US3264445A

US3264445A - Weld overlay

Info

Publication number: US3264445A
Application number: US311290A
Authority: US
Inventors: Roman F Arnoldy
Original assignee: R I PATENTS Inc
Current assignee: R I PATENTS Inc
Priority date: 1963-09-23
Filing date: 1963-09-23
Publication date: 1966-08-02
Anticipated expiration: 1983-08-02

Description

ug. 2, 1966 R. F. ARNOLDY 3,264,445

WELD OVERLAY Filed Sept. 23, 1963 4 Sheets-Sheet l /50/7700 /I Arno/dy INVENTOR.

ug- 2, R966 R. rf. AnNoLnY 3,264,445

WELD 'OVERLAY Filed Sept. 25, 1963 4 Sheets-Sheet 3 INVENTOR.

BY W f @m ug. 2, 1966I R. F'. ARNOLDY WELD OVERLAY Filed Sept. 25, 1963 4 Sheets-Sheet 4 @Oman f.' Arno/dy INVENTOR United States Patent O Fice 3,264,445 WELD OVERLAY Roman F. Arnoldy, Houston, Tex., assigner to R. I. Patents, Inc., Houston, rTex., a corporation of rTexas Filed Sept. 23, 1963, Ser. No. 311,290 Claims. (Cl. 219-76) The present invention relates to improvements in weld overlaying and more particularly relates to methods of and means for weld overlaying by which improved and advantageous results are obtained.

In my United States Patent No. 3,076,888 there is disclosed and claimed methods of producing weld coatings or fusion welds and in my United States Patent No. 3,060,307 there is disclosed and claimed a suitable apparatus for depositing predetermined measured amounts of electrodes and metal particles by which predetermined compositions of alloy weld overlays are obtained with very little penetration of the base metal, and hence, a minimum of dilution of the alloy overlay by the base metal. It would be highly advantageous, however, to provide a method of and apparatus for weld overlaying in which the weldable amount of the pile is considerably increased, one which permits the use of moderate forward travel speeds while obtaining greater increased deposition rates and allowing thorough melting and mixing of the granular materials and electrodes to produce a uniform alloy analysis, one in which a mixing action is provided which more thoroughly melts and mixes the ingredients and in which the bead edges are smooth and straight and trapping of flux or oxides is avoided between the beads when overlapping.

It would be further highly advantageous to provide such a method of and means for providing weld overlays on a base metal in which a complete bond with a very small, easily controlled and fully predictable penetration is obtained thereby readily providing commercial overlaps of high analysis and accuracy.

The present invention is directed to such a method and means.

It is therefore an object of the present invention to provide a method of and means for producing weld overlays in which the amount of deposition of metal particles is materially increased and which allows a much higher deposition rate without impracticable and unworkable high travel speeds.

Yet a further object of the present invention is the provision of a method of and means for producing weld overlays in which weldable amounts of the weldable particles are very greatly increased, yet a relatively low forward travel speed is permitted to insure thorough melting and mixing of the granular materials and electrodes thereby producing a uniform alloy analysis.

Still a further object of the present invention is the provision of such a method and means which produces a stirring action to the puddle which results in a thorough melting and mixing of the ingredients of the puddle.

Yet a further object of the present invention is the provision of such a method and means by which smooth and straight bead edges are provided and in which llux or oxides are not trapped between the beads when overlapping.

Still a further object of the present invention is the provision of a method of producing weld overlays in which there is substantially no penetration of the base plate or metal by the overlay material, yet there is complete bonding between the overlay and the base metal.

Yet a further object of the present invention is the provision of such a method of weld overlaying in which there is substantially no penetration of the base metal yet complete bonding of the overlay with the base metal in 3,264,445 Patented August 2, 1966 an easily controlled and fully predictable manner so as to readily provide overlays of high analysis Iand accuracy by commercial operations. l

It has been determined that the composition or analysis of beads welded sometimes has composition or structure variations, or both between the sides of the bead and its center. For example, examination of a bead of 18-8 stainless steel shows up to twice as much ferrite (free iron) in the austenitic mixture may be present at the edges as in the center of the bead. A free swinging magnet passed close to the surface readily identities these areas by swinging to the bead edges. It would be highly advantageous to provide a method of and means for welding a bead in which the composition and structure of the bead is uniform. One aspect of the present invention is directed to such a method and means.

Accordingly, it is yet a further object of the present invention to provide a method `and means by which a bead or overlay is welded to a surface in which the composition and structure of the bead is uniform and of a predetermined closely controlled composition or analysis.

Other and further objects, features and advantages of the present invention will be apparent from the following description of presently-preferred embodiments thereof, taken in conjunction with the accompanying drawings, in which like reference numerals designate like parts throughout the several views, and where,

FIGURE 1 is a diagrammatic View illustrating a method of weld overlaying ofthe prior art,

FIGURE 2 is a schematic view, similar to FIGURE 1, illustrating a method of weld overlaying according to the present invention and illustrating the increase in weldable particles when overlaid to the base in a single pass over those of FIGURE 1,

FIGURE 3 is a fragmentary, side elevational view, illustrating suitable apparatus for oscillating the electrode illustrated in FIGURE 2,

FIGURE 4 is a sectional view taken along the line 4 4 of FIGURE 3,

FIGURE 5 is a sectional view taken along the line 5 5 of FIGURE 4,

FIGURE 6 is a View similar to FIGURE 5 illustrating a modification,

FIGURE 7 is a view similar to FIGURE 3 illustrating a modification,

FIGURE 8 is a view taken along the line 8 8 of FIGURE 7,

FIGURE 9 is a fragmentary View, similar to FIGURE 7 illustrating a still further modification,

FIGURE 10 is a view similar to FIGURE 9 illustrating yet a further modification,

FIGURE 11 is a diagrammatic view illustrating the method of obtaining substantially no penetration of the base metal yet at the same time obtaining substantially complete bonding of the weld overlay,

FIGURE 12 is a side sectional view illustrating a bead or overlay welded to a surface,

FIGURE 13 is a view taken along the line 13--13 of FIGURE 12,

FIGURE 14 is a view illustrating means for depositing weld particles resulting in uniform composition and structural beads or overlays,

FIGURE l5 is a side view of the funnel illustrated in FIGURE 14,

FIGURE 16 is a view taken along the line 16-16 of FIGURE 15, and

FIGURE 17 illustrates the funnel of FIGURE 14 being oscillated transversely of its travel path.

Referring first to FIGURE l, a metal base member or plate 10 is illustrated upon which is placed particles of alloy material 12 and an arc is struck between the electrode 14 and the pile of weldable particles 12 to melt the pile while feeding the electrode 14 at a predetermined rate thereby providing a weld overlay on the base metal 10 of a predetermined composition with a minimum amount of penetration of the base metal 10 and hence a minimum amount of dilution of the resulting weld overlay by the metal -of the base 10. This is generally described and claimed in my United States Patent No. 3,076,888 to which reference has previously been made.

In FIGURE 1 there is no oscillation or movement in a lateral direction of the wire electrode 14. When weld overlaying without oscillation of the electrode 14 the maximum width of the bead is approximately 5A; inch since this is about as far as the arc will reach =on either side of a non-oscillated electrode. Hence, the pile of weldable particles can have a maximum width of about 5A; inch in order to be completely melted by the arc. The pile height then will be about 5/16 inch since the angle of repose of the granular or particular weldable material in the pile 12 is about 45 This results in a volume of granular composition per lineal inch of cubic inch. At a composition bulk density of .12 pound per cubic inch, the weight would be .0117 pound. In order to weld at a 3 to 1 ratio the wire 14 used in one inch would be .0039 pound per inch.

As travel speeds of the wire electrode 14 increase above 15 inches per minute, mixing can become less complete, the surface becomes rougher and the bead edges become irregular. Thus, using 15 inches per minute travel s-peed of the wire electrode 14 to obtain a quality deposit, the rate becomes .05 8 pound of wire per minute. This would require the use of a 1/16 inch wire electrode and would result in a deposition rate of only .234 pound per minute or 14 pounds per hour at a practical travel speed.

From the foregoing, it is readily apparent that the volume and weight of the deposited pile 12 is generally proportional to the square of the height or width of the pile, and that the use of a wider pile permits higher powder to wire ratios and high deposition rates without requiring impractical and unworkable high travel speeds of the wire electrode 14. This is accomplished by oscillating the wire electrode 14 as hereinafter set forth.

Referring now to FIGURE 2, where the reference letter a has been added to the numerals designating corresponding parts in FIGURE 1 for convenience of reference, the width of the pile 12a has been increased to as much as several inches. Since the pile weight is proportional to the square of the width of the pile 12a, the weldable amount is very greatly increased. For example, using a pile width of 1% inch would require about one inch oscillation of the wire 14a to provide a satisfactory weld overlay on the base a. The powder weight per inch of length now becomes 1% X5/s 1/2 1=.39 cubic inch .l2 pound per cubic inch=.0468 pound per inch. Wire deposition at a 3 to l ratio becomes .0156 pound per inch at 15 inch per minute travel speed of the wire electrode 14a or a deposition of 4 times as much material by making the pile width twice as much as that of the pile 12 in FIGURE 1 and thus allows use of a i732 inch wire. Further, the use of still larger piles will allow use of electrode wires of very large sizes with deposition rates proportionately higher, as for example a 1A inch wire allows a deposition rate of 3.75 pounds per minute or 225 pounds per hour with 2.5 inches wide oscillation.

Advantageously, the oscillation of the wire electrode 14a, when combined with arcing to the top of the pile 12a, permits the use of relatively low forward travel speeds of the electrode 14a which results in more thorough melting and mixing of the granular alloy materials of the pile 12a and electrode wire 14a producing a uniform alloy analyses, since the weld puddle is fluid for a considerably longer period of time than in the method exemplified by FIGURE 1, without any substantial contamination by the base metal.

In addition, the travel of the electrode 14a over the puddle formed by the electrode 14a and the pile 12a of granular alloy materials produces a stirring action which more thoroughly melts and mixes the components. Since a low forward speed of the electrode 14a is utilized, the bead edges become smooth and straight and prevent trapping of uid or oxides between beads when overlapping.

Preferably, the wire electrode 14a should be oscillated in pendulum fashion, so that the end of the electrode 14a rises at each end of its travel at the sides of the pile 12a which prevents short circuiting against a previous bead welded to the base on one side and on the free side gives a momentary high voltage which smooths out the edge or bead at that side.

Referring now to FIGURE 3, an apparatus according to the invention is illustrated for obtaining the pendulum like oscillation of the electrode, -to which the reference letter b has been added to parts corresponding to those of FIGURE 2. In this embodiment a generally tubular body 16 is provided to which is threadedly or otherwise secured the nozzle 18 through which the wire electrode 14b extends. In this embodiment variable linear oscillation of the wire electrode 14b is obtained by utilizing the crank 20 consisting of the crank arm 22 pivotably secured by the pivot 24 to the body 16 and the crank arm 24 is secured to the rod 26 which extends through the guide 28 and is connected to the follower 30 which slides in the milled heart-shaped slot 32 of the constant displacement cam 34. Thus, rotation of the cam 34, by any suitable means not shown, causes reciprocation of the rod 26 which, through the crank 20, causes a pendulum-like oscillation of the body 16 and hence, the wire electrode 1419i.

In the arrangement illustrated in FIGURE 3 there is provided means for varying the linear oscillation of the electrode 14h. This is accomplished by having the arm 22 and the rod 26 pivotally connected by means of the

pivots

36 and 38, respectively, to the arm 24 and, provided within the hollow arm 24 is a pivot 40, which is fixed by means not shown, secured to the movable member 42, the position of which is adjusted by -the adjusting screw 44. Thus, adjustment of the adjusting screw 44 causes a movement of the arm 24 which, in turn, varies the width of the oscillation of the electrode 14b.

If desired, of course, the linear oscillation of the wire electrode 14b may be varied by any suitable means. For example, with reference to FIGURE 6, the reference letter c has been added to parts corresponding to those of FIG- URE 3, a fixed crank 20c is -provided and an additional arm 21 is connected to the body 16e rather lthan the crank arm 22 as illustrated in FIGURE 3. If it is desired to change the width of the oscillation of the wire electrodes 14C in this embodiment, diiTerent size cams, such as illustrated in FIGURE 3, are utilized.

In some instances it may be desirable to change the direction of oscillation of the wire electrode 14b. Such an arrangement is illustra-ted in FIGURE 5 to which reference is now made and in which the reference letter d has been added to parts corresponding to those of FIG-

URES

3 and 6. In this embodiment, the arm 21d is directly connected to the cam arm 26d without any crank arrangement so that oscillation of the body 16d and hence the wire electrode 14d is in the direction illustrated which is generally at right angles to the direction of oscillation of the wire electrode 14C in FIGURE 6 and 14h in FIGURE 3.

No further description is given of the means for oscillatingthe body, .and hence the wire electrode, in these views as a wide variety of arrangements may be utilized as desired and to accommodate the conditions of use.

Referring now to the details of construction of the apparatus of FIGURES 3 and 4, and with particular reference to FIGURE 4, the upper end of the body 16 is enlarged, as at 48, and is provided with the' front and.

back pivot members 50 and 52. A fixed body member 54, provided with the flat slide surfaces 56 and 58, which engage the inner flat slide surfaces 60 and 62, respectively, of the pivot members 50 and 52, is secured by means of the shoulders 64 to the body 66 and by the set screw 68.

Disposed in the fixed member 54 is the passage 70 which communicates with the passage 72 in the body 16 and in the enlarged body portion 48 and with the passage 74 in the nozzle 18 through which the wire electrode 14b slidably extends. The inwardly projecting portion 76 in the inner portion of the enlarged portion 48 of the body 16 terminates at .the axis of they pivot so that there is essentially no motion at the point the Wire enters the passage 76 and has a generally tapered opening 78 so that as the enlarged body portion 48 and the body 16y are oscillated the wire electrode V14b can be threaded into the passage 76.

There are provided a pair of pivot pins 80 and 82 which pivotally secure Athe large body portion 48 to the stationary body member 54 so that only the large body portion 48, the body 16 and the nozzle 18 are `oscillated and the remainder of the body parts remain fixed with the body 66 of the feeder.

As illustrated, a tube 84 is provided through which the granular alloy weld materials making up the pile 12b are deposited in advance of the travel of the nozzle 18 and, for submerged welding, a tube 86 is provided to deposit flux 13 on -top of the pile 12b of particulate weld material. If desired, and as illustrated, the

tubes

84 and 86 may be secured to the body 66 and remain stationary, the openings in these tubes being sufficiently large -to provide the desired width of pile 12b and flux 13 for the oscillation of the wire electrode 14b so that only the electrode 14b oscillates. The remainder of the welding assembly may be the same as illustrated in my U.S. Patent No. 3,060,307 so that measured amounts of wire electrode 14b and amounts of granular material making up the pile 12b and flux 13 are deposited on the work or base metal b which is to be provided with an overlay bonded to its surface. Accordingly, no further details of the feeder arrangement is given or deemed necessary.

Preferably, the electrode 14b, .and hence the body 16 and the nozzle 18 should be directed at about a 20 angle in a trailing direction to the surface of the work 1411.

If desired, either or both the tubes for the metal pile and flux may be fixed and the entire body of themetering or feeder head for `the wire electrode, granular metal pile and flux oscillated. Su-ch an embodiment is illustrated in FIGURES 7 and 8, to which reference is now made, and -to which the reference letter e has been added to numerals designating parts corresponding to those of FIG- URES 3 yand 4. In this embodiment the body 66e is secured to a pivot shaft 22e which is oscillated by a means of a constant displacement cam, not shown, such as illustrated in FIGURE 3. The pivot shaft 22e is journalled by means of the anti-friction assembly 88 within the boom 90 by which the travel of the metering head is accomplished and which supports the various parts in relation to the work 10e.

Connected to the boom 90 by means of the bracket 92 is the funnel 94 which isv maintained in a stationary position and which receives from the tube 84e the particulate metal alloying materials for deposit on the work 10e as the pile 12e. The funnel 94 is of sucient size to receive the alloying particles from the body 66e through the tube 84e during its oscillation as best illustrated in FIGURE 8.

A similar arrangement is provided for the ux tube 86e, but because of space limitations, only the funnel 86e is illustrated.

The arrangement of the electrode and tubes for providing particulate or granular weldable material may be varied considerably as desired and .to accommodate conditions encountered in use. Such modified arrangements are illustrated in FIGURES 9 and l0, to which the reference letters f and g, respectively, have been added 4to numerals designating corresponding parts in the preceding figures.

Referring iirst to FIGURE 9, an arrangement is illustrated in that .the flux tube 861 is disposed behind the electrode 14]c but the ux tube 86f is arranged so that the ilux flows across the wire electrode 18)i as it is oscillated transversely of the direction of travel.

In FIGURE 10, the flux tube 86g is arranged concentric with land about the nozzle 18g so that the flux 13g flows `onto the pile 12g of particles of weldable material and is oscillated with the wire electrode 14g.

.No further parts are illustrated in FIGURES 9 and l0 as the remaining parts are the same and operate in lthe same manner as in preceding views land no further descri-ption is deemed necessary or given.

As previously mentioned, in producing Weld overlays on steel or other metal plates, there has been some difiiculty in controlling the amount of penetration and it has been dicult to obtain the values desired, that is, provide complete bonding with minimum penetration. As an example of one set of welding conditions, utilizing the process set forth in my United States Patent No. 3,076,888, no penetration of the base -plate is obtained, however, close control of current, base preheat, travel speed and other factors are necessary to insure complete bonding without penetration as an incremental increase in current causes penetration to occur, land the range of current setting between 1/64t inch penetration and l/ inch penetration is small. It would be highly desirable to produce a bond with a very small and easily controlled and fully predictable penetration. In this embodiment of 4the invention the surface of the work or metal base is prepared by suitable means so as to have an exposed surface `area of 11/2 to 4 times the normal flat or projected area of the surface. By a normal at surface is meant one that has a surface of R.M.S. or less, average.

Referring now to FIGURE 1l, in which the reference letter h has been added to reference numerals designating corresponding parts throughout the preceding views, a series of thread like serrations are provided, such as by machining, in the plate or work piece 10h. These may be rolled, the `surface may be blasted with rough material, such as flint and the like so that the exposed surface is 11/2 to 4 times more than that of a generally flat surface. In the serrations 15 illustrated in FIGURE l1, Ia distance of between 1&4 to '0732 of an inch between crests of the thread, and a distance of from 1//64 inch to 1/16 inch between the crest and the root are satisfactory to provide an exposed surface area of 11/2 to 4 times the normal flat or projected area.

When utilizing the increased exposed surface area within the range set forth, the temperature of the weld overlay is sufficient to melt .the narrow projections of the surface and cause bonding thereof to the work in a uniform manner whereas the same temperature of the molten overlay material would not be sufciently high to produce penetration and uniform bonding of the plate if the surface were not so prepared.

The preparation of the exposed surface of the base or work is particularly advantageous when combined with oscillating the electrode and forming an -arc between the electrode and the top of the pile, all as previously described.

This is particularly advantageous in producing overlays of high analysis accuracy, for example an overlay of AISI type 304L stainless steel. This material has a carbon content of .04 maximum for an overlay. The usual base metal will have .25 to .40% carbon.

Percent Carbon from overlay 2/3 .02:.0133 Carbon from base metal 1A .36=.l2

Total .1333

This amount is over three times that allowed to make 304L stainless steel.

Similarly, the dilution effect will cause the amounts of other elements to fall out of the allowable range. Thus, by controlling the penetration which is readily and easily accomplished, overlays of high analysis vaccuracy within allowable amounts are readily obtained.

As previously mentioned, the composition or structure or both of the bead or overlay varies between its center and edges. Referring now to FIGURES 12 and 13, in which the reference letter i has been added to reference numerals designating parts corresponding to those of the preceding views, the overlay or bead 11i of 18-8 stainless steel is shown welded to the work or base 10i. The sides x of the overlay or bead 11i have about twice as much ferrite (free iron) as the center y as determined by the test previously mentioned.

To overcome this disadvantage and to prevent this condition from happening, and with reference to FIG- URES 14, l and 16, in which the reference letter j is added to reference numerals designating corresponding parts of the previous gures, there is provided a funnel 84j which deposits weld particles 12j on the work or base j in such a manner so that there are more weld or alloy particles at the edges than in the center thus requiring less flow of weld or yalloy material to the edges from the center to complete the mixture. To this end, a plow-shaped or generally triangularly-shaped member- 85]' is provided at the trailing end of the funnel 84j which extends transversely of the path of movement of the funnel 84j. As best seen in FIGURE 14, this causes the metal pile 12j to be deposited on the work 10j in the form of two triangular metal piles 13j and 15j which intersect one another. Preferably, the angle z of the sides of the projection or plow 85]', is about twice the angle of repose of the granular metal pile or weld particles 12j. In most cases, this is about 45. Any desired shaped member, however, may be used which deposits enough metal on the sides to avoid nonuniform composition or structure of the bead or overlay.

In order to allow for the spreading 'action of the projection or plow 85j, the funnel or tube 84j may be elongated to have a length greater than its width, for example, a length twice its width, as best seen in FIGURES 15 and 16.

In some cases it may be desirable to oscillate the funnel or tube. Such an arnangement is illustrated in FIGURE 17, to which reference is now made and in which the reference letter k has been added to reference numerals designating parts corresponding to those of the preceding figures. It is noted that the

sides

13k and 15k of the pile 12k have more weld particles than its center portion. In this embodiment, the funnel or tube 85k is connected to the portion of the assembly which oscillates, such :as the body member 66. The opening in the funnel or tube 84k should be sufficiently elon gated or narrowed in its direction of travel to prevent throwing weld particles out of the effective oscillatory path of the electrode.

Similarly, in oscillating the tube or funnel for depositing weld particles or flux in the embodiments illustrated by the preceding iigures, the opening is elongated and narrowed in lthe direction of travel. For example, in FIGURES 7 and 8, the bracket 92 and funnel 94 would be eliminated and the tube 84e extend to the pile 12e, :as in FIGURE 4, and the opening of the tube 84e elongated and narrowed, yas previously described.

It is desirable in these various embodiments of the invention to bring the weld particles into the weld zone at a point which is of less distance from the arc than the length of the molten puddle and one aspect of the invention is directed thereto. This is particularly advantageous where there are changes or fluctuations in travel speed or rate of wire feed while the electrode is traveling from one point over the distance to the point of introduction of the pile of weldable overlay particles on the work or base will vary within the distance between the electrode and the point of weldable particle deposition. If this distance is greater than the molten puddle length, the analysis can vary outside the specified range. If this distance is shorter than the puddle length, the smaller .and greater amounts of weldable overlay particles are integrated into the same puddle and cancel out the variation.

Combining this aspect lof the invention with the other aspects thereof insures uniform composition of predetermined analysis land structure of the overlay with relatively fast rates of deposition land greater thickness of the -overlay and a minimum of dilution of the overlay with the base metal, but with good bonding.

The present invention, therefore, is well suited and adapted to attain the objects land ends yand has the advantages and features mentioned as well as others inherent therein.

Numerous changes may be made inthe details, arrangement of parts, and steps of the invention which is to be limited only by the spirit thereof as dened by the scope of the appended claims.

What is claimed is:

1. A method `of producing a weld overlay on the surface of a base comprising,

placing on the surface of the base a pile of electrically conductive, weldable overlay particles in a predetermined amount, the width of the pile being in excess of that which can be completely melted by a linearly moving electrode without substantial penetration of the base,

creating an arc from an electrode to the upper porti-on of the pile, and

oscillating the elect-rode transversely of the pile while melting and moving the electrode along the length of the pile at a speed corresponding to the linearly moving electrode thereby melting the pile and a thin skin of the base and bonding the overlay of predetermined composition to the base without substantial dilution of the overlay by the material of the base. 2. The method of claim 1 where, the surface has an exposed area of about 11/2 to about 4 times that of a substantially flat surface. 3. A method of producing a weld overlay on the surface of a base comprising,

placing on the surface of theV base a pile of electrically conductive, weldable overlay particles in a predetermined amount, the width of the pile being in excess of that which can -be completely melted by a linearly moving electrode without substantial penetration of the base, the height of the pile being substantially the height of the material as determined by the angle of repose of the particles,

creating an arc from an electrode to the upper portion of the pile, and oscillating the electrode transversely of the pile while melting and moving the electrode along the length of the pile at a speed corresponding to the linearly moving electrode thereby melting the pile and a thin skin of the base and bonding the loverlay yof predetermined composition to the base without substantial dilution of the overlay by the material of the base. 4. The method of claim 3 where, the surface has an exposed area of about 11/2 to about 4 times that of a substantially flat surface. 5. A method of producing a weld overlay on the surface of a base comprising,

depositing on the surface of the base a pile of electrically conductive, weldable overlay particles in a predetermined amount, the width of the pile being in excess of that which can be completely melted by a linearly moving electrode without substantial penetration of the base,

depositing flux over the pile,

creating an arc from an electrode t-o the upper portion of the pile, and

oscillating the electrode transversely Iof the pile while melting and moving the electrode along the length of the pile at a speed corresponding to the linearly moving electrode thereby melting the pile and a thin `skin of the base and thereby bonding the overlay of predetermined composition to the base Without substantial dilution of the overlay by the material of the base.

`6. The method of claim where the surface has an exposed area from about 11/2 to about 4 times that of a substantially flat surface.

7. A method of producing a weld overlay on the surface of a base comprising,

depositing on the surface of the base a pile of electrically conductive, weldable overlay particles ,in a predetermined amount,

the width of the pile being in excess ,of that which can be completely melted by a linearly moving electrode without substantial penetration of the base,

the height of the pile being determined by the angle of repose of the weldable overlay particles,

depositing a flux over the pile,

creating an arc from an electrode to the upper portion Iof the pile, and

oscillating the electrode transversely of the pile and while melting and moving the electrode along the length lof the pile at a speed corresponding to the linearly moving electrode thereby melting the pile and a thin skin of the base and thereby bonding the overlay of predetermined composition to the base Without substantial dilution of the overlay by the material of the base.

8. The method of claim 7 Where the surface has an exposed area from about 11/2 to about 4 times that of a substantially at surface.

9. A method of producing a Weld overlay on the surface of a base comprising,

depositing on the surface of the base a pile lof electrically conductive, weldable overlay particles in a predetermined amount, the sides -of the pile containing more of said particles than the center,

the Width of the pile being in excess of that which can be completely melted by a linearly -moving electrode without substantial penetration of the base,

creating an arc from an electrode to the upper portion of the pile, and

oscillating the electr-ode transversely of the pile at a speed corresponding to the linearly moving electrode while melting and moving the electrode along the length of the pile thereby -melting the center and side of the pile and a thin skin of the base and bonding the overlay Iof predetermined substantially uniform compositi-on and structure without substantial dilution of the overlay with the material of the base. 10. The method of claim 9 in Which the sides of the pile, when viewed transversely, are generally in the form of triangles and the center of the pile is formed by the intersection of the inner sides of the triangles.

11. The method of claim 10 Where the sides of the triangles are generally at the angle of 4repose of the overlay particles. i

12. A -method 'of producing a weld overlay on the surlface of a base comprising,

depositing 4on the surface of t-he base a pile of electrically-conductive, weldable overlay particles, and

creating an arc from an electrode to the upper portion of the pile thereby providing a molten puddle, the point of depositing the weldable overlay particles being less distance from the arc than the length of the molten puddle.

13. A method of producing a Weld overlay on the surface of a base comprising,

depositing on the surface of the base a pile of electrically-conductive, weldable overlay particles, creating an arc from an electrode to the uppe-r portion of the pile thereby providing a molten puddle,

the point of depositing the weldable overlay particles being less distance `from the arc than the length `0f the molten puddle, the Width of the pile being in excess of that which can be completely melted by a linearly moving electrode without substantial penetration of the base, and

oscillating the electrode transversely of the pile while melting and moving the electrode along the length of the pile at a speed corresponding to the linearly moving electrode.

14. The method of claim 13 where the :sides of the pile contain more weldable overlay particles than the center thereof.

15. The method yof claim 14 where the surface has an exposed area from about 11/2 to about 4 times that of a substantially flat surface.

References Cited by the Examiner UNITED STATES PATENTS 2,841,687 7/1958 Richter 219-76 2,931,886 4/1960 Nunnelee et al. 219-76 3,019,327 1/1962 Engel 219-76 3,076,888 2/1963 Arnoldy 219-73 3,118,047 1/1964 Johnson 219-76 3,139,510 6/1964 Marion 219-76 RICHARD M. WOOD, Primary Examiner. JOSEPH V. TRUHE, Examiner.

Claims

1. A METHOD OF PRODUCING A WELD OVERLAY ON THE SURFACE OF A BASE COMPRISING, PLACING ON THE SURFACE OF THE BASE A PILE OF ELECTRICALLY CONDUCTIVE, WELDABLE OVERLAY PARTICLES IN A PREDETERMINED AMOUNT, THE WIDTH OF THE PILE BEING IN EXCESS OF THAT WHICH CAN BE COMPLETELY MELTED BY A LINEARLY MOVING ELECTRODE WITHOUT SUBSTANTIAL PENETRATION OF THE BASE, CREATING AN ARC FROM AN ELECTRODE TO THE UPPER PORTION OF THE PILE, AND