US2189753A - Billet conditioning method - Google Patents

Description

Feb. 13, 1940. BUCKNAM ET AL 2,189,753

BILLET CONDITIONING METHOD Filed April 24, 1957 2 Sheets-Sheet l INVENTORS JAMES H. BUCKNAM F3 BYALFRED MILLER [20 A TTORNEY Feb. 13, 1940. J. H. BUCKNAM ET AL BILLET CONDITIONING METHOD Filed April 24, 1937 2 Sheets-Sheet 2 mo R.

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INVENTORS JAMES H. BUCKNAM By ALFRED L1 MILLER ATTORNEY Patented Feb. 13 '1940 UNITED STATES BILLET CONDITIONING METHOD James H. Bucknam and Alfred J, Miller, Oranford, N. J., assignors to The Linde Air Products Company, a corporation of Ohio Application April 24, 1937, Serial No. 138,71

4 Claims.

This invention relates to the art of conditioning metal bodies, such as steel ingots and billets by means of an oxidizing stream; and more particularly to a novel method of quickly cutting off, or

5 cropping, the scrap ends of steel ingots or billets and other ferrous bodies and thermo-chemically removing surface layers of metal from such bodies.

A steel ingot is usually formed by pouring molwhich is formed of refractory material. As the metal cools, gas bubbles and impurities rise to the top of the ingot, forming what is known as a hot top within the refractory portion of the mould. This hot top is mostly porous metal that must be removed, and many surface defects in the sides of the ingot occur which also must be eliminated before the ingot is subjected to semi-finishing operations. Furthermore, semi-finished shapes that are formed from the ingot, such as billets, blooms, slabs, and the like, have irregular end portions, and their surfaces contain additional defects which must be eliminated. These irregular ends are cut off and the surfaces are desurfaced to improve them for subsequent rolling.

This surface metal-removing operation may be accomplished by suitable apparatus for progressively applying an oxidizing stream obliquely against and lengthwise of the surface while the latter is at an ignition temperature. Such apparatus usually includes a row of blowpipes, having nozzles adapted to deliver jets of heating and oxidizing gases, these several nozzles preferably being sufllciently close together to provide in effect a single wide high-temperature heating flame and an associated single relatively wide oxidizing stream of substantially the same width as the surface to be conditioned. The width, as well as the contour or vertical and horizontal camber of m shapes requiring surfacing vary, and therefore the surface-removing apparatus should be sumciently flexible to be capable of economically anduniformly performing the surfacing operation on metal bodies of different widths and form.

Heretofore, the hot top of a cast ingot was usually cropped by a hot-shearing operation forming a shear burr at the cropped end, making it diiilcult to start a desurfacing operation at all four end edges thereof. Furthermore, surface-removing operations have been started near one of the irregular ends of the semi-finished shapes and progressively advanced to the other end thereof, thus a portion of the surface-re moving operation was applied to a portion of the shape that was subsequently scrapped. Itis not ten steel into a vertical mould, the top portion of ished steel shape directly prior to the biginning only diflicult, but also wastes time and gas to begin a metal removing operation at an irregularly-formed end edge of a billet.

Inasmuch as ingots and billets weigh several tons, their handling during preparation for roll- 5 ing is an important factor of the cost of the finished product.

The principal objects of the invention are: to provide a method of conditioning a ferrous metal body having an irregularly formed waste end which comprises removing said waste end together with the removal of surface defects while employing'a minimum of handling operations; to provide an improved method of conditioning a ferrous metal body having an irregularly formed waste end which comprises first cutting off, or cropping, the irregular waste end to provide a square end edge, and then directly thereafter thermo-chemically desurfacing the so-prepared body by starting the desurfacing at the newly formed square edge of the body; and to provide an improved method of quickly thermo-chemically cutting off, or cropping, the irregular waste end of an ingot, billet, bloom, or other semi-finof a thermo-chemical surface-removing operation; and for thermo-chemically cutting off the other end of such shape directly after such surface-removing operation.

The above and other objects and the novel features of this invention will become apparent from the following description taken with the accompanying drawings, in which:

Fig. 1 is a plan view of a multiple unit blowpipe machine embodying the principles of this invention;

Fig. 2 is a broken elevation of the machine shown in Fig. 1; and

Fig. 3 is a section taken along line 3 -3 of Fig. 2. Broadly, th apparatus for carrying out the method accor g to the invention comprises means, such as an assembly of blowpipe units disposed side by side, to produce a wide and substantially continuous metal-removing stream of gaseous heating and oxidizing agents, supported in such position with respect to a billet surface from which a layer of metal is to be removed that the metal-removing stream will impinge obliquely against, and lengthwise of the surface across its entire width or a substantial portion thereof, together with a cutting-'torch'assembly adapted to deliver gaseous heating and oxidizing agents for cropping off the waste ends of such billet. The supporting means is common to both assemblies and is adapted to move them back and 55 forth lengthwise as well as transversely of the billet, and also to permit a limited longitudinal and perpendicular adjustment of both assemblies relatively to the billet surface.

The blowpipe assembly for desurfacing, the cutting-torch assembly for cropping the waste ends of the metal bodies, and the supporting means therefor, as shown, comprise a travelling crane structure C; a supporting abutment S depending therefrom; a linkage system L carried by the abutment S; a plurality of desurfacing blowpipe units disposed side by side and separately carried by the linkage system adjacent a ferrous metal body or billet P; and a cutting torch assembly T. Each desurfacing blowpipe unit comprises a blowpipe head H having a nozzle N thereon which delivers gaseous heating jets and oxidizing jets of relatively low velocity and large volume, and the several blowpipes and nozzles are sufficiently close together to provide a substantially continuous heating flame as wide as the surface and an associated oxidizing stream of the same width. The cutting torch assembly T is mounted adjacent the desurfacing blowpipe unit and delivers gaseous heating jets and an oxidizing jet of relatively high velocity for cropping the waste ends of the billet P when a portion of the crane C is moved transversely of the length of the billet.

Referring to Fig. 1, the travelling crane C comprises a frame having wheels |2--|2 and 2 3,-| 3 thereon by means of which the frame may move forward and backward along rails |4-|4. The frame ll carries thereon a platform |5 upon which an operator may stand and ride with the frame. The frame also supports a mo-' tor l6 and a clutch l1, with the usual operating lever l3, clutch control rod l9 and rheostat 19 for propelling the frame along the rail |4--|4 all more fully disclosed in application Serial No. 732,668, filed June 2'7, 1934, by Homer W. Jones and Edmund A. Doyle.

Carried on the frame, and forming a part of the crane C, is a pair of tracks 23-43 perpendicular to the rail |4--|4. A cross-carriage 2|, likewise forming a part of the crane C, has wheels 22--22 and 23-23 whereby it may move along the tracks 2323 on the frame perpendicularly to the movement of the frame along the rails |4--|4. The carriage 2| is moved-back and forth along the tracks 23-20 by means of a reversing motor 24 mounted in a support 25 attached to the carriage 2|, or by manually rotating a handwheel 22' fixed to an extended end of the axle on which one set of wheels 22, 23 are fixed. As shown in Fig. 2, the motor 24 is in driving engagement with a shaft 25' to which the other pair of wheels 22 and 23 are fixed. Specifically, the motor 24 is connected to a speed reducer 26 by coupling 21. The speed reducer 25 is provided with a sprocket 23 which is aligned with a sprocket 29 mounted for free rotational movement in fixed axial position on shaft 25'. A chain 29' transmits motion from the speed reducer 25 to the shaft 25'. One part 33 of a clutch is fixed to the freely rotatable sprocket 29, and another part 3| of said clutch is splined to and axially movable along shaft 25'. An operating rod 32 extends from the clutch element 3| to a position adjacent the operator's plat- .form i5.

The supporting abutment S is rigidly suspended from a horizontal slide 33 carried by longitudinal dovetailed grooves 34-34, (seeFig. 1) in the carriage 2|. The slide 33 is adjustable relatively to the carriage 2| by a. pinion 35 journalled in the carriage and meshing with a rack 33 secured to the slide 33 and extending longitudinally thereof. Thus, turning the pinion 35 will move the slide 33 forwardly or rearwardly on the carriage 2|, depending upon the direction of rotation of the pinion 35. A bevel gear 33 mounted on an axle journalled in the carriage 2| meshes with a bevel pinion 33 secured to the .end of a shaft 43 journalled in the carriage 2| and substantially perpendicular to the axis of the gear 33. By turning a handwheel 4| keyed to the shaft 43, the operator may turn the pin ion 33, the gear 33, and the pinion 35, to move the rack 35, and with it the slide 33, forwardly or rearwardly of the carriage 2|.

As shown in Figs. 2 and 3 the abutment S comprises a vertical guide 42 rigidly depending from the slide 33 and having stiffening ribs 43-43 on the rear side thereof. The connection between the guide 42 and the slide 33 is braced by angle plates 44, only one of which is shown in the drawings. The guide 42 has a groove 45 formed centrally lengthwise of the front side thereof; and unitary vertical flanges 4343 extend laterally of the guide 42 along opposite sides of the groove 45. A vertical shaft 41 held against axial movement, is journalled in the horizontal slide 33, and extends below the latter and along the groove 45. The lower end of the shaft 41 is threaded and engages threads in a vertical slide 43 having its rear face 43 in sliding contact with the front face of the vertical guide 42. Longitudinal flanges 53--5|| secured to the vertical slide 43' extend endwardly over and slidingly engage the rear surfaces of the flanges 45 on the guide 42. The shaft 41, being threaded into the slide 43, provides means for adjusting the height of the latter along the guide 42. Thus, the operator upon the platform |5 may turn the shaft 41 by means of a handle 5| to raise or lower the slide 43 with respect to the crane C and perpendicular to the 'metal surface to be treated.

a The vertical slide 43 has pivoted thereto a pair of vertically extending link-plates 52 and 53, one at each side thereof. Each link is pivoted to the slide 43 at two points axially in line one above the other, so that the links 52 and 53 are free to swing horizontally or parallel to the surface undergoing treatment. The forward ends of the links 52 and 53 are each pivoted at two points vertically in line with a vertical supporting plate 54. Since the links-52 and 53 areof the same length, they support and swing the plate 54 always in parallel relation to the slide 43. A pair of vertically aligned lugs 55 are formed at the top and bottom of the plate 54 adjacent one vertical edge on the'front face of the latter; and pivoted coaxially to these lugs are two correspondingly aligned lugs 51 formed at the top and'bottom, on and adjacent one vertical edge of the rear face of a main support memberor blowpipe carrier 53. Only one of the lugs 55 and 51 is shown in Figs. 2 and 3.

Means is provided for varying the angular position of the blowpipe carrier 53 with respect to the support 43. A pair of parallel metal strips '63 and GI are respectively secured to the opposed faces of the plate 54 and the carrier 53 and project laterally beyond the two vertical edges of the plate 54 and carrier 53. Coaxial holes are provided adjacent the ends of both strips, and "an adjustablebolt 32 passing through the strips 63 and GI, fixes the angular relation between the carrier 53 and theplate 54. As shown in Fig. 2,

' series of vertical supporting bars 64 in a manner permitting them to swing upwardly or downwardly and still remain always in vertical position.

A second vertical supporting bar 65 ,is adjustably connected to each bar 64 by means of an upper horizontally adjustable link 68 and a lower horizontally adjustable link 61. The pairs of links 86 and 61 are of equal length, and therefore carry the bar 65 always in vertical position, while permitting horizontal angular displacement thereof when the bolts which secure these links to the bars are loosened.

' The individual blowpipe heads H are narrow in order that the jets delivered by the several blow-pipes will produce a substantially continuous metal-removing stream extending completely across the face of the billet or body to be desurfaced. Obviously, the number of blowpipes used depends upon the width of the surface to be removed. The blowpipe units are separately carried by the linkage mechanism L above the billet P in the following manner: each blowpipe head H has a pair of brackets 68 and 69 secured, respectively, adjacent the upper and lower ends of its rear face. The bracket 68 has a vertical hole therethrough and the bracket 69 has a downwardly extending pin 18 formed thereon. A blowpipe head H is removably secured to each of the bars 65 bymeans of'a bolt 1| passing through the hole in the bracket 68 and into a threaded hole in the top of the bar 65, and the pin 10 enters a hole or socket 12 in the lower part of the bar 65. Since the bolt H and the .pin I0 are not coaxial, the connection between the blowpipe head and the bar 65 will be rigid. Any blowpipe head H may be quickly removed from the apparatus by unscrewing the bolt 1| and lifting the head from the bar 65.

The desurfacing gases used by the blowpipe units, e. g. a mixture of oxygen and acetylene to provide the heating fiame and oxygen to provide the oxidizing stream, are supplied individually to the units through hose connections attached to the tops of their heads H, such connections being generally indicated in Fig. 2 at 13.

For the purpose of cropping off the waste ends of billet P to provide square end edges, a cutting torch assembly T is mounted on the carriage 2| that supports the desurfacing blowpipes. As disclosed inv Figs. 2 and 3, a pair of Z brackets 14 and I5 are mounted at the upper and lower portions respectively of one side of the blowpipe carrier 59. Thebrackets. are adapted to support the cutting torch assembly T in spaced re- -lation to the carrier 59. A supporting plate 18 is fixed to the ends of Z brackets 14 and I5 opposite those which are fixed to the carrier 59. A pair of bevelled-edge tracks 18 are fixed to the forward surface of the plate 18 and form a dove-tail slide bearing with a slide 19'. A' T-sectioned member 19 is fastened to slide 18',-

.shaft is supported in bearings 85' extending from the rear surface of supporting plate 16, and it is rotated by turning a handle 88 mounted on its one end. A longitudinal slot of greater widththan the gear 84 is provided in plate 16, there- .by permitting the gear 84 to protrude therethrough for cooperation with the rack 83. Thus surfacing blowpipes.

it is seen that torch 8| may be moved downwardly into operative position relative to billet P, or upwardly out of such operative relation by turning handle 86 in one or the other direction. The torch 8| is adapted to receive oxygen and a preheating medium such as a mixture of oxygen and acetylene through the conduits 82 from the same sources that supply the gases to the de- The conduits 82 are surrounded by a wall 82' of a cooling chamber through which water is adapted to circulate.

For the purpose of preventing movement of the crane C lengthwise of the billet P when the cutting torch 8| is lowered into operative position, and therefore to prevent damage to said torch by its striking the end of said billet, means is provided for rendering the means which drives the crane C lengthwise of billet P non-operative when torch 8| is in operative position. In the embodiment disclosed, a limit switch 81, see Fig. 2, is mounted on the bracket 14 in such position that a circuit breaking handle 14 of said switch is adapted to be thrown in or out by engagement with an abutment or lug 88 on the' vertically reciprocable torch 8|. The switch 81 is wired in series with the motor l6, and upon lowering torch 8| into operative position, the lug 88 will engage handle 14 and move it to open the electrical circuit of motor I6. After the cropping off operation has been completed, the torch 8| is raised out of operative position and lug 88 thereupon moves the circuit breaking handle of switch 81 to complete the circuit for motor l6.

For the purpose of preventing the over-running of carriage 2| of the crane C, means is provided for interrupting the electrical circuit of motor 24. This has been accomplished by providing another limit switch 90 on the under portion of carriage 2|, see Fig. 2. The switch 9|] is connected in series with the electrical circuit for the motor 24, and it is provided with an operating lever 9|. stops 93 are located at each end of the track 20 defining the limit of movement of carriage 2| thereon. One leg of each angle member 93 has aflixed thereto an abutment 92 extending into the path of travel of the switch operating lever 9|. Thus, it is seen that transverse movement of the carriage 2| will be automatically discontinued in the event the operator neglects to disengage the clutch element 3| at the proper time.

Briefly, the operation of the apparatus is as follows: the blowpipe units H are assumed to be initially adjusted in line and so that the nozzles N will together deliver continuous wide associated streams of heating and oxidizing agents obliquely against and lengthwise of the billet P to be conditioned. Standing upon the platform IS with the blowpipe heads H, the cutting torch 8| and the billet P in view, the operator closes the A pair of angle members or proper switch for causing the motor 24 to rotate I by moving the rod 32 in the proper direction, to

propel the carriage 2| in the desired direction along the rails 20 and across the billet at a short distance from its end to sever the waste irregular portion and leave a square end.

After the cutting operation has been completed, the operator disengages clutch elements 30 and 3| and raises the torch 8| out of operative position, thereby closing the break in the electrical circuit of motor IS. The operator next closes a starting switch (not shown) having three buttons (forward, reverse, and stop), to start the motor l6 and then manipulates the rheostat box l9 to adjust the motor speed and pushes the control rod l9 to his right or left as required to throw in the clutch IT to move the crane C in the proper direction until the nozzles N are horizontally in line with the squared starting end of the billet P.

Vertical and horizontal adjustment of the nozzle carrier may be made by turning the handles 5|, 22 and 4|, until the nozzles are located accurately relatively to the conditioned starting edge of the billet surface. The preheating mixture is then turned on and ignited and, as soon as the previously formed straight edge of the billet P has been raised to an ignition temperature by the preheating flame, the oxidizing gas isturned on. Thereupon, the control rod I9 is moved to engage the clutch II, to propel the assembly forwardly lengthwise of the billet at the proper speed, whereby the complete top side of the billet is desurfaced.

When the top surface of the billet has been completely desurfaced, the crane frame will have reached the far end of the billet, whereupon the billet may be cropped close to this end, in amanner similar to the cropping at the starting end. When conditioning a rectangular billet with the apparatus shown, the billet must be turned about its longitudinal axis through an angle of 90 to present the next side for desurfacing, and so on until all four sides are desurfaced; but the cropping is necessary only once and at only one end for each billet, since the single or initial severing operation by the torch 8| will produce square edges at the starting ends of all four sides. After each side has been desurfaced the crane frame is returned to the initial position and ad-. justed laterally in line with the billet to start and carry through a desurfacing operation on the next side presented. Also, in machines for simultaneously desurfacing all sides of a rectangular or multi-sided billet, a single initial cropping of the billet close to the starting end provides a square edge at the starting end of each face of the billet and, since these square edges are 'all in the same plane, this insures that the desurfacing operation will start substantially simultaneously at all sides and proceed uniformly lengthwise of all sides.

The embodiment described herein and illustrated in the drawings is disclosed to indicate how the invention may be applied. Certain features of the invention may be 'used independently of others, and numerous changes may be made in the details of the apparatus here disclosed without departing from the principles of the invention. For example, other types of propelling, supporting and adjusting mechanisms may be utilized; the desurfacing blowpipe apparatus and the cutting blowpipe apparatus may be stationary and the billets may be propelled relatively thereto; and some or all features of the invention may be utilized in machines having surface-removing blowpipes disposed horizontally relatively to a vertical surface, instead of vertically relatively to a horizontal surface, and in which the cutting torch may be inclined forwardly in the direction of cutting in order to increase the rate of cutting, rather than disposed vertically as here shown.

What is claimed is:

1. A method of thermo-chemically conditioning a steel ingot bloom or billet, having an irregular end, which comprises flrst concurrently applying a high temperature heating flame and a relatively high-velocity jet of oxidizing gas against said body and progressively in a direction substantially perpendicular to its length and near said end to thermo-chemically sever said ir regular end and provide a straight square edge at the starting end of the surface to be treated; and then directly thereafter removing a layer of metal from said surface by concurrently impinging a relatively wide-temperature heating flame and a relatively wide low-velocity oxidizing stream obliquely against and progressively lengthwise of said surface to the other end of said body; and beginning such metal layer removal at such newly formed straight square edge so as to utilize the latter to assist initially in accurately aligning the impinging portions of said wide flame and said wide oxidizing stream relatively to the length direction of said surface and also to utilize said edge to concentrate the heat applied thereto by said wide flame and uniformly distribute such heat along said edge through the width of said wide flame in order to expedite the starting of the metal layer removal uniformly across the entire width heated by said wide flame.

2. A method of thermo-chemically conditioning a steel ingot bloom or billet, having irregular ends, which comprises first concurrently applying a high-temperature heating flame and a relatively high-velocity jet of oxidizing gas against said body and progressively in a direction substantially perpendicular to its length and near one of said irregular ends to thermochemically sever such irregular end and provide a straight square edge at the starting end of the surface to be treated; directly thereafter removing a layer of metal from said surface by concurrently impinging a relatively wide high-temperature heating flame and a relatively wide lowvelocity oxidizing stream obliquely against-and progressively lengthwise of said surface to the other end of said body, said flame and stream extending across the entire width of said surface; beginning such metal layer removal at said straight square edge so as to utilize the latter to assist initially in accurately aligning the impinging portions of said wide flame and said wide oxidizing stream relatively to the length direction of said surface and also to utilize said edge to concentrate the heat applied thereto by said wide flame and uniformly distribute such heat throughout the width of said body along said edge in order to expedite the starting of the irregular end, which comprises nrst concurrently ing the tour longitudinal surfaces of a rectanguapplying a high-temperature heating flame and 19.1 steel ingot, bloom or billet, having an irrega relatively high-velocity jet of oxidizing gas ular end, which comprises first concurrently apagainst said body and progressively in a plane plying a high-temperature heating flame and a substantially perpendicular to its longitudinal relatively high-velocity jet of oxidizing gas axis and near said end to merino-chemically against said body and progressively in a plane sever said irregular end and provide a square end substantially perpendicular to its longitudinal having straight square. edges, one at each of the axis and near said end to thermo-chemically starting ends of the surfaces to be treated; then sever said irregular end and provide a square directly thereafter removing a layer of metal end having straight square edges on all four from one of said surfaces by impinging a relasides; and then directly thereafter removing a tively wide high-temperature heating flame and layer of metal simultaneously from all four side a relatively wide oxidizing gas stream obliquely surfaces of said body by impinging relatively against and progressively lengthwise of said surwide high-temperature heating flames and relaface to the other end of said body: turning said tively wide oxidizing gas streams obliquely body about its longitudinal axis to present anagainst and progressively lengthwise of all four other surface to be treated; removing a layer of of said surfaces from said square end to the metal from said other surface by similarly applyother end of said body, and beginning such metal ing a relatively wide heating flame and a relalayer removal simultaneously at all four newly tively wide oxidizing gas stream against said formed straight square end edges so as to utilize other surface; and beginning each of such metal such edges to assist in initially accurately alignlayer removing steps at the straight square end ing the impinging portions of said wide flames edge of each of said surfaces so as to utilize such and said wide oxidizing gas streams relatively to straight square edges to assist initially in accurthe length directionof said surface and also to ately aligning the impinging portions of said wide utilize said edges to concentrate the heat applied flame and said wide oxidizing gas stream relathereto by said wide flames and distribute such tively to the length direction of said surface and heat uniformly along all four of said edges also to utilize said edges for concentrating the throughout the entire perimeter of said square heat applied by said wide flame and uniformly end in order to expedite the starting of the metal distribute such heat along said edges through layer removal uniformly and simultaneously the width of said flame to expedite uniform 7 across the entire width of all four sides of said starting of the metal layer removal on each of body.

the plurality of surfaces of said body. JAMES H. BUCKNAM.

4. A method of thermo-chemically condition- ALFRED J. MILLER.

. CERTIFICATE OF CORRECTION.

Patent No. 2,189,755. Februar 13, 1950.

- JAMES H. BUCKNAM, ET AL. 1 o

It is hereby certified that error appears in the printedspecification of the above nwnbered patent requiring correction asfollows: Page 11,, second column, line 20, claim 1, for "wide-temperature" read wide high-temperature; and that the said Letters Patent should .be read with this correction therein that the same may conform to the record-of the case in the Patent Office. Signed end sealed this 19th day of March, A. 1 1 m.

Henry Van Arsdale l) Acting Commissioner of Patents.

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