MXPA99001565A - Welding wire and method of making same - Google Patents

Abstract

A welding wire for use in electric arc welding and method of making same, wherein the wire has an effective outer diameter and comprises a length of solid metal formed into a series of distinct segments each having a selected volume and joined together by interconnecting bridging elements with the cross sectional area of the solid metal at said segments being greater than the cross sectional area of the solid metal at the bridging elements.

Description

WELDING WIRE AND METHOD TO DO THE SAME FIELD OF THE INVENTION The present invention relates to the technique of electric arc welding of the type in which a welding wire is directed towards a work piece and an electric current is passed through the welding wire towards the work piece to create a arc welding process, melting the end of the advancing wire and depositing the molten metal on the work piece, and more particularly to an improved welding wire for use in this arc welding process and the method for making this wire improved welder BACKGROUND OF THE INVENTION The electric arc welding of the type to which the present invention is directed, involves the use of a welding wire that is normally stored on a reel or roll, this wire is fed from the supply reel to a work piece through a tubular connector, in such a way that the current can be directed through the connector to the advancing welding wire and through the welding wire towards the work piece. The electric current heats the advance welding wire by heating l2R in such a way that the end of the welding wire is melted and deposited on the work piece by transfer through the arc or by other electrical and mechanical phenomena. Therefore, the advancing wire drives the welding current, which melts the wire for deposition of the molten metal from the end of the wire onto the workpiece. Over the years, there have been substantial improvements in the welding wire, which is usually a solid wire having a predetermined diameter and a lubricating surface, in this way, the wire can be moved at a controlled feed rate to melt and deposit the molten metal on the work piece. A protective gas can also be used around the advancing weld wire. A solid wire provides superior properties of arc welding; however it is commonly necessary to provide the welding wire with flux components and metal alloys to adjust the deposition of the molten metal to the desired metallurgical demands of the welding process. To achieve these additional features, it has become common practice to form the wire as a steel cover surrounding a central core consisting of fluxing ingredients and / or alloy powder. Consequently, there is a variety of core wires. By employing a core wire concept, the flux can be evenly distributed along the advancing weld wire. When the metal coating is produced from some standard steel, the core may include alloy powder. These metallic core metal electrodes use the powder metal in the core to adjust the deposited metal for a given welding process. There is a substantial advantage in the use of some welding processes when using wire with metallic core or with flux core. In fact, there are cases in which a combination of flux and alloy powder is used in the core of the wire. The advantages of these core wires or electrodes for the arc welding wire are somewhat counteracted by the fact that a solid metal wire typically produces superior arc welding. The metal is in the center of the arch and inside a cover that surrounds the arch, as in a wire with a flux or metal core. Both the solid metal wire and the metal core wire have a substantially constant wire length resistance, said resistance controls the arc welding process, especially in constant voltage arc welding processes. In some arc welding processes, it is desirable to have an increased length strength to optimize the welding process, but such modification affects the amount of the metal that is deposited. The solid metal wire and the metallic core wire meet the demands of the electric arc welding industry; however, they have the disadvantages caused by the restrictions of their physical characteristics, which in some cases do not allow the optimal electrical characteristics of the welding process.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a solder wire of solid metal, which has distinct quantized segments that facilitate superior drip transfer. Each of the segments has essentially the same volume. It has been found that the use of a solid wire for welding with different quantized segments, by bridge elements, works well with conventional sources of constant voltage welding. The current or the heating is controlled by an effective resistance or a resistance by length, whose resistance is increased by the use of interconnections of smaller bridge elements interconnecting between the longer segments. This type of solid wire has the advantage that it is easily made by simply processing the existing solid MIG wire, so as to produce a series of spaced indentations creating quantized segments between adjacent indentations. Such indentations can be made in the manufacturing facilities that make the solid wire, or in a device adjacent to the wire feeder in the welding station, which is almost always a robotic welding station. By employing the separated quantized segments in a solid welder wire, pulse arc welding can be coordinated in such a way that the pulse frequency and the wire feed speed provide a quantized segment at the time of each current pulse. This coordination stabilizes the transfer in pulse mode in such a way that only one drop separates with each pulse of current to optimize the characteristics of the welding in the forms that are well known within the welding technique. The electrode is heated by the passage of a current through the wire. The resistance of the wire has a direct effect on heating. Therefore, the effective resistance or resistance per length is increased by using smaller areas between the quantized segments, and the current decreases when a constant voltage is applied to the welding process. This resistance adjustment controls the heating of the advancing weld wire in a manner determined by the area and length of the bridge elements created by the indentations, defining the quantized elements spaced apart. In using the present invention, the resistance per wire length is higher than with a solid wire with the same external diameter. This is an advantage at high deposition rates because the heat input to the work piece can be reduced per unit weight of wire to extend the stable range of the process to constant voltage. By reducing the cross-sectional area of the metal in the bridge elements between the quantized segments, the resistance per length can be modified to suit the needs. The shape of the indentations created by the bridging elements between the quantized segments of the solid wire electrode may be in the form of circular grooves or other configurations that reduce the area and, therefore, increase the strength of the solid wire between the quantized segments. . If the bridge elements are in the form of circular grooves, the solid metal wire can be provided with fluxing, filling or alloying agents, in such a way that the agents are carried by the grooves without affecting the external diameter of the wire. metal. The electrical contact is maintained in the external portions of the quantized segments.

By adjusting the relative length of the quantized segments and the length of the slots forming the connecting elements, the desired amount of flux or alloying agents can be provided, by length of solid metal, advancing wire. This solid wire has the advantages of standard solid wire with the additional advantages of a wire with flux or metallic core. Another aspect of this invention includes the use of a metallic coating around the metal electrode to protect the fluxing agents, filling and alloying within the space created by the indentations, which form the bridge elements. This coating can be steel or copper to increase the electrical conduction, from the electrical contact in the welding equipment to the solid metal welding wire, advance. In this way moisture contamination and physical damage to flux, filler or alloying agents are inhibited. The coating or cover can be mechanically wrapped around the wire having the segments quantified spaced, from a standard spiral wrapping technique. The coating or cover can be placed around the wire and be stretched or rolled with the wire, using techniques similar to those employed in conventional core wire fabrication techniques. The coating or cover may also be provided by a technique of electroplating or by plasma spraying, while the covering or coating around the quantized segments is electrically conductive. Indeed, this coating or cover can be placed around the quantized segments forming the solid metal soldering wire without the use of fillers simply to increase the electrical characteristics or appearance of the advance metal wire stored on a reel for use in an automatic or semiautomatic electric arc welding process. According to the present invention, there is provided a welding wire for use in electric arc welding, wherein the welding wire has an effective outer diameter and comprises a length of the solid metal formed in a series of distinct segments, each having a selected volume and joined together by interconnecting the bridge elements with the cross-sectional area of the solid metal in these segments is greater than the cross-sectional area of the solid metal in the bridge elements. In this way, the solid metal soldering wire has different quantized segments. By controlling the contour of the connecting bridge elements, the resistance can be changed by length of welding wire, to control the welding process, so that less amount of current will be required to deposit a given amount of molten metal. In accordance with another aspect of the present invention, the bridge elements are formed by indentations, such as circular grooves, whose indentations can be filled with fluxing agent, metallic powder of alloys or other constituents to control the metallurgical and melting characteristics of the metallic wire. while maintaining the advantages of solid metal arc welding wire. According to another aspect of the present invention, the different, quantized metal segments have a maximum cross-sectional area that essentially defines the effective external diameter of the solid-metal soldering wire, while the maximum cross-sectional area of the bridging elements is considerably smaller than the maximum cross-sectional area of the quantized segments. According to yet another additional aspect of the present invention, there is provided a method for producing a solid welder wire for electric arc welding, which method comprises the steps of transporting a solid metal welder wire along a given path and It forms a series of indentations in the wire in equally separated positions, to define a series of different metallic segments, each having a selected volume. These quantified metal segments are joined together by bridge elements determined by the shape of the separation indentations. In practice, the indentations are circular grooves between the quantized metal segments of the solid welder wire. According to a still further aspect of the invention, this method includes the step of depositing the granular flux inside the indentations or depositing powdered alloy metal inside the indentations. In this way, the indentations can control the uniform distribution of the alloying agents and / or fluxing agents along the length of the solid welder wire, without requiring the use of a core wire concept. The method also contemplates the implementation of a further aspect of the invention in which a metal cover made of steel or other conductive material is placed around the solid metal soldering wire. By employing this invention, the series of the different quantized metal segments, which are joined together by the interconnection of the bridge elements, can have the effective resistance of the solid metal soldering wire, controlling in a precise manner when adjusting the ratio of the segments and the bridge elements. According to another aspect of the present invention, there is provided a method for controlling the resistance by length of a solid metal soldering wire, used by the arc welding process, which includes the steps of providing a solid metal soldering wire. , forming a series of indentations in the wire at separate sites, whereby the resistance for length in the indentations is greater than the resistance per length of the wire between the indentations, and controlling the size of the indentations to control the total resistance per length of the wire. This method is further modified by including the step of controlling the spaces between the indentations to provide quantized segments of generally equal metal volume.

The primary object of the present invention is to provide a solid metal soldering wire, said wire having a series of different, quantized segments joined together by the bridge elements. Another object of the present invention is to provide a solid metal solder wire, as defined above, whose solid metal wire can be produced from a standard MIG wire from manufacturing facilities or adjacent to wire feeder devices in the welding area. Still another object of the present invention is to provide a solid metal solder wire, as defined above, whose wire has improved arc stability and controlled heat input. The wire can greatly facilitate arc pulse welding in a welding process with constant voltage. Still another object of the present invention is to provide a solid metal solder wire, as defined above, whose wire can be produced to have a controlled length resistance greater than the length resistance of a metal wire of the same diameter. A further object of the present invention is to provide a solder wire of solid metal, as defined above, whose wire can be produced to control the resistance of the advancing lead welder wire per unit volume of the wire directed towards the workpiece. . Another object of the present invention is to provide a solder wire of solid metal, whose wire has a greater length strength than a solid wire of the same diameter. This objective is an advantage in the high deposition rate due to a decreased heat input to the work piece per unit wire length, which prolongs the stable range of a process at constant voltage. Still a further object of the present invention is to provide a solid metal solder wire, as defined above, whose soldering wire may have resistance per unit of controlled length or controlled resistance of the projection, only by using a series of indentations that define the different quantized segments of the wire. Another object of the present invention is to provide a solder wire of solid metal, as defined above, whose welding wire can be coordinated with the pulse welding process, in such a way that a quantized segment of the wire is provided to the arc of the welding process simultaneously with each pulse of current. A further object of the present invention is to provide a solder wire of solid metal, as defined above, whose welding wire can be provided with fluxing, filler and / or alloying agents, which may be contained in the wire so that the solid metal characteristics of the welder wire are maintained. In addition, the wire of the present invention can be provided with an external metal cover to maintain the fluxing, filler and / or alloying agents, and / or increase the conductivity of the advancing metal welding wire during the welding process. Another primary object of the present invention is the provision of a method for producing a welding wire for electric arc welding, said method forms a series of indentations in the wire to quantify the segments of the wire such that the wire can accept fluxing agents, of filler and / or alloys, and may have a resistance by length of controlled wire. Another object of the present invention is to provide a method as defined above, which can employ a standard MIG welding wire and be developed at a relatively low cost. These and other objects and advantages will become apparent from the following description taken together with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS FIGURE 1 is a side elevation view showing a solid metal soldering wire constructed in accordance with the present invention; FIGURE 2 is a cross-sectional area taken generally along line 2-2 or FIGURE 1; FIGURE 3 is an enlarged partial cross-sectional view, illustrating a quantized segment of the wire shown in FIGURES 1 and 2 with the indentations forming the bridge elements filled with a fluxing agent; FIGURE 4 is a similar view of FIGURE 3 with an external metal cover on the metal welding wire; FIGURE 4A is a figure similar to FIGURE 4 with the indentations filled with powdered alloy metal; FIGURE 4B is a view similar to FIGURE 4 with indentations filled with a fluxing agent; FIGURE 5 is a schematic side elevational view, illustrating a method for forming the quantized segments spaced in the solid metal solder wire, by using two rotating forming wheels; FIGURE 5A is an enlarged cross-sectional view taken generally along the line 5A-5A of FIGURE 5 in an indentation forming the bridge element; FIGURE 5B is an enlarged cross-sectional area, taken generally along line 5A-5A in a quantized segment of the wire; FIGURE 5C is a partial, amplified cross-sectional area of a forming wheel used in the formation of the indentations to define the quantized segments spaced in the metal weld wire; FIGURE 5D is a side elevational view in the partial cross section, showing the wire produced with a rotating forming wheel, as shown in Figure 5; and, FIGURE 6 is a composite view, showing the coordination between the pulses of the current in a pulse arc welding process and the mechanical aspects of the welding process, explaining the relationship between the pulses and the quantized segments of a wire welder, constructed in accordance with the present invention.

PREFERRED MODALITY OF THE INVENTION Referring now to the drawings, in which the images are for the purpose of illustrating a preferred embodiment of the present invention and not for the purpose of limiting the same, FIGS. 1 and 2 show a welding wire W constructed in accordance with the present invention. . This wire has a series of different quantized segments Q, separated by bridge elements B or connectors. These bridge elements are formed by a series of indentations 10 axially spaced inward from the cylindrical surface 12 of the welding wire W. The quantized segments Q can take a variety of forms, from the cylindrical to the spherical, and the connecting elements B also they may have a variety of shapes determined by the indentations 10 or other modifications similar to grooves extending inward from the surface 12. According to the invention, the quantized segments Q have a maximum diameter corresponding to the diameter a of the wire W. The maximum diameter of the segments determines the cylindrical surface 12 of the wire W. The connecting elements B have a diameter b. As illustrated in FIGURE 2, the cross-sectional area A1 of the segments Q is substantially greater than the cross-sectional area A2 of the elements B. Therefore, the resistance per wire length W is increased by the indentations 10. forming the bridge elements B. The relationship between the length c of the segment Q and the length d of the bridge element B determines the change or modification, in the resistance by length of wire W over the resistance by length of standard wire that has the diameter a. In this way, the indentations 10 have two general functions, the indentations separate the wire W in a series of quantized segments Q, each having essentially the same volume of metal. These indentations also increase the resistance through the wire W in such a way that the effective resistance per wire length W is controlled by the contour, size and configuration of the indentations 10. Therefore, the indentations 10 are used to control the resistance of the wire W, while the quantized segments Q provide a controlled transfer of molten metal droplet from the W wire during the arc welding process. As can be seen, a variety of dimensions can be provided for the Q segments and the indentations 10 to have precise control of the strength and welding characteristics of the solid wire W. However, the W wire still functions as a wire solid for welding The quantification of the segments in the solid welder wire and the control of the resistance through the wire is unique and forms the advantages of the invention, as discussed previously. In the preferred embodiment shown in FIGURES 1 and 2, the indentations are in the form of generally circular grooves, having a diameter b and a length d. By employing this or any other similar construction of indentations, it is possible to load the solid soldering wire W with the fluxing, filler and / or alloying agents. As shown in FIGURE 3, the grooves or indentations 10 are filled with a fluxing agent 20, which is generally granular in nature and formed into a paste. The paste is easily deposited in the grooves 10 and remains in the indentations or grooves 10. In this way, the amount of flow that is directed towards the arc in the welding process is controlled by the size and axial separation of the grooves or indentations. 10. The wire still has the characteristics of a solid metal wire, these characteristics produce arc stability, while still retaining the ability to carry a flux of controlled amounts to the arc during the welding process. In the past, the use of fluxes involved a welder wire with the flux core, whose wire did not have the beneficial properties of a solid wire. There are bar electrodes that have flux agents that line the outside of the electrodes. Said outer cover may not be used by the welding wire of the type to which the present invention is directed.

In some cases, it is advisable to protect the indentations 10 with an appropriate metallic coating 30, as illustrated in FIGURE 4. This coating can be a steel coating such as that used in flux cored wires. Additionally, this may be a copper coating to increase electrical contact with the W wire in the welding equipment. By using the coating 30, the indentations or slots 10 are closer together, so that they can retain the alloy powder 32, as shown in FIGURE 4A, or granular fluxing agents 34 as shown in FIGURE 4B. The disclosure of FIGURES 3, 4, 4A and 4B show that a variety of structures can be used for any of the closing indentations 10 and / or the load indentations 10 with several additional constituents, without compromising the characteristics of the solid wire. of the wire W or the resistance control characteristics obtained with the use of the separate indentations 10. As shown in FIGURE 3, the electrical contact with the surface 12 and the ratio of diameter a to diameter b the length ac the length d can be adjusted to control the proportion of the amount of materials 20, 32 and 34 with respect to the volume of the wire W. The jacket or coating 30 prevents moisture and other contaminations from entering the indentations 10 and keeps agents 32 and 34 instead. In practice, when the coating 30 is used, it is wrapped around the quantified wire as a metallic paper wrapper, employing a spiral wrapping technique. The indentations 10 can have a variety of forms and can be propitiated by a variety of procedures. Actually the indentations can easily be formed by joining together the quantized elements Q in a continuous wire W. Therefore, the "indentations" indicate the existence of a reduced volume inwards of the diameter 12, but not necessarily the procedure to realize it. reduction in the volume and the increase of the resistance in the elements B. In FIGURES 5, 5A, 5B, 5C and 5D schematically illustrates a procedure for the realization of the indentations 10, wherein the forming wheels 50, 52 are located adjacent to the extruder outlet of the wire 60 that produces a standard MIG wire C. The wheels 50, 52 have a series of teeth or vanes 70, 72 circumferentially spaced apart, converging on the joint 74, as shown in FIG. 5A for perforating the wire C in axially spaced positions to create the grooves or indentations 10. The raised areas 80, 82 are located on the rollers 50, 52 respectively. to generate the quantized segments different Q to produce a wire W, as shown in FIGURE 5B. As shown in FIGURE 5D the outer surface 12 of the wire may have a certain disuniformity created by piercing the metal forming the wire C to create the spaced quantized Q quantized segments. This perforation action is less and yet produces a generally cylindrical external surface, said surface can be used to direct the electric current towards the wire W during the welding process. The forming wheels 50, 52 can be located adjacent to the welding operation in front of the wire feeder to drive the welding wire W towards the welding area. In this way an operator can elaborate on design the size of the segments Q and the configuration of the indentations 10 with respect to the actual welding process that is carried out. A different group of wheels 50, 52 can be provided for various welding operations. A standard MG wire C can be supplied to the welding locations and the quantized segments Q in the wire will be formed in this site. This is an advantage of the present invention and allows the production on design of a solid welder wire, having Q quantized segments separated by bridge elements B. Other arrangements can be provided to create the indentations 10, such as laser cutters, mills, saws, etc. An advantage of a solid welder wire constructed in accordance with the present invention is that it can be coordinated with a pulse welding process, as schematically illustrated in FIGURE 6 where a series of current pulses 100 from a voltage power source constant has a time spacing from t1 to t2. The pulse frequency of the pulse current 100 is a known value, such as X pulses per minute. The lower portion of FIGURE 6 illustrates schematically the welding process, in which the wire W is passed through a sleeve contact 110 in the direction of a workpiece 112 such that the wire W is fused in the arc D by pulses from a power source connected to the negative terminal 120 and positive 122. As the pulses 100 are directed through the arc D, the wire W moves at a wire feed speed providing a quantized segment Q at the same time of a pulse current 100. The wire feed speed is coordinated with the frequency of the pulse current in such a way that a quantified amount of metal is provided for each pulse to melt during the welding process. This ability to coordinate specific amounts of metal for each pulse stream is an advantage of the present invention. As previously discussed, there are other advantages where the novel concept of quantized segments joined together to form a solid metal solder wire can produce controlled resistance and superior droplet transfer.

Claims (60)

1. A welder wire for use in electric arc welding, said wire having an effective outer diameter and comprising a length of solid metal formed in series of distinct segments, each having a selected volume and joined together by interconnecting the bridge elements with the area of cross section of said solid metal being greater than the cross-sectional area of said solid metal in the bridge elements.

A welding wire according to claim 1, wherein said segments are generally cylindrical with an external diameter corresponding to the effective external diameter of said wire.

3. A soldering wire according to claim 2, wherein said connecting bridge elements have a smaller diameter than the effective diameter to define circular grooves between these segments.

A soldering wire according to claim 1, wherein said connecting bridge elements have a smaller diameter than the effective diameter to define circular grooves between said segments.

5. A soldering wire according to claim 4, wherein said grooves contain granular flux.

6. A soldering wire according to claim 5, wherein said grooves contain metallic alloy powder.

7. A soldering wire according to claim 4, wherein said grooves contain metallic alloy powder.

8. A soldering wire according to claim 3, wherein said grooves contain granular flux.

9. A welder wire according to claim 8, wherein said grooves contain metallic alloy powder.

A welder wire according to claim 9, including an outer metallic coating surrounding said length of the solid metal.

11. A soldering wire according to claim 8, including an outer metallic coating surrounding the length of the solid metal.

12. A soldering wire according to claim 7, including an outer metallic coating surrounding said length of the solid metal.

13. A soldering wire according to claim 6, including an outer metallic coating surrounding said length of the solid metal.

14. A soldering wire according to claim 5, including an external metallic coating surrounding said length of the solid metal.

15. A soldering wire according to claim 4, including an outer metallic coating surrounding said length of the solid metal.

16. A soldering wire according to claim 3, including an outer metallic coating surrounding the length of the solid metal.

17. A soldering wire according to claim 2, including an outer metallic coating surrounding the length of the solid metal.

18. A soldering wire according to claim 1, including an outer metallic coating surrounding the length of the solid metal.

19. A welder wire according to claim 2, wherein said connecting bridge elements are generally cylindrical with a smaller diameter than said effective diameter to define the circular grooves between said segments.

20. A welder wire according to claim 1, wherein said connecting bridge elements are generally cylindrical with a smaller diameter than said effective diameter to define the circular grooves between said segments.

21. A soldering wire according to claim 20, wherein said grooves contain granular flux.

22. A welder wire according to claim 20, wherein said grooves contain metallic alloy powder.

23. A soldering wire according to claim 22, including an outer metallic coating surrounding the length of the solid metal.

24. A soldering wire according to claim 21, which includes an outer metallic coating surrounding the length of the solid metal.

25. A soldering wire according to claim 20, including an outer metallic coating surrounding the length of the solid metal.

26. A soldering wire according to claim 19, including an outer metallic coating surrounding the length of the solid metal.

27. A welder wire for use in electric arc welding, said wire formed of a solid metal with an effective outer diameter and comprising a series of distinct segments joined together by interconnecting bridge elements, the elements having a given volume and a maximum area of cross section generally determined by said effective outer diameter, and said bridge elements having a maximum cross-sectional area, wherein said maximum cross-sectional area of these segments is substantially greater than the maximum cross-sectional area of the bridge elements.

28. A welder wire according to claim 27, wherein said segments are generally cylindrical with an outer diameter corresponding to said effective outer diameter of the wire.

29. A welder wire according to claim 28, wherein the connecting bridge elements have a smaller diameter than the effective diameter to define the circular grooves between said segments.

30. A welder wire according to claim 27, wherein the connecting bridge elements have a smaller diameter than the effective diameter to define the circular grooves between said segments.

31. A soldering wire according to claim 28, wherein said connecting bridge elements are generally cylindrical with a smaller diameter than said effective diameter to define circular grooves between said segments.

32. A welder wire according to claim 27, wherein said connecting bridge elements are generally cylindrical with a smaller diameter than said effective diameter to define circular grooves between said segments.

33. A welder wire according to claim 27, wherein said interconnecting bridge elements are formed by a series of indentations in said solid metal between these segments.

34. A welder wire according to claim 1, wherein said interconnecting bridge elements are formed by a series of indentations in said solid metal between these segments.

35. A method for producing a welder wire for electric arc welding, said method comprising the steps of: (a) transporting a solder wire of solid metal along a given path, and (b) forming a series of indentations in said wire in equally spaced locations to define a series of distinct metal segments, each having a selected volume.

36. A method for producing a welder wire according to claim 35, wherein said indentations are circular grooves between said metal segments of the same volume.

37. A method for producing a welder wire according to claim 36, which includes the additional step of depositing granular flux within said indentations.

38. A method for producing a welder wire according to claim 35, which includes the additional step of depositing granular flux within said indentations.

39. A method for producing a welder wire according to claim 36, which includes the additional step of depositing powdered alloy metal within said indentations.

40. A method for producing a welder wire according to claim 39, which includes the additional step of depositing powdered alloy metal within said indentations.

41. A method for producing a welder wire according to claim 40, which includes the additional step of placing a metal coating around the wire.

42. A method for producing a welder wire according to claim 39, which includes the additional step of placing a metallic coating around the wire.

43. A method for producing a welder wire according to claim 38, including the additional step of placing a metal coating around the wire.

44. A method for producing a welder wire according to claim 37, which includes the additional step of placing a metal coating around the wire.

45. A method for producing a welder wire according to claim 36, which includes the additional step of placing a metal coating around the wire.

46. A method for producing a welder wire according to claim 35, which includes the additional step of placing a metallic coating around the wire.

47. A welder wire for use in electric arc welding, said wire having an effective outer diameter and comprising a length of solid metal formed in a series of distinct segments joined together by interconnecting the bridge elements with a length resistance in said segments that it is substantially less than the length resistance in the elements.

48. A solder wire according to claim 47, wherein said segments are generally cylindrical with an external diameter corresponding to the effective external diameter of the wire.

49. A soldering wire according to claim 47, wherein said connecting bridge elements are generally cylindrical with a smaller diameter than the effective diameter to define circular grooves between these segments.

50. A soldering wire according to claim 49, wherein said grooves contain granular flux.

51. A soldering wire according to claim 49, wherein said grooves contain metallic alloy powder.

52. A soldering wire according to claim 47, including an external metallic coating surrounding the length of said solid metal.

53. A welder wire according to claim 47, wherein said interconnecting bridge elements are formed by a series of indentations in said solid metal between the segments.

54. A solder wire according to claim 47, wherein each of said segments has a given volume.

55. A method for arc welding a workpiece with a wire having a series of distinct segments of generally equal volume, joined together by interconnecting bridge elements generally smaller than said segments, wherein said segments are spaced along this wire at a selected distance, said welding comprises the steps of: (a) moving the wire towards the work piece at a controlled feed rate, supplying a given number of segments per minute; (b) applying a pulse welding current between said wire and the workpiece, with a pulse velocity of a given number of pulses per minute; Y, (c) controlling the pulse rate and the feed rate such that the given number of segments generally equals the given number of pulses.

56. A method for arc welding according to claim 55, wherein said pulse welding current is provided by a constant voltage during each of said pulses.

57. A method for controlling the resistance per length of solder wire of solid metal used for electric arc welding, which includes the steps of: (a) providing a solid metal soldering wire; (b) forming a series of indentations in said wire at separate sites, whereby the resistance per length of said wire in the indentations is greater than the resistance per length of said wire between these indentations; and (c) controlling the size of said indentations to control the resistance by length of said wire.

58. A method for controlling the resistance by solder wire length of solid metal, according to claim 57, which includes the additional step of selecting said spaces between the indentations to provide the quantized segments of generally equal volume between said indentations.

59. A method for controlling the resistance by solder wire length of solid metal, according to claim 58, wherein said indentations are formed by the deformation of said wire.

60. A method for controlling the resistance by solder wire length of solid metal, according to claim 57, wherein said indentations are formed by the deformation of said wire.