US2215577A - Deseaming and desurfacing process - Google Patents

Description

Sept. 24,1940. H BUCKNAM 2,215,577

DESEAMING AND DESURFACING' PROCESS Filed Jan. 14, 1939. 2 sheetswsheet l INVENTOR Z JIMfS li Boom/AM ATTOR N EY Sept 19 J. H. BUCKNAM DESEAMING AND DESURFACING PROCESS ,EiledJan. 14, 1959 2 Sheets-Sheet 2 I N VE N TO R JAMES H. BUCK/VAN llfiii'l'l.

IIIJJIIIIIIIIIIIIIIII IIIIIIIIII. IIIIIIII'II:

ATTORNEY Patented Sept. 24, 1940 ATES James H. Bucknam, Cranford, N. 3., assignor to Oxweld Acetylene Company, a corporation of West Virginia Application January 14, 1939, Serial No. 250,965

3 Claims.

This invention relates to deseaming and desurfacing and more particularly to the thermochemical treatment with oxygen of a ferrous metal body, for the purpose of removing surface defects therefrom, especially prior to subsequent rolling operations.

Heretofore it has been the practice in deseaming to remove surface defects, such as seams, cracks, scabs, overlaps, and the like, from iron and steel bodies, such as billets, ingots, blooms, and the like, by. means of a deseaming blowpipe having a single nozzle adapted to discharge a jet of oxygen along and obliquely against a ferrous metal surface for thermochemical reaction with surface metal initially raised to the kindling temperature by a concentric series of heating jets discharged from the same nozzle, and maintained at such temperature by the heat of the reactio alone or assisted by said heating jets.

Also, heretofore it has been the practice to desurface a surface area of a ferrous metal body by directing several oxygen streams from a plurality of nozzles disposed in a row or bank, along and obliquely against such area for combustion by thermochemical reaction with the surface metal.

Where a single oxygen stream is used for deseaming, a shallow groove is formed in the surface of the work; whereas when several oxygen streams are applied to the work for desurfacing,

parallel channels or grooves with ridges therebetween generally are formed.

In either case, on the work surface along the margins of the treated area, slag and waste material including molten metal tends to flow and accumulate in a thin layer or film which, when solidified, is termed a fin. The slag is not all iron oxide but contains considerable metallic iron which has been displaced in the molten state due to the heat of the reaction. It is the metal con- 40 tent of the slag which causes the same to freeze on the edge of the groove and form tenacious fins.-

Such slag or fin formations are highly objectionable because they form surface defects when rolled into the work by subsequent rolling operation, being very hard and thus injurious to the finished products such as plates, sheets, bars, and the like, into which the work is ultimately formed. Likewise, fins may tend to form on the ridges between adjacent grooves and, with such ridges, are also very objectionable, as they tend to hide underlying defects in the work surface, and increase the altitude of the ridges, whereas it is most desirable that such ridges be as low as possible because of the subsequent conformation of the material.

The nozzles in a multiple nozzle desurfacing head must be spaced apart to make room for fastening the nozzles in the nozzle block. The outside of the nozzles usually are circular and the deseaming oxygen jet passage is encircled by a 5 series of preheating jets. The desurfacing oxygen jets are, therefore, spaced apart an appreciable distance, and in the past, the nozzles used had a round outlet orifice preceded by a circular straight sided passage and there was only a small amount of intermingling of the edge portions of the oxygen streams. The oxygen jet from each nozzle made a longitudinal concave groove and between such grooves were ridges of uncut or partially cut metal which sometimes contained defective metal. The grooves at their greatest depth were deeper than usually necessary, but in spite of this some defective metal would still be left on the surface while some good metal would be removed unnecessarily. With such standard nozzles having circular orifices, it was impossible to obtain a cut of uniform depth across the surface which would remove approximately all of the defective surface metal with a minimum removal of good metal. 25

The main objects of this invention, therefore, are to provide a method of preventing or inhibiting undesirable formation or slag accumulation when, as in desurfacing or deseaming, a fluid is projected along and obliquely against a body for combustion or thermochemical reaction with ferrous surface metal; a method of inhibiting ridge and fin formation when several streams of fluid are directed along'and obliquely against the surface of a body for thermochemical reaction with surface metal; a method of preventing any undesirableform'ation attending the grooving of a surface area of a ferrous metal body with an oxidizing medium by thermochemical reaction; an improved desurfacing or deseaming process; and a process of thermochemically treating ferrous metal surfaces while inhibiting fin and ridge formation on the work. Another object is generally to improve desurfacing and deseaming by overcoming the disadvantages and difficulties of the 45 prior art in the matter of the undesirable ridge and fin formation referredto above.

, The novel process of the present invention for desurfacing preferably comprises impinging large jets of fluid along and against a work surface for 50 thermochemical reaction with surface material to form parallel shallow channels therein, and simultaneously impinging small-jets of fluid along andagainst the work surface near the outer margins of the outer channels for thermochemical 55 reaction with fin forming material discharged from said channels as aresult of said first-named thermochemical reaction, and to impinge small jets on ridges between the channels to control the size of ridge formation between said channels.

In another aspect, the novel process comprises applying a jet of oxygen along and against a work surface for thermochemical reaction with surface material to form a groove or scarf therein, and simultaneously diverting a portion of said jet of oxygen along and against the work surface at an edge of the groove or channel in such a manner as to inhibit undesirable formation, such as fin formation thereon.

The practice of the invention results in an article of manufacture comprising a ferrous metal body having a shallow groove therein that is free of fin or slag formation overlying the surface at the lateral edge or border of the groove.

Referring to the drawings:

Fig. 1 is a fragmentary perspective view of a known deseaming blowpipe in operation, the work being shown in cross-section to illustrate undesirable slag or fin formation along the opposite edges of the groove;

Fig. 2 is a view similar to Fig. 1 of a gang of deseaming ordesurfacing blowpipes in operation, to illustrate the undesirable ridge formation between grooves as well as the undesirable fin formation thereon and along a border of the outer groove;

Fig. 3 is a view in front elevation of the nozzle end of a blowpipe embodying features of this invention;

Fig. 4 is a fragmentary View in section taken on line 44 of Fig. 3;

Fig. 5 is a fragmentary view in section taken on line 5-5 of Fig. 3, and showing the relation of the blowpipe to the work undergoing surface removal;

Fig. 6 is a view similar to Fig. 3 of a modification;

Fig. 7 is a view in front elevation of another modification;

Fig. 8 is a view in section taken on line 8-8 of Fig.

Fig. 9 is a view in section taken on line 9-9 of Fig. 8;

Fig. 10 is a view similar to Fig. 9 of a modification wherein the auxiliary fluid jets are directed in parallel relation instead of inwardly;

Fig. 11 is a view similar to Fig. 10 of a further modification wherein the auxiliary fluid is conducted through an external pipe instead of an internal passage in the nozzle;

Fig. 12 is a sectional view of another modification wherein a single auxiliary fluid jet is used;

Fig. 13 is a view in front end elevation of the nozzle shown in Fig. 12;

Fig. 14 is a view in section of another desurfacing or deseaming nozzle embodying features of this invention; and

Fig. 15 is a fragmentary perspective view of a gang of desurfacing nozzles, similar to the nozzle of Fig. 14, for preventing the: formation of fins along the ridges between the channels and along the outer edges of the desurfaced area.

Iron and steel when heated to its ignition temperature will burn in an atmosphere of oxygen. This thermochemical reaction is used in the removal of defects from ferrous metal bodies and involves the formation of iron oxide which has a lower melting point than that of iron or steel. Consequently, it melts and forms a fluid slag which is blown away from the region of the is'removed in a molten state, withthe net result that more metal is removed per unit of gas consumed when preheating flames are used. The oxy-acetylene flame generally is used for providing such a source of heat. Deseaming blowpipes thus generally provide an oxygen jet to do the actual surface removal and one or more oxyacetylene flames to heat the metal to the proper temperature for the thermochemical reaction of the surface ferrous metal with the oxygen of said jet.

The United States Patent No. 1,957,351 to Samuel R. Oldham, dated May 1, 1934, entitled Method of removing metal from metal articles" is a good example of the prior art. This patent discloses another type of deseaming nozzle wherein the heating gas outlets are grouped to project the heating flame against the work surface underneath the oxygen stream.

In hand or machine deseaming with a single blowpipe, if the nozzle is held so that its axis is in a plane coinciding with the direction of movement, a relatively deep groove is formed, and incompletely oxidized molten slag is blown from the groove, resulting in parallel fins which adhere to either side of the groove. If the blowpipe is inclined laterally the formation of a fin may be minimized or controlled at the near side of the groove, but a larger fin results on the far side of the groove toward which the slag is driven.

In hand scarfing, operators also attempt to rethe deseaming nozzle over the surface of the work.

so as to impede their growth, but this is tiring on the operator, slow and unsatisfactory from an economical standpoint, because it wears away the nozzle and wastes oxygen. An untidy surface, crossed by sharp metallic fins, also impedes inspection and sometimes necessitates additional desurfacing.

In machine desurfacing involving the use of a row or bank of deseaming blowpipes, an attempt has been made to inhibit fin and ridge formations between channels, by inclining the outer nozzles inwardly so that as much as possible of the slag and molten metal tending to overflow the deseamed area is urged inwardly and the oxygen jets sweep at an angle across the ridges. An example of such attempt is shown by the United States Patent No. 2,125,179 to Edmund A. Doyle, dated July 26, 1938, and entitled Method of and apparatus for removing metal from the surfaces of metallic bodies. However, this slows down the process, faster desurfacing being obtained when the nozzles are parallel to their direction of travel. Also, fins are formed along the two outside edges of the relatively wide out.

this process there is used a blowpipe nozzle hav-' ing a central oxygen emitting passage and a concentric series of heating gas emitting passages, together with means associated with the blowpipe nozzle for projecting auxiliary oxygen jets or streams against the edges of the scarf to prevent fin formation. The auxiliary oxygen jet passages are preferably provided in the wall of the nozzle, and are so located therein as to divert a small portion of the main oxygen jet onto, and thereby reduce, the fins or ridges that are left by a nozzle or bank of nozzles of conventional construction, each having a single oxygen orifice. When these novel deseaming nozzles are used in a head, the inside, adjacent auxiliary oxygen passages are so located that there is an overlap of the diverted oxygen jets, which increases the oxidation of the ridges, While the outside auxiliary passages are so located and proportioned as most efficiently to remove the fins.

The auxiliary oxygen passages may be in the form of drilled holes or slots or pipes, that may be in parallel or inclined relationship with the main oxygen passage, and the auxiliary oxygen passages may direct a portion of the oxygen either outwardly or outwardly and downwardly or inwardly or inwardly and upwardly depending on the relative positions of the passages and the position of the nozzles in relation to the work and the particular effects desired. The auxiliary oxygen passages inhibit fin formation, while the bottom of the deseaming groove is made more nearly flat because of the spreading of the oxygen jet more evenly across the entire width of the scarf.

When a number of deseaming nozzles are used in a bank, the ridges formed between the grooves cause the cross-section of the scarfed plate to have a wavy or fiuted appearance. The deseaming head is usuallytilted so that the nozzles will be both inclined to the work and angularly disposed to the direction of travel. The auxiliary oxygen passages in such deseaming nozzles are so located that there is an overlap of auxiliary oxygen jets to reduce the ridges between the grooves. By reducing the ridges, the appearance of the work is not only enhanced, but any surface imperfections which might be hidden by such ridges are removed.

Referring to Fig. 1 of the drawings, B is a conventional deseaming blowpipe having a nozzle N provided with a central oxygen discharging passage OI surrounded by heating gas discharging passages H. The arrangement is such that when the blowpipe B is moved relative to the surface T of a ferrous metalbody W, a shallow groove G is formed in the work. As a result of this deseaming operation, fins F, F are formed from a molten mixture of slag and metal which fiows over the edges E, E of the deseaming groove G and solidifies on top T of the relatively cold work W. These fins usually form along each longitudinal side or edge E of each scarf G. The carbon content of the metal determines how difficult such fins are to remove. Steels having a low zles are used, as shown by Fig. 2, there results a plurality of parallel channels or grooves G extending across thetreated area. .Between the grooves G are undesirable ridges R having a certain amount ofv undesirable fin formation FR thereon. The outer border of the outer groove also has left thereon a fin F, as pointed out above in connection with Fig. 1. An equally important purpose of this invention is. to inhibit the ridge formation R and the fin formation FR, as well jet of oxygen for thermochemical reaction with surface material of the work W, such as a ferrous metal body, when said jet is impinged obliquely against and along the work surface T, and resulting in the formation of a shallow-groove G in the work. The nozzle N! is provided with a pair of slots S, S each in the shape of an imaginary short triangular prism in the wall of the bore OI, each slot S being positioned so that the lateral faces of the prism are disposed, respectively, at the bore OI, at the outer end P of the nozzle NI, and at the bottom of the slot: and the bases of the prism are disposed,'respectively, at the opposite sides of the slot, which sides are equally spaced from and parallel to a plane passing through the axis of the bore OI and disposed at an angle of about 45 degrees to the surface T of the work W. With this arrangement the main jet of oxygen issuing from the bore OI is provided with a pair of lateral, wedge-shaped auxiliary streams of oxygen which impinge against the work surface along the opposite edges E, E of the groove G to inhibit undesirable formation, such as ridge or fin formation or both.

The nozzle NI of the deseaming blowpipe B is provided with a concentric series of heating gas emitting passages H surrounding and concentric with the central oxygen, emitting passage 01.,

The blowpipe B is otherwise of conventional design and construction well known to those skilled in the art.

The purpose of the auxiliary oxygen streams or jets is to oxidize the fin or ridge forming material while at an ignition temperature and to further oxidize slag from the groove or scarf to facilitate its removal by brushing. My deseaming nozzle NI thus makes scarfs without the fins, especially in low carbon steel. If desired, only one auxiliary stream or sheet of oxygen may be diverted from the main oxygen passage to in hibit the formation of a fin along one border'area of the groove.

In-operation, where a single blowpipe B having the nozzle NI for deseaming or desurfacing is used, the nozzle is first held in an upright position to direct the heating jets issuing from the passages H against'the surface T of the work W to heat the same to its kindling temperature with oxygen. When the heated area of the work surface is at the kindling temperature, the oxygen ically with the ferrous surface metal and at the same time the blowpipe is tilted so as to impinge the main oxygen jet obliquely against the surface to be deseamed, as shown by Fig. 5. The nozzle NI is then advanced along the surface T to form the groove G, blowing the slag and molten metal M forwardly over the uncut surface of the base metal. At the same time the auxiliary oxygen of the sheets or streams issuing from the slots S, S thermochemically reacts with the oxide and molten metal tending to flow laterally out of the groove and over the base metal along the opposite edges of the groove, to thereby inhibit fin formation.

Where a plurality of the blowpipes or nozzles NI are used in a bank to deseam or desurface a ferrous metal body, the auxiliary sheets or streams of oxygen overlap and impinge against the work surface in the areas of ridge formation between the grooves. In such case the oxygen burns the slag and molten metal from between the grooves or reduces the ridge formation, while the outer laterally projected oxygen streams act to inhibit fin formation along the borders of the desurfaced area, leaving the base metal substantially clean and the desurfaced area substantially clean.

Referring to Fig. 6, there is shown another deseaming nozzle N2 wherein the slots S2, S2 are similar to those described above in connection with Figs. 3-5 but are disposed at an angle of 180:' degrees relative to one another instead of 90 degrees. The operation of the nozzle N2 shown in Fig. 6 is substantially similar to but not quite as eifective for the purpose intended as that shown by Figs. 3-5. The blowpipe nozzle N2 has a central oxygen emitting passage 02 and a concentric series of heating gas emitting passages H for scarfing a plane surface, while the slots S2, S2 in the wall of the oxygen emitting passage project auxiliary sheets of oxygen against the edges of the scarf to prevent any undesirable formation, such as ridges or fins, thereon.

Referring to the modification shown in Figs. 7, 8 and 9 of the drawings, the deseaming or scarfing nozzle N3 is provided with a pair of auxiliary oxygen passages S3, S3 which lead from the main oxygen bore 03 at l5, l and are dis-- posed and arranged to direct auxiliary oxygen jets inwardly along and against the edges of the uncut area of the work to control slag formation thereon. In this nozzle there are also provided heating gas passages H surrounding the main oxygen passage 03 in concentric relation.

In operation, the auxiliary jets of oxygen issuingfrom thenozzle N3 sweep at an acute angle inwardly and slightly downwardly across the base metal at the borders of the groove formed by the main oxygen jet issuing from the passage 03. The auxiliaryoxygen jets blow the oxide and molten metal tending to flow outwardly, inwardly back into the path of the deseaming operation, and thus assist the latter, without harming the base metal while at the same time physically and chemically inhi biting the formation of fins;

A modification of the nozzle of -Figs. '7, 8 and 9 is shown in Fig. 10 wherein the nozzle N4 is provided with auxiliary oxygen discharging passages S4, S4 which are disposed and arranged to direct the auxiliary oxygen jets in parallel relation over the opposite edges of the work surface adjacent the groove made by the main oxygen jet. Thus, as the nozzle is advanced, parallel auxiliary oxygen jets are impinged along and obliquely against the work surface at the borders of the groove formed by the impingement of the main deseaming oxygen jet along and obliquely against such surface. These auxiliary jets also successfully inhibit fin formation.

, In the modification of Figs. 12 and 13, the deseaming nozzle N5 has an auxiliary oxygen pas- :age 05 that is connected at its inlet end l8 to the main oxygen passage 05, and has its outlet portion-parallel with said main oxygen passage 05. This auxiliary passage S5 directs an oxygen jet down along the edge of the scarf and tends to keep the molten metal from flowing over base metal at the edge of the scarf, and oxidizes the molten metal that does not reach the edge. An 5 operator can deseam faster with this nozzle than with a conventional deseaming nozzle since the fin inhibition is substantially automatic. The deseaming nozzle N5 shown in Figs. 12 and 13 is otherwise substantially similar to a convention-' al deseaming nozzle, being provided with oxyacetylene heating gas passages H surrounding the central oxygen passage 05; the auxiliary oxygen passage S5 occupying. the position of one of the oxy-acetylene passages. The blowpipe nozzle N5 is preferably held so that it is inclined to the direction of travel, the auxiliary oxygen passage S5 being positioned so that its oxygen jet impinges along the edge of the deseaming groove at the far side thereof, to thus thermochemically react with the surface material that tends to flow out of the groove. In this way fin formation along the far side of the groove is substantially entirely eliminated. The angle and direction of impingement of the auxiliary oxygen jet 25 may be controlled readily by the operator by manipulating the blowpipe.

Referring to Fig. 11, there is shown a blowpipe nozzle N6 for deseaming, the nozzle being provided with a branch pipe or conduit C connected at its inlet end to the main oxygen passage 06, the branch conduit C being curved inwardly to direct an auxiliary jet of oxygen inwardly and downwardly against the edge of the area undergoing desurfacing treatment by the main oxygen jet. This nozzle is also provided with heating gas passages H surrounding the main oxygen passage 06 in concentric relation. If desired, the nozzle shown in Fig. 11 may be provided with two branch conduits for diverting auxiliary jets of oxygen from the main oxygen passage 06. The operation of the device. is substantially similar to that described above in connection with the blowpipe shown in Figs. 12 and 13.

Referring to Fig. 14, the desurfacing or deseaming nozzle N1 is provided with a main oxygen bore 01 and with a pair of outwardly inclined auxiliary oxygen bores 81 for diverting some of the oxidizing fluid from the main bore obliquely against and along the surface of the work to inhibit ridge and fin formation. When used in a deseaming head the outwardly inclined auxiliary oxygen jets coact in controlling ridge formation between the scarfing grooves made by the thermochemical re-, action of the main oxygen jets with ferrous surface material of the work. The outer nozzles are provided with auxiliary oxygen passages S1 for directing auxiliary jets of oxygen along and against the surface T of the work W adjacent the area undergoing deseaming treatment to inhibit fin formation F.

Referring to Fig. 15, a plurality of nozzles N! are shown mounted in a bank so that the fininhi-biting oxygen jets issuing from the auxiliary oxygen bores S! are directed along the ridges between the channels formed by the main oxygen jets and are directed along the outer edges of the outer channels. Thefin-inhibiting jets prevent the formation of fins on the ridges and along the outer edges of the desurfaced area,

While there is great similarity between the deseaming nozzles having auxiliary oxygen jets for fin control and the desurfacing nozzles having auxiliary oxygen jets for ridge control, there is a decided difference between these nozzles as to 75 where and how they are used and as to the percentage of the total oxygen stream which is diverted into the auxiliary jets. The deseamingvent the formation of fins by a combination of a blowing off of the molten slag or metallic oxide and further oxidation of a small amount of molten metal in the slag. The desurfacing nozzles for ridge control divert a larger percentage of the total desurfaci'ng oxygen in their auxiliary jets to oxidize the usual ridges.

While the nozzles shown in Figs. 3-6 are intended primarily for ridge elimination, and the nozzles shown in Figs. 1-13 are intended primarily for finremo-val, it will be understood by those skilled in the art that the primary use of these nozzles may be changed by changing the nozzle proportions to vary the amount of oxygen in the auxiliary sheets or jets. The nozzles shown in Figs. 3-6, inclusive, give much better results when used for ridge control than the old nozzles having round orifices; the ridges being greatly reduced and the grooves being more nearly fiat by virtue of their operation. The nozzle shown in Figs. 3-5 is especially useful for scarfing around the corners of a billet in which case such nozzle is placed at the end of a bank of nozzles adapted to scarf a lateral surface, to project an oxygen stream at least partially around the billet corner or edge.

The invention is applicable to the deseaming or desurfacing treatment of ferrous metal bodies of low carbon alloy and high carbon steels, both cold and while hot and by machine or hand operation. By eliminating fin and ridge formations the resulting product is substantially free of surface defects, and in the practice of the invention no more oxygen is used than in the past where ridges and fins were formed, and substantially less than where it was attempted unsuccessfully to reduce ridge and fin formation.

What is claimed is:

L-Process which comprises impinging a large jet of oxygen along and obliquely against the surface of a ferrous metal body for thermochemical reaction with surface material to form a groove in said surface, at least the portion of the surface impinged being at the oxygen ignition temperature; and at the same time impinging a relatively small jet of oxygen obliquely against said surface along at least one edge of said groove to inhibit undesirable fin formation along said edge by reaction with fin-forming material discharged from said groove by said large jet, said relatively-small jet being of such volume and character that it is substantially non-reactive with the surface metal of said body.

2. Process which comprises applying a jet of oxygen along and against the surface of a ferrous metal body for thermochemical reaction with surface material to form a groove in said surface, at least the portion of the surface impinged being at the oxygen ignition temperature; and simultaneously diverting a relatively small portion of said jet of oxygen and directing said relatively small port-ion of oxygen along and against said surface at an edge of said groove to inhibit undesirable fin formation thereon by reaction with fin-forming material discharged from said groove thermochemical reaction with surface material to form a plurality of parallel adjacent channels in said surface, at least the portion of the surface impinged being at the oxygen ignition temperature; and at the same time, impinging relatively small jets of oxygen obliquely against said surface between said channels and along the outer edge of at least one outerchannel to inhibit undesirable fin formation between saidchannels and along said outer edge by reaction with finforming material discharged from said channels by said large jets, said relatively small jets being of such volume and character that they are substantially non-reactive with the surface metal of said body.

. JAMES H. BUCKNAM.

Images