Prod Co Welding process and apparatus
US3647570A (en) * 1969-06-25 1972-03-07 Union Carbide Corp Oxygen trap scarfing method and apparatus
US3752460A (en) * 1969-06-25 1973-08-14 Union Carbide Corp Oxygen trap scarfing apparatus

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4115153A (en) * 1976-07-19 1978-09-19 Centro-Maskin Goteborg Ab Method at gas planing
ES2103677A1 (es) * 1995-02-13 1997-09-16 Asturiana De Zinc Sa Instalacion para la eliminacion de impurezas en la colada de metales.

Also Published As

Publication number Publication date
GB1409262A (en) 1975-10-08
DE2307319B2 (de) 1981-02-05
FR2172269A1 (OSRAM) 1973-09-28
AU471735B2 (en) 1976-04-29
BE795404A (fr) 1973-05-29
CA985136A (en) 1976-03-09
JPS4889860A (OSRAM) 1973-11-24
FR2172269B1 (OSRAM) 1976-11-05
DE2307319C3 (de) 1981-12-17
DE2307319A1 (de) 1973-08-30
AU5202073A (en) 1974-08-15
ES411662A1 (es) 1976-01-01

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