System and method for preheating a welding wire

Abstract

A contact tip assembly having a preheated tip includes a welding-type power source configured to supply a welding-type current to a welding-type circuit including a welding-type electrode and a first contact tip of a torch. The assembly further includes an electrode preheating circuit and a voltage sensing circuit, the electrode preheating circuit being configured to supply a preheating current through a portion of the welding-type electrode via a second contact tip of the torch, the voltage sensing circuit monitoring a voltage drop across the two contact tips, and the electrode preheating circuit adjusting at least one of a first current or the preheating current based on the voltage drop.

Description

[0001] This application is a divisional application of a patent application for invention with an international filing date of April 27, 2018, an international application number of PCT / US2018 / 029770, a national application number of 201880031621.2, and an invention title of "Systems and Methods for Preheating a Welding Wire".

[0002] Related Applications

[0003] This international application claims the priority of U.S. Patent Application Serial No. 15 / 596,387, entitled "Methods and Apparatus for Detecting Leakage Current", filed on May 16, 2017. The entire content of U.S. Patent Application Serial No. 15 / 596,387 is incorporated herein by reference. Background Art

[0004] Welding is a process that has historically been a cost-effective joining method. Welding is simply, by its nature, a way to join two parent materials. For various purposes, a wide variety of welding systems and welding control schemes have been implemented. In continuous welding operations, metal inert gas (MIG) welding and submerged arc welding (SAW) techniques allow for the formation of continuous welds by feeding a wire protected by an inert gas from a torch. Such wire feeding systems can be used in other welding systems, such as tungsten inert gas (TIG) welding. Electrical power is applied to the wire, and the circuit is completed through the workpiece to maintain the welding arc, which melts the electrode wire and the workpiece to form the desired weld.

[0005] While these welding techniques are very effective in many applications, they may experience different initial welding performance based on whether the welding starts with a "cold" or "hot" electrode. Generally, a cold electrode start can be considered a start where the electrode tip and adjacent metal are at or relatively close to ambient temperature. Conversely, a hot electrode start is typically those starts where the electrode tip and adjacent metal are much warmer but below the melting point of the electrode wire. In some applications, it is believed that the initiation of the welding arc and welding is facilitated when the electrode is hot. However, the prior art does not provide a scheme designed to ensure heating of the electrode before starting a welding operation.

[0006] Certain improvements have been made to the process of preheating the electrode. For example, U.S. Patent Publication No. 2014 / 0021183A1 to Peters describes a torch having a contact tip with electrically isolated upper and lower portions, each portion providing a part of the concentrated welding current waveform. Similarly, U.S. Patent Nos. 4,447,703, 4,547,654, and 4,667,083 and PCT Publication No. WO / 2005 / 030422 describe various preheating techniques using dual contact tips. Nevertheless, there is still a need for improved welding strategies that allow welding to be initiated with a heated electrode wire in order to improve welding performance. Summary of the Invention

[0007] The present disclosure generally relates to a wire preheating system, method, and apparatus for use with a torch, and more particularly, the present invention relates to a torch that enables a continuously fed electrode wire to be preheated for various forms of electric welding. Brief Description of the Drawings

[0008] The features of the present invention can be best understood from a detailed description of the invention and its preferred embodiments selected for purposes of illustration and shown in the accompanying drawings, in which:

[0009] Figure 1 An example robotic welding system is shown.

[0010] Figure 2A A side view of an example robotic gooseneck torch having an air-cooled preheater section is shown.

[0011] Figure 2B A cross-sectional side view of an example robotic gooseneck torch having an air-cooled preheater section is shown.

[0012] Figure 2C A perspective view of an example robotic gooseneck torch having a liquid-cooled welding cable is shown.

[0013] Figure 2D A cross-sectional perspective view of an example robotic gooseneck torch having a liquid-cooled welding cable is shown.

[0014] Figure 3 A functional diagram of an exemplary contact tip assembly is shown.

[0015] Figure 4A 、 4B and 4C show example preheated torch wire configurations.

[0016] Figure 5 A functional diagram of another exemplary contact tip assembly is shown, in which a power supply provides welding power to the electrode wire.

[0017] Figure 6 A functional diagram of another example contact tip assembly is shown, where the electrical connection between the preheat power supply and the contact tip is reversed with respect to the connection in Figure 5 .

[0018] Figure 7 A functional diagram of another example contact tip assembly is shown, where the power supply provides welding power to the electrode wire.

[0019] Figure 8 A functional diagram of another example contact tip assembly is shown, where a single power supply provides both preheat power and welding power to the electrode via the first contact tip and / or the second contact tip.

[0020] Figure 9 An example welding assembly is shown that includes voltage sensing leads to measure the voltage drop across two contact tips for preheating the electrode wire.

[0021] Figure 10 An example welding assembly including an enthalpy measurement circuit is shown.

[0022] Figure 11 An example implementation is shown that provides a resistance preheated wire to the workpiece and provides a separate arc source (e.g., a tungsten electrode) to melt the wire.

[0023] Figure 12 An example implementation is shown that provides a resistance preheated wire to the workpiece and provides a separate arc source (e.g., one or more laser sources) to melt the wire.

[0024] Figure 13 An example user interface device is shown that can be used to implement the user interface of a welding device.

[0025] Figure 14A , 14B and 14C show example average heat inputs for different preheat levels.

[0026] Figure 15 An example welding assembly is shown that uses a welding control circuit including a user interface and implementing a preheat control loop.

[0027] Figure 16a is Figure 15 a block diagram of an example implementation of the preheat control loop of

[0028] Figure 16b is Figure 15 a block diagram of another example implementation of the preheat control loop of

[0029] Figure 17 is Figure 3 , 5Block diagram of an example implementation of a power supply for 6, 7, 8, 9, 10, and / or 15.

[0030] Figure 18 Is a flowchart representing example machine-readable instructions that can be executed by an electrode preheat control circuit and / or a welding control circuit to control the preheating of a welding electrode based on user input to a user interface.

[0031] The figures are not drawn to scale. Where appropriate, the same or similar reference numerals are used in the figures to denote similar or identical elements. Detailed Description

[0032] To facilitate an understanding of the principles of the claimed technology and to present its currently understood best mode of operation, reference will now be made to the embodiments illustrated in the figures, and specific language will be used to describe these embodiments. However, it should be understood that no limitation of the scope of the claimed technology is thereby intended, such changes and further modifications in the illustrated devices and such further applications of the principles of the claimed technology as illustrated are considered to be ordinarily contemplated by those skilled in the art to which the claimed technology pertains.

[0033] As used herein, the word "exemplary" means "serving as an example, instance, or illustration." The embodiments described herein are not limiting, but merely exemplary. It should be understood that the described embodiments are not necessarily to be construed as preferred or advantageous over other embodiments. Additionally, the term "embodiment" does not require that all embodiments of the present disclosure include the discussed features, advantages, or modes of operation.

[0034] As used herein, a wire-fed welding type system refers to a system capable of performing welding (e.g., gas metal arc welding (GMAW), gas tungsten arc welding (GTAW), etc.), brazing, cladding, hardfacing, and / or other processes, where the filler metal is provided by a wire fed to a working location (e.g., an arc or a weld pool).

[0035] As used herein, a welding type power supply refers to any device that can supply welding, cladding, plasma cutting, induction heating, laser (including laser welding and laser cladding), carbon arc cutting or gouging, and / or resistance preheating when power is applied to it, including but not limited to transformer-rectifiers, inverters, converters, resonant power supplies, quasi-resonant power supplies, switched-mode power supplies, etc., and associated control circuitry and other auxiliary circuitry.

[0036] As used herein, preheating refers to heating the electrode wire before the welding arc and / or the electrode wire deposition in the travel path.

[0037] For convenience, the term "power" is used throughout the specification, but also includes related metrics such as energy, current, voltage, and enthalpy. For example, controlling "power" may include controlling voltage, current, energy, and / or enthalpy, and / or control based on "power" may include control based on voltage, current, energy, and / or enthalpy. This electrical power measured in watts as the product of voltage and current (e.g., V*I power) is referred to herein as "wattage".

[0038] Some of the disclosed examples describe current conducting "from" and / or "to" locations in a circuit and / or power supply. Similarly, some of the disclosed examples describe "providing" current via one or more paths, which may include one or more conductive or partially conductive elements. The terms "from", "to", and "providing" used to describe current conduction do not require the direction or polarity of the current. Instead, for a given circuit, even if an exemplary current polarity or direction is provided or shown, the currents may conduct in either direction or have either polarity.

[0039] Example consumable electrode feed welding-type systems of the present disclosure include a welding-type power supply, an electrode preheating circuit, and an electrode preheating control circuit. The welding-type power supply provides welding-type power to a welding-type circuit, where the welding-type circuit includes a welding-type electrode and a first contact end of a torch. The electrode preheating circuit provides preheating power through a first portion of the welding-type electrode via a second contact end of the torch. The electrode preheating control circuit is configured to control the preheating power based on a user input specifying the preheating power.

[0040] Some example systems also include a user interface to receive a selection of preheating power, where the electrode preheating control circuit controls the preheating power and the welding-type power based on the selection. In some such examples, the selection includes at least one of preheating current, preheating voltage, preheating power, impedance, or preheating enthalpy. In some examples, the electrode preheating control circuit uses at least one of a preheating upper limit or a preheating lower limit to limit the selection of preheating power.

[0041] In some example systems, the user interface displays values representing preheating power and / or welding-type power and updates the values in response to a selection of a preheating power level. In some such examples, the user interface displays the values with reference to an allowed selection range of the values.

[0042] In some example systems, the user interface displays values representing at least one of preheating voltage, preheating current, preheating power, total energy of the welding-type power, or heat input efficiency, and updates the values in response to a selection of preheating power. In some examples, the user interface receives a selection of a welding penetration amount, where the electrode preheating control circuit controls the preheating power and the welding-type power based on the selection.

[0043] In some such examples, the electrode preheat control circuit reduces the preheat power and increases the weld-type power in response to an increase in the selected weld penetration depth. In some examples, the electrode preheat control circuit increases the preheat power and reduces the weld-type power in response to a decrease in the selected weld penetration depth. Some examples also include a penetration depth sensor configured to detect the weld penetration depth, wherein the electrode preheat control circuit controls the preheat power and the weld-type power to maintain the amount of weld penetration depth within a threshold range.

[0044] In some examples, the electrode preheat control circuit uses at least one of a penetration depth upper limit or a penetration depth lower limit to limit the selection of the amount of weld penetration depth. In some example systems, the electrode preheat control circuit controls the preheat power based on at least one of a target total heat input for welding, a travel speed, a target bead width, or a target penetration depth.

[0045] In some examples, the electrode preheat control circuit uses a first control loop to control the preheat voltage of the preheat power, and the first control loop takes a user input as an input to the control loop. In some examples, at least one of the electrode preheat control circuit or the weld control circuit controls the weld-type power based on the preheat power. In some examples, the user input specifies the preheat power as at least one of the following: a ratio based on at least one of the preheat power, the voltage of the preheat power, the current of the preheat power, or the impedance of a first portion of the weld-type electrode, and a ratio based on at least one of the weld-type power, the voltage of the weld-type power, the current of the weld-type power, or the arc impedance.

[0046] Some example systems also include a display device to display the balance between the preheat power and the weld-type power based on the user input, display the total heat input of the preheat power and the weld-type power, and update the display of the balance and the total heat input in response to a change in the user input. In some examples, the electrode preheat circuit is configured to provide the preheat power via a second contact tip and a first contact tip. In some examples, the electrode preheat circuit is configured to provide the preheat power via a second contact tip and a third contact tip.

[0047] Example consumable electrode feed weld-type systems of the present disclosure include a weld-type power source, an electrode preheat circuit, and an electrode preheat control circuit. The weld-type power source provides weld-type power to a weld-type circuit based on a first control loop, wherein the weld-type circuit includes a weld-type electrode and a first contact tip of a torch. The electrode preheat circuit provides preheat power through a first portion of the weld-type electrode via a second contact tip of the torch. The electrode preheat control circuit controls the preheat power based on a second control loop having a user input that specifies at least one of a target heat input, a target preheat power level, a target ratio between the preheat power and the weld-type power, or a target arc penetration depth, and the first control loop responds to the preheat power.

[0048] Example methods of the present disclosure include determining a target preheat power level via a control circuit based on a user input that specifies at least one of a target heat input, a target preheat power level, a target ratio between preheat power and weld-type power, or a target weld penetration depth. The method also includes controlling, via the control circuit based on the user input, the delivery of preheat power through a first portion of a weld-type electrode via first and second contact tips of a torch. The method also includes controlling, via the control circuit based on the preheat power, the delivery of weld power to the weld-type electrode via the first contact tip. Example methods also include controlling, via the control circuit, a user interface device to display at least one of a voltage of the preheat power, a current of the preheat power, a heat input of the preheat power, a heat input of the weld-type power, or a total heat input of the preheat power and the weld power.

[0049] Reference Figure 1 , an example welding system 100 is shown, where a robot 102 is used to weld a workpiece 106 using a welding tool 108 (e.g., the shown bent neck (i.e., gooseneck design) torch (or, when under manual control, a hand-held torch)), and the power supplied to the torch is delivered by a welding rig 110 through a conduit 118 and returned through a ground conduit 120. The welding rig 110 may include, among other things, one or more power sources (each generally referred to herein as a "power supply"), a shielding gas source, a wire feeder, and other equipment, etc. Other equipment may include, for example, a water cooler, a fume extraction device, one or more controllers, sensors, a user interface, communication equipment (wired and / or wireless), etc.

[0050] Figure 1The welding system 100 can form a weld (e.g., at the weld joint 112) between two components in a welded piece by any known electric welding technique. Known electric welding techniques include, among others, shielded metal arc welding (SMAW), MIG, flux-cored arc welding (FCAW), TIG, laser welding, submerged arc welding (SAW), stud welding, friction stir welding, and resistance welding. MIG, TIG, hot wire cladding, hot wire TIG, hot wire brazing, multi-arc applications, and SAW welding techniques can also include, among others, automatic or semi-automatic external metal filler (e.g., via a wire feeder). In multi-arc applications (e.g., open arc or submerged arc), a preheater can utilize the arc between the wire and the molten pool to preheat the wire into the molten pool. Optionally, in any embodiment, the welding equipment 110 can be arc welding equipment having one or more power supplies and associated circuitry that provides direct current (DC), alternating current (AC), or a combination thereof to the electrode wire 114 of the welding tool (e.g., the welding tool 108). The welding tool 108 can be, for example, a TIG torch, a MIG torch, or a flux-cored torch (commonly referred to as a MIG "gun"). The electrode wire 114 can be a tubular-type electrode, a solid-type wire, a flux-cored wire, a seamless metal-cored wire, and / or any other type of electrode wire.

[0051] As described below, the welding tool 108 can employ a contact tip assembly 206 that heats the electrode wire 114 before forming the welding arc 320 using the electrode wire 114. Suitable types of electrode wire 114 include, for example, tubular wire, metal-cored wire, aluminum wire, solid gas metal arc welding (GMAW) wire, gas-shielded FCAW wire, SAW wire, self-shielded wire, etc. In one aspect, the electrode wire 114 can employ a combination of tubular wire and reverse polarity current, which increases metal transfer stability by changing the metal transfer from globular transfer to streaming spray. By preheating the tubular electrode wire 114 before the wire exits the first end and is fed into the arc (where material transfer occurs), the tubular electrode wire 114 behaves more like a solid wire because the material transfer is a more uniform spray or streaming spray. Additionally, the outgassing events and events that cause very fine spatter typically seen when welding with metal-cored wire are reduced. This configuration enables the tubular wire to function in a manner similar to a solid wire-type streaming spray. Another benefit of preheating is that wire flipping due to poor wire casting and helix control in wire manufacturing (which may be more significant in seam tubular wire than in solid wire) is reduced because undesirable wire twisting will be reduced in the preheating section.

[0052] As will be described with respect to Figures 2A to 2DAs discussed, the welding tool 108 can be a gooseneck torch, such as those used in robotic welding, but other shapes can also be considered, including almost any neck bend angle greater than zero, hand-held for low-hydrogen FCAW welding, hand-held for GMAW, straight-neck rigid automated torches, straight-neck SAW torches, etc. Figure 2A A side view of an example robotic gooseneck torch with an air-cooled preheater section is shown. Figure 2B A cross-sectional side view of an example robotic gooseneck torch with an air-cooled preheater section is shown. Figure 2C A perspective view of an example robotic gooseneck torch with a liquid-cooled welding cable is shown. Figure 2D A cross-sectional perspective view of an example robotic gooseneck torch with a liquid-cooled welding cable is shown, with the copper conductor partially shown. In some aspects, multiple ceramic guides or rollers can be used to provide a preheater with a bend therein, which can have the advantage of contacting the contact tip and allowing a unique form factor. In other aspects, the neck can be straight and the robotic mounting bracket has a bend.

[0053] However, the gooseneck torch design has many advantages. For example, the gooseneck torch design allows better access to the welding joint 112, as well as automation capabilities in heavy equipment applications. Compared to, for example, tandem torch designs, the gooseneck torch design also allows for thicker deposition welding in tighter spaces. Thus, in operation, the electrode wire 114 delivers welding current to the welding point (e.g., welding joint 112) on the workpiece 106 (e.g., weldment) to form a welding arc 320.

[0054] In the welding system 100, the robot 102, which is operatively coupled to the welding equipment 110 via the conduit 118 and the ground conduit 120, controls the position of the welding tool 108 and the operation of the electrode wire 114 (e.g., via a wire feeder) by manipulating the welding tool 108 and by sending, for example, a trigger signal to the welding equipment 110 to trigger the start and stop of the current flowing to the electrode wire 114 (whether preheat current and / or welding current). When the welding current is flowing, a welding arc 320 is generated between the electrode wire 114 and the workpiece 106, thereby ultimately producing a weldment. The conduit 118 and the electrode wire 114 thus convey a welding current and voltage sufficient to generate a welding arc 320 between the electrode wire 114 and the workpiece 106. At the welding point between the electrode wire 114 and the workpiece 106, the welding arc 320 locally melts the workpiece 106 and the electrode wire 114 provided to the welding joint 112, thereby forming the welding joint 112 when the metal cools.

[0055] In some aspects, instead of the robotic arm of the robot 102, a human operator may control the position and operation of the electrode wire 114. For example, the operator wears a welding headset and uses a hand-held torch to weld the workpiece 106, and the welding equipment 110 delivers power to the hand-held torch through the conduit 118. During operation, like the system 100 of Figure 1 , the electrode wire 114 delivers current to a welding point on the workpiece 106 (e.g., a weldment). However, the operator can control the position and operation of the electrode wire 114 by manipulating the hand-held torch and triggering the start and stop of the current, for example, through a trigger. The hand-held torch typically includes a handle, a trigger, a conductor tube, a nozzle at the distal end of the conductor tube, and a contact tip assembly 206 as disclosed herein. Applying pressure to the trigger (i.e., actuating the trigger) starts the welding process by sending a trigger signal to the welding equipment 110, thereby providing welding current and starting the wire feeder as needed (e.g., driving the electrode wire 114 forward to feed the electrode wire 114 and in reverse to retract the electrode wire 114). For example, commonly owned U.S. Patent No. 6,858,818 to Craig S. Knoener describes an example system and method for controlling a wire feeder of a welding-type system. The present disclosure can be implemented with a rotating arc and reciprocating wire feeding. In one example, the bottom end can be moved to rotate the preheated wire. In another example, the wire can be axially moved forward and backward by an upstream reverse wire feed motor before being preheated. Both the rotation and reverse wire feeding can have a positive impact on the melting rate and deposition of the wire. When combined, they can exacerbate the effect on the deposition rate.

[0056] Figure 2A A perspective view of an example robotic gooseneck torch 108 is shown. The illustrated gooseneck torch 108 generally includes a torch body 202, a gooseneck 204 extending from the front end of the torch body 202, and a contact tip assembly 206 at the distal end of the gooseneck 204 or through the radius of the gooseneck 204. The conduit 118 of the welding system 100 is operatively coupled to the rear end of the torch body 202, and the conduit 118 is further operatively coupled to the robot 102 and the welding equipment 110. The conduit 118 supplies current, shielding gas, and a consumable electrode (e.g., the electrode wire 114), among other things, to the torch body 202. The current, shielding gas, and consumable electrode travel through the torch body 202 to the gooseneck 204 and ultimately exit through an orifice at the distal end of the contact tip assembly 206, where a welding arc 320 is ultimately formed. In some aspects, the gooseneck torch 108 can be fluid-cooled, such as air-cooled and / or liquid-cooled (e.g., water-cooled). In one embodiment, a liquid cooling mechanism surrounds the preheated contact tip and transfers additional heat out from a preheater within the torch body.

[0057] For ease of maintenance, the gooseneck torch 108 can be configured with interchangeable components and consumables. For example, the gooseneck torch 108 can include quick-change add-ons and / or a second contact tip, which allows for the adaptation of existing water-cooled / air-cooled torches. For example, commonly-owned U.S. Patent Publication No. 2010 / 0012637 discloses a suitable gooseneck locking mechanism for a robotic torch having a torch body and a gooseneck that includes a connector receiver disposed in the torch body.

[0058] The enclosure for the power supply for preheating can take one of a variety of forms. In a preferred aspect, the preheat power supply can be integrated with the welding power supply, or within the same housing. Within the same enclosure, the preheat power supply can be a secondary power supply that is fed from the main power supply by its own independent transformer; however, the preheat power supply can also share the same primary winding and core of the transformer used for the welding current by being fed from a dedicated secondary winding. The integrated enclosure provides simplicity in terms of interconnection, installation, and service. Another embodiment is that the preheat power supply is separately enclosed in its own housing, which is beneficial for retrofitting into existing equipment and allows for "mix and match" flexibility when paired with other power supplies (such as those suitable for open arc welding and submerged arc welding). The separate enclosure also requires communication between the controller within the welding power supply and the preheat power supply. The communication can be provided through digital networking, or more specifically through an industrial serial bus, CAN bus, or Ethernet / IP. The separate enclosure can also result in the power output of the preheat power supply and the output of the welding power supply being combined, possibly in the wire feeder, or in a junction box before the torch, or in the torch itself.

[0059] In open arc welding, there are two derivative weldings: high deposition welding common in shipbuilding and heavy equipment manufacturing (usually groove, butt, and fillet joints, 15 - 40 ipm travel speed); and high speed welding common in automotive (usually lap joints, 70 - 120 ipm travel speed). In both cases, wire preheating improves deposition and / or travel speed. In open arc, solid wire or metal cored wire can be used with GMAW; or flux cored wire can be used with FCAW as the process. In submerged arc welding, solid wire or metal cored wire can be used. In both open arc and submerged arc, multiple wire and / or arc combinations are possible. For example, the lead wire is subjected to preheating and arc, but the trail wire is only subjected to preheating without being subjected to arc. Another example is that both the lead wire and the trail wire are subjected to preheating and arc. Yet another example is that there are 3 wires, where the first wire and the third wire are both subjected to preheating and arc, but the middle wire is only subjected to preheating without being subjected to arc. There are many possible arrangements. The third group of applications is to use another non - consumable heat source such as laser, plasma, or TIG for resistance preheating for welding, brazing, cladding, and hardfacing. The wire is preheated by resistance preheating and fed into a liquid molten pool melted by laser, plasma, or TIG.

[0060] In some examples, the second contact tip (e.g., farther from the arc) is spring - loaded, a general - purpose contact tip. The spring pressure in the second contact tip improves electrical contact regardless of electrical corrosion and / or mechanical wear on the contact tip. Traditional spring - loaded contact tips are relatively expensive and prone to damage due to exposure to the arc and / or welding. However, using a spring - loaded second contact tip not exposed to the arc and not exposed to welding improves the life of the spring - loaded contact tip. Since the torch accommodates different wire sizes, and the multi - size or general - purpose second tip improves convenience for the welding operator by reducing the number of tips (e.g., the first contact tip) that match the wire diameter. The construction of the spring - loaded contact tip can be one - piece (e.g., a tubular structure with slots to allow the teeth to adapt to different wire diameters and apply pressure and reliable contact), two - piece, or multi - piece. For welding operators accustomed to traditional torches (which only have a single contact tip (e.g., the tip closer to the arc)), the welding operator rarely or never needs to replace the second contact tip, thus improving the welding operator experience with multiple contact tips.

[0061] Figure 3A functional diagram of an exemplary contact tip assembly 206 is shown, which can be used with a welding system 100 that is either robotically operated or manually operated. As shown, the contact tip assembly 206 can include a first body portion 304, a shielding gas inlet 306, a first contact tip 318, a second body portion 310, a third body portion 312, a ceramic guide 314, a gas nozzle 316, and a second contact tip 308. Although the first body portion 304, the second body portion 310, and the third body portion 312 are shown as separate components, one of ordinary skill in the art will recognize after reading this disclosure that one or more of the body portions 304, 310, 312 can be manufactured as a single component. In some aspects, the contact tip assembly 206 can be added to an existing torch. For example, the contact tip assembly 206 can be attached to the distal end of a standard welding device and then used for resistance preheating. Similarly, the contact tip assembly 206 can be provided as a PLC retrofit with customized software, enabling integration with an existing system that already has a power source and a wire feeder.

[0062] In some examples, the first contact tip 318 and / or the second contact tip 308 are modular and / or removable so that the user of the welding system 100 can easily maintain them. For example, the first contact tip 318 and / or the second contact tip 308 can be implemented as replaceable cartridges. In some examples, the welding equipment 110 monitors one or more indicators that identify when the first contact tip 318 and / or the second contact tip 308 should be replaced, such as measurements of the following: the usage time of the first contact tip 318 and / or the second contact tip 308, the temperature of the first contact tip 318 and / or the second contact tip 308, the amperage in the first contact tip 318 and / or the second contact tip 308 and / or the wire, the voltage between the first contact tip 318 and / or the second contact tip 308 and / or the wire, the enthalpy or heat content to heat a given volume of wire to its melting point at the portion leaving the first contact tip 318, and / or any other data.

[0063] In operation, the electrode wire 114 passes through the gooseneck 204, through the first contact tip 318 and the second contact tip 308. Between them, the second power supply 302b generates a preheating current to heat the electrode wire 114. Specifically, the preheating current enters the electrode wire 114 via the second contact tip 308 and exits via the first contact tip 318. At the first contact tip 318, the welding current can also enter the electrode wire 114. The welding current is generated or otherwise provided by the first power supply 302a. The welding current exits the electrode wire 114 via the workpiece 106, thereby subsequently generating a welding arc 320. That is, when energy is provided for welding by the welding current, the electrode wire 114 carries a high electrical potential. When an arc is established between the electrode wire 114 and the target metal workpiece 106, the circuit is completed, and the welding current flows through the electrode wire 114, the arc 320, and the metal workpiece 106. The welding current melts the electrode wire 114 and the workpiece 106, thereby joining the workpiece when the melt solidifies. By preheating the electrode wire 114, the welding arc 320 can be generated with a significantly reduced arc energy. When the distance between the contact tips is 5.5 inches, the preheating current can be in the range of, for example, 75 A to 400 A. Generally, the preheating current is proportional to the distance between the two contact tips and the size of the electrode wire 114. That is, the smaller the distance, the greater the current required. The preheating current can flow in either direction between the electrodes.

[0064] Figure 3 Example power supplies 302a, 302b are controlled by an electrode preheating control circuit 322. As described in more detail below, the electrode preheating control circuit 322 controls the welding power and / or the preheating power output by the power supplies 302a, 302b based on a user input specifying the preheating power.

[0065] To avoid unwanted kinking, bending, or jamming of the electrode wire 114, a guide 314 can be provided to guide the electrode wire 114 as it travels from the second contact tip 308 to the first contact tip 318. The guide 314 can be made of ceramic, dielectric material, glass-ceramic polycrystalline material, and / or another non-conductive material. The contact tip assembly 206 can also include a spring-loading device or an equivalent device that reduces electrode wire kinking, bending, and jamming while increasing wire contact efficiency by keeping the electrode wire 114 taught and / or straight.

[0066] In some aspects, the second contact tip may be located at the wire feeder (e.g., at the welding apparatus 110) or at another extended distance to introduce a preheat current, in which case the preheat current may exit the contact tip in the gooseneck torch 108. The contact tip in the gooseneck torch 108 may be the same or different from the contact tip that introduces the welding current to the electrode wire 114. The preheat contact tip may be further positioned along the electrode wire 114 to facilitate use with a Push-Pull Gun, such as a Push-Pull Gun available from Miller Electric of Appleton, Wisconsin. The liner may be made of a ceramic roller, so that the preheat current may be re-injected at the wire feeder and have a very low value due to the length of the liner.

[0067] The welding current is generated or otherwise provided by a first power supply 302a, while the preheat current is generated or otherwise provided by a second power supply 302b. The first power supply 302a and the second power supply 302b may ultimately share a common power source (e.g., a common generator or line current connection), but the current from the common power source is converted, inverted, and / or regulated to produce two separate currents - the preheat current and the welding current. For example, a single power source and associated converter circuitry may be utilized to facilitate the preheat operation. In this case, three leads may extend from the welding apparatus 110 or auxiliary power leads in the welder, which may eliminate the need for the second power supply 302b.

[0068] In some aspects, instead of different contact tip assemblies 206, the first contact tip 318 and the second contact tip 308 may be located on each side of the gooseneck bend. For example, as Figure 2B shown, the preheat section may be curved (e.g., non-linear). That is, wire feeding occurs through a section of the torch having a bend greater than 0 degrees or a neck that is considered a "gooseneck". The second contact tip 308 may be located before the initial bend, and the first contact tip 318 may be located after the bend is complete. This arrangement may confer benefits to the connectivity of the heated wire moving through the neck portion between the two contact tips. This arrangement results in a more reliable connection between the two contact tips, where a dielectric insert that previously required off-axis machining was needed.

[0069] The preheat current and the welding current can be DC, AC, or a combination thereof. For example, the welding current can be AC while the preheat current can be DC, or vice versa. Similarly, the welding current can be DC electrode negative (DCEN) or various other power schemes. In some aspects, the welding current waveform can be further controlled, including constant voltage, constant current, and / or pulsed (e.g., AccuPulse). In some aspects, constant voltage and / or constant power, constant penetration, and / or constant enthalpy can be used instead of constant current to facilitate preheating. For example, the amount of penetration into the workpiece can be suitably controlled. In some aspects, the distance from the contact tip to the workpiece can vary, which will increase or decrease the welding current during constant voltage welding in order to maintain the voltage at or near the target voltage command, and thus change the amount of penetration / heat input into the weldment. By adjusting the preheat current amount in response to the change in the distance from the contact tip to the workpiece, the penetration / heat input can be advantageously controlled. Additionally, the penetration can be varied to reflect the desired weld / weld penetration profile. For example, the preheat current can be changed into various waveforms, such as but not limited to pulsed-type waveforms, to obtain the desired weld / weld penetration profile.

[0070] The current can be line frequency AC delivered from a simple transformer with primary phase control. Depending on how the control is implemented and the power supply configuration for the control, using CC, CV, or constant power can more simply control the current and voltage delivered to the preheat section. In another aspect, the welding power source for consumable arc welding (GMAW and SAW) can include regulating a constant welding current output and adaptively adjusting the wire feed speed to maintain the arc length or arc voltage setpoint (e.g., CC+V process control). In yet another aspect, the welding power source can include regulating a constant welding voltage output (or arc length) and adaptively adjusting the wire feed speed to maintain the arc current setpoint (e.g., CV+C process control). The CC+V and CV+C process controls allow for adapting to wire stickout changes and preheat current / temperature changes by adaptively adjusting the wire feed speed (or variable deposition). In yet another aspect, the power source can include regulating a constant welding current output, the wire feeder maintaining a constant deposition, and the preheat power source adaptively adjusting the preheat current (or preheat power) to maintain a constant arc voltage (or arc length). It can be understood that the increase in preheat current / power adds new degrees of freedom to the wire welding process (GMAW and SAW), which allows for flexibility and controllability in maintaining a constant weld penetration and weld width (arc current), deposition (wire feed speed), and process stability (arc length or voltage). These control schemes can be switched during the welding process. For example, CV+C is only used for arc starting while other control schemes are used for the main welding.

[0071] Using advanced controlled welding waveforms allows for reduced heat input, distortion, and improved bead geometry at high deposition rates. As a result, the operating range of pulsed welding is expanded, rotation transfer at high deposition rates is reduced, and spatter caused by rotary spray is reduced. By preheating the electrode wire 114, the operating range of the pulsed program can be extended to higher depositions. This is possible because the power required to transfer the material at these deposition rates is lower. Previously, at higher deposition rates, the pulse width / frequency / peak amperage was too high such that the benefits of the pulse no longer existed. By preheating the electrode wire 114, the operator can use a similar pulsed program for higher rates (e.g., 600 inches per minute (ipm)), which was previously only available at slower rates such as 300 ipm. Preheating the electrode wire 114 also maximizes the benefits of pulsed welding with low background current. Additionally, using the contact tip assembly 206 in combination with a metal core having a customized pulse configuration allows for higher quality, thicker deposition welding. By preheating the electrode wire 114, it behaves similar to solid wire and its transfer mode.

[0072] Additionally or alternatively, preheating the electrode wire 114 enables the background current of the pulse waveform to be significantly reduced because its main function can be changed from growing the ball to merely maintaining the arc between the electrode wire 114 and the workpiece 106. Conventionally, the background current of the pulse waveform is used to grow the droplet or ball, which is then deposited onto the workpiece 106. The example power supply 302a can implement the pulse waveform based on the preheat power applied to the electrode wire 114 by the preheat power supply 302b.

[0073] The welding system 100 can be configured to monitor the exit temperature (e.g., preheat temperature) of the electrode wire 114 between the preheat contact tips, as shown, between the first contact tip 318 and the second contact tip 308. The preheat temperature can be monitored using one or more temperature measuring devices (e.g., thermometers) that are positioned adjacent to the electrode wire 114 or otherwise operably positioned for periodic or real-time welding feedback. Example thermometers can include contact sensors and non-contact sensors such as non-contact infrared temperature sensors, thermistors, and / or thermocouples. The infrared thermometer measures the temperature based on the portion of the thermal radiation emitted by the electrode wire 114 to produce the measured preheat temperature. In addition to or instead of a thermometer, the temperature measuring device can include one or more sensors and / or algorithms that calculate the preheat temperature of the electrode wire 114. For example, the system can dynamically calculate the temperature based on, e.g., current or voltage. In some aspects, the thermometer can measure the temperature of the dielectric guide or the first contact tip to infer the wire temperature.

[0074] In operation, an operator can set a target preheat temperature, whereupon the welding system 100 dynamically monitors the preheat temperature of the electrode wire 114 and adjusts the preheat current via the second power supply 102b to compensate for any deviation (or other difference) between the measured preheat temperature and the target preheat temperature. Similarly, controls can be set so that a welding operation cannot be performed until the electrode wire 114 has been preheated to the predetermined preheat temperature.

[0075] As Figures 4A to 4C shown, the preheat torch can be combined with a submerged arc power supply for use in a single preheated wire, series preheated wire (two power supplies), and / or dual preheated wire configuration (one power supply). For example, Figure 4A shows a submerged arc (SAW) power supply in a single preheated wire configuration. The wire can be preheated with CV AC, CV EP, CV EN, CV+C AC, CV+C EP, CV+CEN, CC AC, CC EP, CC EN, CC+V AC, CC+V EP, and / or CC+V EN. Figure 4B shows a submerged arc power supply in a series preheated wire configuration. The wire can be used in a standard SAW configuration or any of the aforementioned variations. The wire can be preheated with CV AC, CVEP, CV EN, CV+C AC, CV+C EP, CV+C EN, CC AC, CC EP, CC EN, CC+V AC, CC+V EP, and / or CC+VEN. In some aspects, 1 wire can be preheated and is common (front-back wire). Additionally, different polarity combinations (EP, EN, AC, CV+C, CC+V) can be employed for each wire. For some applications, Figure 4B an example series SAW configuration in Figure 4C is where the lead arc is DCEP on an unheated solid wire for penetration and the trail arc is DCEN on a resistance preheated metal cored wire for deposition. Finally,

[0076] Figure 5 shows a functional diagram of another example contact tip assembly 500. The contact tip assembly 500 is similar to Figure 3The assembled component 206 shown. The assembled component 500 includes a power supply 302a to provide welding power to the electrode wire 114 (e.g., for generating a welding arc 320 or other welding power transfer). The assembled component 500 also includes a power supply 302b to generate a preheating current to heat the electrode wire 114.

[0077] The assembled component includes a first contact end 318 and a second contact end 308. The preheating power supply 302b has the same electrical connection as the second contact end 308 and the first contact end 318 referred to above Figure 3 described. Instead of the welding power supply 302a shown above being electrically connected to the first contact end 318 (e.g., via a positive polarity connection) and the workpiece 106 (e.g., via a negative polarity connection), the welding power supply 302a is electrically connected to the second contact end 308 via a positive polarity connection and to the workpiece 106 via a negative polarity connection. Figure 3

[0078] Figure 5 In Figure 5 the example assembled component, the preheating power supply 302b provides a preheating current to the portion of the electrode wire 114 between the contact ends 308, 318, which can occur before and / or during welding. In operation, the welding power supply 302a provides a welding current to support the arc 320. In Figure 5 the configuration, the energy provided by the welding power supply 302a also preheats the electrode wire 114 between the second contact end 308 and the arc 320. In some examples, the power provided by the preheating power supply 302b and the energy provided by the welding power supply 302a jointly preheat the electrode wire 114, thereby reducing the power delivered by the welding power supply 302a.

[0079] Figure 6 A functional diagram of another example contact end assembled component 600 is shown. The assembled component 600 is similar to Figure 5 the assembled component 500. However, the electrical connection between the preheating power supply 302b and the contact ends 308, 318 is reversed relative to Figure 5 the connection in

[0080] In exemplary assembly 600, when the welding power supply 302a is not providing power (e.g., when not welding), the power supply 302b can provide preheat power to the portion of the wire between the contact ends 308, 318. When the welding power supply 302a provides welding power to the assembly 600, the preheat power supply 302b is turned off and / or used to reduce a portion of the welding power provided by the welding power supply 302a to control the preheating of the electrode wire 114 by the welding power supply 302a.

[0081] Figure 7 A functional diagram of another exemplary contact end assembly 700 is shown. Assembly 700 includes a power supply 302a to provide welding power to the electrode wire 114 (e.g., for generating a welding arc 320 or other welding power transfer). Assembly 700 also includes a power supply 302b to generate a preheat current to heat the electrode wire 114. The welding power supply 302a is electrically connected to the first contact end 318 (e.g., via a positive polarity connection) and the workpiece 106 (e.g., via a negative polarity connection).

[0082] In Figure 7 assembly 700, the preheat power supply 302b is electrically connected to the electrode wire 114 such that the welding current provided by the power supply 302a does not superimpose on the wire with the preheat current provided by the preheat power supply 302b. To this end, exemplary assembly 700 includes a third contact end 702 to which the preheat power supply 302b is electrically connected. Although in the Figure 7 exemplary shown the preheat power supply 302b is electrically connected to the third contact end 702 via a positive connection and to the second contact end 308 via a negative connection, in other examples the polarities of the connections are reversed.

[0083] Figure 8 A functional diagram of another exemplary contact end assembly 800 is shown. Assembly 800 includes a single power supply that provides preheat power and welding power to the electrode wire 114 via the first contact end 318 and / or the second contact end 308. To control the direction of the preheat and / or welding power supplied to the contact ends 308, 318, assembly 800 includes a preheat / welding switch 802. The preheat / welding switch 802 switches the electrical connection between the welding power supply 302a and the first contact end 318, the second contact end 308, and / or the workpiece 106.

[0084] The welding power supply 302a provides preheating to the electrode wire 114 by, for example, controlling the preheat / weld switch 802 to connect the positive terminal of the welding power supply 302a to one of the contact ends 308, 318 and the negative terminal of the welding power supply 302a to the other of the contact ends 308, 318. The welding power supply 302a provides welding to the electrode wire 114 by, for example, controlling the preheat / weld switch 802 to connect the positive terminal of the welding power supply 302a to one of the workpieces 106 or one of the contact ends 308, 318, and the negative terminal of the welding power supply 302a to the other of the workpieces 106 or one of the contact ends 308, 318 (e.g., based on whether DCEN or DCEP is being used).

[0085] If the preheat / weld switch 802 connects one of the terminals of the welding power supply 302a to the second contact end 308 and the other terminal of the welding power supply 302a to the workpiece 106, the welding current provided by the welding power supply 302a also provides preheating to the electrode wire 114. In some examples, the preheat / weld switch 802 alternates between connecting the welding power supply 302a to a first set of electrical connections for preheating the electrode wire 114 (e.g., connecting to the contact ends 308, 318), connecting to a second set of electrical connections for welding (e.g., connecting to the workpiece 106 and the first contact end 318), and / or connecting to a third set of electrical connections for simultaneously preheating the electrode wire 114 and welding (e.g., connecting to the workpiece 106 and the second contact end 308).

[0086] Figure 9 An example welding assembly 900 is shown that includes voltage sensing leads 902, 904 to measure the voltage drop across the two contact ends 308, 318 for preheating the electrode wire 114. The preheat monitor 906 monitors for heating anomalies by comparing the measured voltage to a target voltage level, by evaluating the time derivative and / or integral of the measured voltage, and / or by statistical analysis (e.g., mean, standard deviation, root mean square (RMS) value, minimum, maximum, etc.). Additionally or alternatively, the preheat monitor 906 monitors the stability of the voltage over a long-term history (e.g., over seconds, minutes, and / or hours). Additionally or alternatively, the preheat monitor 906 monitors the preheat current, preheat power, preheat heat content or enthalpy, and / or preheat circuit impedance via the preheat power supply 302b.

[0087] Some example welding systems 100 use radiant heating to heat the electrode wire 114 via a wire liner. One example includes constructing a coiled wire liner using nichrome, platinum, and / or other suitable materials to physically support and / or guide the electrode wire 114 from a wire supply source to a welding torch while simultaneously heating the electrode wire 114. The wire liner is heated by an example preheat power supply 302b. A higher heating current can be used to heat a shorter portion of the wire liner, and / or a reduced heating current can be used to heat a longer portion of the wire liner (e.g., the majority of the wire liner extending from a wire feeder to a welding torch). The electrode wire 114 is gradually heated by the wire liner using radiant heating such that when the electrode wire 114 reaches the welding torch and / or a first contact tip 318, the electrode wire 114 has an elevated temperature.

[0088] Additionally or alternatively, the welding system 100 can use an infrared heating lamp mounted within the gun body to preheat the electrode wire 114. The infrared heating lamp is powered by the preheat power supply 302b.

[0089] Examples of the present disclosure can be used to perform a cladding operation while reducing dilution of a substrate material. In such examples, the preheat power supply 302b provides a high preheat power to preheat the wire to near melting. The welding power supply 302a then provides a relatively low arc current (e.g., 15 - 200 A) to bring the wire tip to an actual melting point. However, because a relatively low current (e.g., 15 - 200 A) may not be sufficient to cause the molten wire to detach and transfer liquid metal across the arc, some such examples use a fast response motor to oscillate the wire. Oscillation of the wire causes the liquid metal to vibrate or oscillate off of the wire tip. Examples of such oscillation techniques are described in Y. Wu and R. Kovacevic, “Mechanically assisted droplet transfer process in gas metal arc welding,” Proceedings of the Institution of Mechanical Engineers Vol 216 Part B: J Engineering Manufacture, p. 555, 2002, the entire content of which is incorporated herein by reference. By using a low arc current, example cladding methods reduce substrate metal dilution and / or reduce the cost of the method such as laser cladding.

[0090] In some other examples, the cladding system uses resistance preheating of the electrode wire and a laser energy source to deposit the cladding. The laser beam can be defocused, and there is no welding arc (such as an electric arc) during the cladding operation. In some cases, the welding arc is prevented by a voltage clamping system that clamps the voltage between the wire and the workpiece to less than the arc starting voltage. Such a clamping system can include diodes and / or transistors.

[0091] In some examples, a welding-type device can be used to perform metal additive manufacturing and / or additive metal coating. For example, a coating system or an additive manufacturing system uses wire preheating and voltage clamping as described above, but omits the laser. In some other examples, the cladding system uses wire preheating and omits both the clamping and the laser. In either case, the metal may not have to be bonded to the workpiece, but rather a coating can be formed and / or laid on a substrate, and the metal can subsequently be removed from the substrate.

[0092] In some examples, the cladding system uses resistance preheating to preheat the wire. A TIG welding arc or a plasma preheating arc is used to melt the preheated wire.

[0093] Some example cladding systems use a preheating system to perform pilot preheating (e.g., before the wire contacts the workpiece, where the two tips in the torch are preheated) and transferred preheating (e.g., once current starts to flow in the work lead, the tip closer to the workpiece is turned on). The cladding system switches the preheating system between the pilot preheating mode and the transferred preheating mode.

[0094] In some cases, preheating an electrode with an extended stickout length may suffer from instability, which is caused by the short-circuit control response in the submerged arc welding and / or GMAW processes. The traditional short-circuit control response is to increase the current to clear the detected short circuit. However, the increase in current overheats the extended portion to a very high temperature, causing the wire to lose rigidity and / or mechanical stability. Therefore, when the welding system 100 attempts to obtain a stable arc length or the distance between the contact tip and the workpiece, the overheated wire portion melts at a higher rate than normal and may introduce arc length variations or oscillations. Some examples address this instability by using a current-controlled (e.g., constant current) mode to control the welding power supply 302a during an extended short-circuit event (e.g., a short circuit lasting more than 5 ms). The current-controlled mode does not include the shark fin-shaped response or high-simulation inductance typical of short-circuit clearing methods. For example, for this wire feed rate (e.g., high current) or a fixed low current (e.g., 50 A or less), the current-controlled mode may use the same average current as that used in the spray mode. The welding system 100 may also initiate wire retraction to clear the short circuit. After the short circuit is cleared, the welding system 100 resumes the mode to a voltage-controlled (e.g., constant voltage) spray and / or pulsed spray mode. In such examples, the wire drive motor is highly responsive (e.g., similar to the motor used in the controlled short-circuit (CSC) mode), but the duty cycle is reduced relative to the duty cycle used in the CSC mode. In such examples, the motor is not used as quickly to clear the short circuit as in the CSC mode.

[0095] Some examples increase the deposition rate of the weld while reducing the heat input to the workpiece using a spray mode. The welding system 100 switches between a spray mode at a low wire speed mode and a cold wire feed at a higher wire speed mode. In this document, cold wire refers to wire that is not melted, whether preheated or not. In some such examples, the welding system 100 preheats the electrode wire 114 and performs welding in a spray mode (e.g., voltage controlled and / or pulsed), then reduces the current to a lower current level (e.g., 50 A or less). After operating in the spray mode for a period of time, the welding system 100 accelerates the wire feed rate (e.g., accelerates to the maximum motor feed rate) to feed cold (e.g., unmelted) electrode wire 114 into the weld pool. The input of the cold wire both adds filler metal and cools the weld pool. Before the weld pool cools too much to further melt the wire, preheated wire is used to increase the deposition of wire into the weld pool, but preheating of the wire can be omitted. The welding system 100 then retracts the wire while maintaining a low welding current to clear the short circuit. When the arc restarts, the welding system 100 returns to the spray mode at a higher current and feeds the electrode wire 114 at a lower wire feed rate. In some examples, when feeding cold wire into the weld pool to increase deposition, the welding system 100 maintains a high current but reduces the current (e.g., reduces to 50 A or less) before retracting the wire to reduce spatter during arc restart. In such examples, the wire drive motor is highly responsive (e.g., similar to the motor used in a controlled short circuit (CSC) mode), but has a lower duty cycle relative to the duty cycle used in the CSC mode. In such examples, the motor is not used as quickly to clear the short circuit as in the CSC mode.

[0096] In some cases, poor physical contact between the electrode wire 114 and the contact tip 318 may cause an arc discharge between the electrode wire 114 and the contact tip 318, which may damage the contact tip 318. Examples of the present disclosure include a clamping diode therebetween (e.g., a Zener diode, a transient voltage suppression diode, a buffer circuit, and / or a combination thereof, which may be located inside the torch near the contact tips 308, 318) to clamp the output voltage of the preheating power supply 302b to less than a threshold (e.g., less than 14V). Using the clamping diode reduces or eliminates the possibility of arcing between the contact tips 308, 318 and the electrode wire 114. Additionally, the clamping diode reduces the possibility of arcing in the first contact tip 318 by the main welding current. When there is poor physical contact between the electrode wire 114 and the first contact tip 318, the arc current can be conducted or redirected via the clamping circuit and the second contact tip 308 to the electrode wire 114 to prevent tip burn - off and extend the life of the first contact tip 318. The clamping diode is selected to have a current capacity to conduct both the preheating current and the welding current (e.g., having a conduction time of several hundred nanoseconds). In some examples, the clamping diode is a silicon carbide rectifier diode.

[0097] In some examples, the second contact tip 308 is used as a sensor to detect arc - discharge conditions at the first contact tip 308 (e.g., without preheating the electrode wire 114). When such a condition of arcing at the first contact tip 318 is detected, the welding system 100 clamps the tip - to - wire contact voltage as described above.

[0098] Although the examples disclosed above include coaxially - aligned contact tips 308, 318, in other examples, the axes of the contact tips 308, 318 are offset (e.g., parallel but misaligned) and / or tilted (e.g., not parallel). In some other examples, a meandering or curved wire support (e.g., ceramic) is provided between the two contact tips 308, 318 to improve the contact at the first contact tip 308. In some other examples, the first contact tip 318 is provided with a spring - loaded contact to contact the electrode wire 114, thereby ensuring contact between the first contact tip 318 and the electrode wire 114.

[0099] Figure 10FIG. 1000 shows an example welding assembly 1000 that includes an enthalpy measurement circuit 1002. The enthalpy measurement circuit 1002 determines the enthalpy applied to workpiece 106. The enthalpy applied to workpiece 106 by power supplies 302a, 302b is the sum of the enthalpy introduced into electrode wire 114 by preheat power supply 302b and the enthalpy introduced by welding power supply 302a. Example measurement circuit 1002 can determine enthalpy based on the measured arc voltage, the measured welding-type current, and / or the measured preheat current, or the voltage drop across a portion of the electrode. The electrode preheat circuit 1002 controls the preheat current based on the determined enthalpy and the target enthalpy to be applied to workpiece 106. For example, the electrode preheat circuit 1002 can reduce the preheat current provided by preheat power supply 302b based on the welding power applied by welding power supply 302a to maintain a constant enthalpy applied to workpiece 106. The welding power supply 302a can provide variable power based on, for example, changes in the contact tip-to-workpiece distance and / or arc length.

[0100] In some examples, welding system 100 includes an extension sensing circuit that determines the electrode extension distance of electrode wire 114. The preheat power supply 302b controls the preheat current based on the electrode extension distance. Example extension sensing circuits include current sensors to measure the welding current provided by welding power supply 302a and determine the electrode extension distance based on the measurement of the welding-type current.

[0101] Figure 11 FIG. 1104 shows an example implementation that provides a resistance preheated wire 1102 to workpiece 1104 and provides a separate arc source (e.g., tungsten electrode 1106) to melt the wire 1102 and / or workpiece 1104. The wire 1102 is preheated using contact tips 1108 and 1110 electrically coupled to preheat power supply 1112. Example contact tips 1108, 1110 and preheat power supply 1112 can be implemented as described in any of the examples of FIGS. Figure 3 、 5 、6、7、9 and / or 10. The preheat power supply 1112 can be DC, AC, and / or DC with an AC component.

[0102] The tungsten electrode 1106 generates an arc 1114. A gas nozzle 1116 is configured in the same torch as the tungsten electrode 1106 and provides a shielding gas 1118. A wire feeder 1120 enables the wire 1102 to travel bidirectionally forward and / or backward. The wire feeder 1120 can be a reciprocating wire feeder or a non-reciprocating wire feeder. Reciprocating the preheated wire 1102 increases the welding or cladding travel speed and, when certain reciprocation frequencies are used, produces a grain refinement effect.

[0103] For welding, an example preheat power supply 1112 preheats wire 1102 via contact tips 1108, 1110, and a tungsten electrode 1106 provides additional heat required to melt a portion of the wire 1102 and / or workpiece 1104 into a weld pool 1122. The preheated wire 1102 melts after being submerged into the weld pool 1122, is melted by an electric arc 1114, and / or both. Any of the example control processes described herein can be used to perform welding, brazing, cladding, hardfacing, metal additive, and / or any other welding-type operation.

[0104] Figure 12 An example implementation is shown that provides a resistively preheated wire 1202 to a workpiece 1204 and provides a separate arc source (e.g., one or more laser heads 1206) to melt the wire 1202. Figure 12 Examples of Figure 11 include contact tips 1108 and 1110, a preheat power supply 1112, and a wire feeder 1120. Example contact tips 1108, 1110, and preheat power supply 1112 can be implemented as described in any of the examples of Figure 3 , 5 , 6, 7, 9, and / or 10.

[0105] Similar to Figure 11 tungsten electrode 1106, Figure 12 laser head 1206 provides sufficient power to melt workpiece 1204 to create a weld pool 1122 and submerges the preheated wire 1202 into the weld pool to melt the preheated wire 1202 for metal deposition. The use of the preheated wire 1202 includes applying less energy to workpiece 1204 by laser head 1206 than is required when using a cold wire. In some cases, the preheated wire 1102 melts after being submerged into workpiece 1104 and / or weld pool 1122 without additional heat from the laser. In other cases, the laser adds more heat to the wire to be melted into the weld pool 1122. The reduced laser power and heat help reduce the dilution of the base metal of workpiece 1104 in a corrosion-resistant hardfacing layer. Thus, Figure 11 and / or 12 can achieve a higher deposition rate than a conventional cold wire welding process while being less likely to burn through workpieces 1104, 1204.

[0106] In some examples, the welding system 100 responds to a wire short circuit event. The example welding system 100 uses feedback to immediately turn off the preheat power to prevent the soft preheated wire from being compressed and causing a blockage between the first contact tip 318 and the second contact tip 308. The welding system 100 uses feedback such as from a wire feed motor (e.g., motor current, motor torque, etc.) and / or another wire feed force sensor between two tip motor currents or other feed force sensors to provide rapid detection. Additionally or alternatively, the welding system 100 uses feedback such as the duration of a short circuit measurement (e.g., arc voltage) to detect a wire stubbing event (e.g., extinguishing the arc by contacting the electrode wire 114 with the workpiece 106). In response to detecting the event, the welding system 100 turns off or disables the preheat power supply to prevent wire noodling between the contact tips. Alternatively, in response to detecting the event, the amount of wire preheating can be reduced. In some examples, depending on the duration of the event, the amount of preheat can be further reduced (e.g., by stepping and / or ramping).

[0107] In some examples, the welding system 100 includes a welding-type power source to provide welding-type power to a welding-type circuit, where the welding-type circuit includes a first contact tip of a welding-type electrode and a torch, as described herein. The example welding system 100 also includes one of the example preheat circuits disclosed herein, the preheat circuit providing preheat power via the second contact tip of the torch through a first portion of the welding-type electrode. Examples of the present disclosure also include an electrode preheat control circuit 322 configured to control the preheat power based on a user input specifying the preheat power.

[0108] In some examples, the welding apparatus 110 includes a user interface device or communicates with a user interface device to enable a user to adjust one or more preheat effects and / or parameters. For example, the user interface device can receive a selection of the preheat power, and the electrode preheat control circuit 322 controls the preheat power and the welding-type power based on the selection. Figure 13 An example user interface device 1300 is shown, which can be used to implement the user interface of the welding apparatus. The example user interface 1300 can be implemented alone or as part of a larger welding user interface that allows control of other aspects of the welding apparatus 110 (e.g., voltage, current, and / or wire feed speed set points, etc.).

[0109] The welding apparatus 110 may use default voltage commands, default current commands, default power commands, and / or default enthalpy commands for a preheating power source (e.g., power supplies 302a, 302b) corresponding to wire speed, joint thickness, and / or joint geometry. However, for all cases, such default commands may not always be the amounts desired by the user. For example, an operator may desire to slightly change the commands to control the amount of penetration and / or the amount of heat input, which in turn can mitigate welding distortion. The exemplary user interface 1300 enables the user to fine-tune the preheating portion of the welding conditions to meet a particular application. The user interface 1300 enables the user to select one or more of preheating current, preheating voltage, preheating power, or preheating enthalpy.

[0110] The exemplary user interface 1300 includes a preheat adjustment device 1302 and one or more preheat indicator devices 1304, 1306. In Figure 13 the example, the preheat adjustment device 1302 is a dial that allows the user to increase and / or decrease the preheat level implemented by the welding apparatus 110 (e.g., via Figure 3 、 5 any one of the example assemblies 206, 500, 600, 700, 800, 900, 1000 of 6, 7, 8, 9, or 10).

[0111] The user interface 1300 displays a value representing preheating power and / or welding-type power, and updates the value in response to a selection of a preheating power level. In Figure 13 the example, the digital preheat indicator 1306 represents a numerical indication of the effect of changing the preheat level 1308 via the preheat adjustment device 1302 on the welding.

[0112] For example, the digital preheat indicator 1306 displays the average heat input into the welding based on the preheat level 1308. Figure 14A 、 14B and 14C illustrate example average heat inputs for different preheat levels. The system 100 may adjust the welding-type power in response to a change in preheating power by the user, and / or vice versa. Other example numerical indications include voltage commands, preheating current, total system energy, and / or efficiency.

[0113] The user interface 1300 also displays the value with reference to a selected range of allowable values. For example, relative to the default preheat level 1310 and relative to the allowable range of preheat levels, the graphical preheat indicator 1304 device graphically indicates to the user the preheat level 1308 selected via the preheat adjustment device 1302. The graphical preheat indicator 1304 also includes an identifier that indicates the effect of adjusting the preheat level on the welding penetration and / or other effects. For example, the graphical preheat indicator 1304 indicates that as the preheat level increases, the welding penetration decreases, and conversely, as the preheat level decreases, the welding penetration increases. AsFigure 14A , 14B As shown in FIGS. 14B and 14C, when the graphical preheat indicator 1304 is adjusted, the preheat level 1308 is graphically represented as shifting left and right.

[0114] Figure 13 , Figures 14A - 14C The user interface 1300 of FIGS. 14A-14C can use a preheat upper limit and / or a preheat lower limit to restrict the selection of preheat power. For example, when the preheat upper limit or lower limit has been reached, the user interface 1300 can restrict the range of the adjustment knob 1302 and / or restrict an increase or decrease in preheat power in response to the adjustment knob 1302.

[0115] In some examples, the user interface 1300 can receive user input as a specific requirement for the ratio of preheat power to weld-type power. The indicator devices 1304, 1306 (e.g., display devices) can display the balance between preheat power and weld-type power, display the total heat input of the preheat power and the weld-type power, and / or update the display of the balance and the total heat input in response to a change in the user input. Additionally or alternatively, the user interface 1300 can receive a selection of a weld penetration amount and / or a wire deposition rate. Similar to the selection of preheat power, the user interface 1300 can restrict the selection of the weld penetration amount to a penetration upper limit and / or a penetration lower limit and / or restrict the selection of the wire deposition rate to a wire deposition rate upper limit and / or a wire deposition rate lower limit. In some such examples, the user interface 1300 shows the effect of changing the weld penetration on the preheat power, the weld power, the heat input, the weld voltage, the preheat voltage, the preheat wattage, the weld wattage, the weld current, and / or the preheat current, and the electrode preheat control circuit 322 controls the preheat power and the weld-type power based on the selection of the weld penetration amount. For example, the electrode preheat control circuit 322 can decrease the preheat power and increase the weld-type power in response to an increase in the selected weld penetration, and / or increase the preheat power and decrease the weld-type power in response to a decrease in the selected weld penetration. When the user selects a wire deposition rate, the electrode preheat control circuit 322 can increase the preheat power and increase the wire feed speed of the electrode in response to an increase in the selected wire deposition rate, and / or decrease the preheat power and decrease the wire feed speed of the electrode in response to a decrease in the selected wire deposition rate.

[0116] The user interface 1300 may implement a selection of any one and / or combination of the following: preheat current, preheat voltage, preheat wattage, impedance, electrode preheat temperature, power balance between preheat wattage and arc wattage, total heat input to the weld, preheat enthalpy, and / or any other aspect of preheat power controllable via the electrode preheat control circuit 322. The user interface 1300 may additionally or alternatively implement a selection of voltage balance, wattage balance, current balance, heat balance, and / or enthalpy balance between the electrode preheat circuit and the welding type circuit. Additionally, any selection that may be implemented via the user interface 1300 may be automatically selected by the electrode preheat control circuit 322, e.g., automatically based on one or more aspects of the weld to be performed in response to a user request. For example, the user may use the user interface 1300 to select one or more of a penetration value, workpiece thickness, or wire diameter of the welding type electrode wire 114, and the electrode preheat control circuit 322 controls the preheat power and / or welding type power based on the aspects of the weld input by the user.

[0117] In addition to or as an alternative to the user interface 1300, the system 100 may implement operator control of preheat power such as voltage, current, wattage, enthalpy, impedance, heat input, and / or penetration using fingertip control (e.g., on the torch 108), foot control (e.g., similar to a foot pedal used in GTAW), and / or any other control device that enables a user to control preheat power during welding.

[0118] Figure 15 An example welding assembly 1500 is shown that uses a welding control circuit 1504 that includes a user interface 1502 and implements a preheat control loop 1506. Figure 16a is a block diagram of an example implementation of the preheat control loop 1506. The user interface 1502 includes Figure 13 the user interface 1300 or another interface that enables a user of the welding assembly 1500 to adjust the preheat level. The welding control circuit 1504 receives the preheat level (or penetration level) selected via the user interface 1502 and controls the power supply 302b to change the preheat level. The welding control circuit 1504 may further control the power supply 302a to adjust one or more aspects of the welding power based on the selected preheat level to improve performance at the selected preheat level. The welding control circuit 1504 is configured to control the preheat power based on at least one of a target total heat input for welding, travel speed, target bead width, or target penetration. An example welding control circuit 1504 may implement the electrode preheat control circuit 322.

[0119] Figure 16aAn example preheat control loop 1506 automatically controls the preheat power 1602 supplied to the welding process 1604 by using feedback from the penetration sensor 1606 to maintain a constant penetration. An example penetration sensor uses the welding current as a measure of the welding penetration. The interruption of the pulse voltage signature caused by the metal vapor pressure can be an early indication of burn-through. The example preheat control loop 1506 uses the penetration sensor 1606 as a closed-loop feedback (e.g., subtracting the feedback from the desired penetration and / or preheat level 1608 input from the user interface 1502). The preheat control loop 1506 can improve poor penetration (e.g., partial penetration) and / or prevent burn-through by detecting the penetration and then independently adjusting the penetration using the preheat power without introducing process instability. Other example penetration sensors that can be used include infrared sensors outside the welding arc and the weld pool.

[0120] Figure 16b Shows Figure 15 Another example implementation of the preheat control loop 1506. Figure 16b The preheat control loop 1506 automatically controls the preheat power 1602 supplied to the welding process 1604 based on a user input 1610 specifying the preheat power. For example, as Figure 13 shown, the user input 1610 can increase or decrease the preheat power through the preheat adjustment device 1302. The user input 1610 can control the preheat current, preheat voltage, preheat power, and / or preheat enthalpy. As described above, the user input 1610 can be limited by an upper limit value and / or a lower limit value.

[0121] Figure 16b The preheat control loop 1506 accesses the preheat feedback 1612. The preheat feedback can be the measured preheat voltage, measured preheat current, measured preheat power, measured preheat enthalpy, measured electrode wire temperature, and / or any other feedback.

[0122] Figure 16b Also shown is the welding power level 1614 as an input to the welding control loop 1616. The welding power level 1614 can be, for example, the target welding current for a current-controlled welding process and / or the target welding voltage for a voltage-controlled welding process. The welding control loop 1616 outputs the welding power 1618, and the welding power 1618 is combined with the preheat power 1602 for the welding process 1604. The welding control loop 1616 also receives the welding feedback 1620, such as the measured arc voltage or measured arc current.

[0123] When the user changes the preheat level 1610, the corresponding change in the preheat power 1602 affects the welding process 1604, the welding feedback 1620, and the welding power 1618. For example, if the user increases the desired preheat level 1610 while the welding power level 1614 is maintained at a constant voltage level, the control loop 1616 reduces the welding power 1618 by reducing the welding current so that the total power input and / or the total heat input remains the same. However, since the ratio of the preheat power to the welding power increases, the welding penetration may decrease.

[0124] As Figure 16b shown, the electrode preheat control circuit 322 and / or the welding control circuit 1504 are configured to control the welding-type power based on the preheat power.

[0125] Returning to Figure 15 , the example assembly 1500 also includes voltage sensing leads 1508, 1510 to measure the voltage across the preheated portion of the electrode wire 114. The voltage sensing leads 1508, 1510 may be coupled to, for example, two contact tips 308, 318, a wire liner, a wire drive motor, a diffuser in the torch, and / or any other generally electrically equivalent points. The welding control circuit 1504 uses the preheat control loop 1512 to control the preheat power supply 302b. The preheat control loop 1512 uses the voltage sensed via the leads 1508, 1510 and the current output by the power supply 302b to maintain the commanded power input, current input, voltage input, enthalpy, and / or impedance of the portion of the electrode wire 114. In Figure 15 the example, the preheat control loop 1512 uses the error between the commanded preheat voltage and the voltage sensed via the sensing leads 1508, 1510 to regulate the preheat current, the preheat voltage, and / or the preheat power.

[0126] In some examples, the welding control circuit 1504 controls the preheat level 1610 and the welding power level 1614, and modifies the welding power level 1614 in response to a change in the preheat level 1610 by the user. Additionally or alternatively, the preheat level 1610 and / or the welding power level 1614 may be specified by the user based on a target heat input, a target preheat power level, a target ratio between the preheat power and the welding-type power, and / or a target arc penetration.

[0127] Figure 17 is Figure 3 , 5Block diagram of an example implementation of power supplies 302a, 302b for 6, 7, 8, 9, 10, and / or 15. The example power supplies 302a, 302b provide power for a welding application, control, and supply consumables. In some examples, the power supplies 302a, 302b directly provide input power to the torch 108. In the example shown, the welding power supplies 302a, 302b are configured to provide power for a welding operation and / or a preheating operation. The example welding power supplies 302a, 302b also provide power to a wire feeder to supply electrode wire 114 to the torch 108 for various welding applications (e.g., GMAW welding, flux-cored arc welding (FCAW)).

[0128] The power supplies 302a, 302b receive main power 1708 (e.g., from an AC or DC power grid, an engine / generator set, a battery, or other energy generation or storage device, or a combination thereof), condition the main power, and provide output power to one or more welding devices and / or preheating devices according to the needs of the system. The main power 1708 can be supplied from an off-site location (e.g., the main power can be sourced from a power grid). The welding power supplies 302a, 302b include a power converter 1710, which can include a transformer, a rectifier, switches, and the like, and is capable of converting AC input power into AC and / or DC output power according to the needs of the system (e.g., a specific welding process and mode). The power converter 1710 converts the input power (e.g., the main power 1708) into welding-type power based on a welding voltage setpoint and outputs the welding-type power via a welding circuit.

[0129] In some examples, the power converter 1710 is configured to convert the main power 1708 into both a welding-type power output and an auxiliary power output. However, in other examples, the power converter 1710 is adapted to convert the main power only into a welding power output and provide a separate auxiliary converter to convert the main power into auxiliary power. In some other examples, the power supplies 302a, 302b directly receive a converted auxiliary power output from a wall outlet. The power supplies 302a, 302b can employ any suitable power conversion system or mechanism to generate and provide both welding power and auxiliary power.

[0130] Power supplies 302a, 302b include a controller 1712 to control the operation of power supplies 302a, 302b. The welding power supplies 302a, 302b also include a user interface 1714. The controller 1712 receives inputs from the user interface 1714 through which the user can select a process and / or enter desired parameters (e.g., voltage, current, specific pulsed or non-pulsed welding scenarios, and the like). The user interface 1714 can use any input device such as a keypad, keyboard, buttons, touch screen, voice-activated system, wireless device, etc. to receive inputs. In addition, the controller 1712 controls the operating parameters based on the user's inputs and based on other current operating parameters. Specifically, the user interface 1714 can include a display 1716 to facilitate presenting, showing, or indicating information to the operator. The controller 1712 can also include interface circuitry to facilitate transferring data to other devices in the system, such as a wire feeder. For example, in some cases, power supplies 302a, 302b communicate wirelessly with other welding devices within the welding system. Additionally, in some cases, power supplies 302a, 302b communicate with other welding devices using a wired connection, such as by using a network interface controller (NIC) to transfer data over a network (e.g., Ethernet, 10baseT, 10base100, etc.). In Figure 1 the example, the controller 1712 communicates with the wire feeder via a communication transceiver 1718 via the welding circuit.

[0131] The controller 1712 includes at least one controller or processor 1720 that controls the operation of the welding power supply 1702. The controller 1712 receives and processes a plurality of inputs associated with the performance and requirements of the system. The processor 1720 can include one or more microprocessors, such as one or more “general-purpose” microprocessors, one or more dedicated microprocessors and / or ASICs, and / or any other type of processing device. For example, the processor 1720 can include one or more digital signal processors (DSPs).

[0132] An example controller 1712 includes one or more storage devices 1723 and one or more memory devices 1724. The storage device 1723 (e.g., non-volatile storage) can include ROM, flash memory, hard disk drive, and / or any other suitable optical storage medium, magnetic storage medium, and / or solid-state storage medium, and / or a combination thereof. The storage device 1723 stores data (e.g., data corresponding to welding applications), instructions (e.g., software or firmware for performing a welding process), and / or any other appropriate data. Examples of stored data for welding applications include the posture (e.g., orientation) of the torch, the distance between the contact tip and the workpiece, voltage, current, welding equipment settings, and the like.

[0133] The memory device 1724 may include volatile memory (e.g., random access memory (RAM)) and / or non-volatile memory (e.g., read-only memory (ROM)). The memory device 1724 and / or the storage device 1723 may store various information and may be used for various purposes. For example, the memory device 1724 and / or the storage device 1723 may store processor-executable instructions 1725 (e.g., firmware or software) for execution by the processor 1720. Additionally, one or more control schemes for various welding processes, along with associated settings and parameters, may be stored in the storage device 1723 and / or the memory device 1724 together with code configured to provide a specific output during operation (e.g., initiate wire feeding, enable gas flow, capture welding current data, detect short circuit parameters, determine spatter amount).

[0134] In some examples, welding power flows from the power converter 1710 through the welding cable 1726. The exemplary welding cable 1726 is attachable and detachable from the welding stud at each of the welding power supplies 302a, 302b (e.g., to enable easy replacement of the welding cable 1726 in the event of wear or damage). Additionally, in some examples, welding data is provided with the welding cable 1726 such that the welding power and the welding data are provided and transmitted together through the welding cable 1726. The communication transceiver 1718 is communicatively coupled to the welding cable 1726 to transmit (e.g., send / receive) data through the welding cable 1726. The communication transceiver 1718 may be implemented based on various types of power line communication methods and techniques. For example, the communication transceiver 1718 may utilize the IEEE standard P1901.2 to provide data communication through the welding cable 1726. In this way, the welding cable 1726 can be used to supply welding power from the welding power supplies 302a, 302b to the wire feeder and the torch 108. Additionally or alternatively, the welding cable 1726 can be used to send data communication to and / or receive data communication from the wire feeder and the torch 108. The communication transceiver 1718 is communicatively coupled to the welding cable 1726 via, for example, a cable data coupler 1727 to characterize the welding cable 1726, as described in more detail below. The cable data coupler 1727 may be, for example, a voltage or current sensor.

[0135] In some examples, the power supplies 302a, 302b include or are implemented in a wire feeder.

[0136] Example communication transceiver 1718 includes a receiver circuit 1721 and a transmitter circuit 1722. Generally, the receiver circuit 1721 receives data sent by the wire feeder via a welding cable 1726, and the transmitter circuit 1722 sends data to the wire feeder via the welding cable 1726. As described in more detail below, the communication transceiver 1718 allows remote configuration of the power supplies 302a, 302b from the location of the wire feeder and / or compensation of the welding voltage by the power supplies 302a, 302b using welding voltage feedback information sent by the wire feeder 104. In some examples, the receiver circuit 1721 receives communication via the welding circuit when welding current is flowing through the welding circuit (e.g., during a welding-type operation) and / or after the welding current has stopped flowing through the welding circuit (e.g., after a welding-type operation). Examples of such communication include welding voltage feedback information measured at a device remote from the power supplies 302a, 302b (e.g., the wire feeder) when welding current is flowing through the welding circuit.

[0137] An example implementation of the communication transceiver 1718 is described in U.S. Patent No. 9,012,807. The entire content of U.S. Patent No. 9,012,807 is incorporated herein by reference. However, other implementations of the communication transceiver 1718 may be used.

[0138] Example wire feeder 104 also includes a communication transceiver 1719, which may be similar or identical to communication transceiver 1718 in construction and / or function.

[0139] In some examples, a gas supply 1728 provides a shielding gas, such as argon, helium, carbon dioxide, and the like, for a welding application. The shielding gas flows to a gas flow valve 1730, which controls the flow of the gas, and if desired, the valve may be selected to allow modulation or regulation of the amount of gas provided to the welding application. The valve 1730 may be opened, closed, or otherwise operated by a controller 1712 to allow, inhibit, or control the gas flow (e.g., the shielding gas) through the valve 1730. The shielding gas exits the valve 1730 and flows via a cable 1732 (in some implementations, the cable 1732 may be encapsulated with the welding power output) to the wire feeder, which provides the shielding gas to the welding application. In some examples, the power supplies 302a, 302b do not include the gas supply 1728, the valve 1730, and / or the cable 1732.

[0140] Figure 18 is a flowchart depicting example machine-readable instructions 1800 that may be executed by an electrode preheat control circuit 322 and / or a welding control circuit 1504 to be based on a user interface (e.g., Figure 13The user input of the user interface 1300 is used to control the preheating of the welding electrode (e.g., the electrode wire 114 in FIG. 4). Example instructions 1800 are described below with reference to the electrode preheating control circuit 322. However, the instructions 1800 can also be implemented partially or fully by the welding control circuit 1504.

[0141] In block 1802, the electrode preheating control circuit 322 initializes the welding power supply 302a and the preheating power supply 302b. In block 1804, the electrode preheating control circuit 322 sets the welding power and the preheating power to their respective default levels.

[0142] In block 1806, the electrode preheating control circuit 322 displays on the display device (e.g., indicators 1304, 1306) of the user interface 1300 the preheating level within the preheating range, the welding penetration level within the welding penetration range, the preheating heat input level, the total preheating and welding heat input level, the preheating voltage, the preheating current, and / or the enthalpy. The information displayed is based on the currently selected preheating power level, welding power level, and / or welding penetration level.

[0143] In block 1808, the electrode preheating control circuit 322 determines whether a user input has been received that includes a change to the preheating power, welding power, and / or welding penetration. If a user input has been received (block 1808), then in block 1810, the electrode preheating control circuit 322 sets the preheating power and / or welding power based on the user input.

[0144] If no user input has been received (block 1808), then the electrode preheating control circuit 322 determines whether the welding arc has started (block 1812). In some examples, the arc can be replaced by another high-intensity energy source such as a laser.

[0145] If the arc has started (block 1812), then in block 1814, the electrode preheating control circuit 322 controls the delivery of the preheating power through the first portion of the welding-type electrode based on the user input. For example, the electrode preheating control circuit 322 can control the power supply 302b to supply the preheating power to the electrode wire 114 via the contact tips 308, 318 based on the preheating power level selected by the user. In block 1816, the electrode preheating control circuit 322 controls the delivery of the welding power to the welding-type electrode based on the preheating power. For example, the effect of the preheating power can be determined from a feedback loop for the welding-type power, and / or the welding-type power level can be determined based on the selected preheating power level.

[0146] At block 1818, the electrode preheat control circuit 322 determines whether the arc is extinguished. If the arc is not extinguished (block 1818), control returns to block 1814 to continue controlling the preheat power and the welding power. For example, the electrode preheat control circuit 322 may determine whether the trigger of the torch has been released to stop welding. If the arc has been extinguished (block 1818), if the arc has not yet started (block 1812), and / or after the preheat power and / or the welding power have been set based on user input (block 1810), then control returns to block 1806.

[0147] As used herein, the terms "circuit" and "circuitry" refer to physical electronic components (i.e., hardware) and any software and / or firmware ("code") that can configure the hardware, be executed by the hardware, and / or otherwise be associated with the hardware. As used herein, for example, a particular processor and memory may include a first "circuit" when executing a first one or more lines of code, and may include a second "circuit" when executing a second one or more lines of code. As used herein, "and / or" means any one or more of the items in a list joined by "and / or". For example, "x and / or y" represents any element in the three-element set {(x), (y), (x, y)}. In other words, "x and / or y" means "one or both of x and y". As another example, "x, y and / or z" represents any element in the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}. In other words, "x, y and / or z" means "one or more of x, y and z". As used herein, the term "exemplary" means serving as a non-limiting example, instance or illustration. As used herein, the terms "such as" and "for example" list one or more non-limiting examples, instances or illustrations. As used herein, a circuit system is "operable" to perform a function as long as the circuit system includes the hardware and code (if necessary) required to perform the function, whether or not the execution of the function is disabled or not enabled (e.g., by user-configurable settings, factory trimming, etc.).

[0148] The method and / or system of the present invention can be implemented in hardware, software, or a combination of hardware and software. The method and / or system of the present invention can be implemented in a centralized manner in at least one computing system, or in a distributed manner, where different elements are distributed throughout several interconnected computing systems. Any type of computing system or other device adapted to execute the methods described herein is suitable. A typical combination of hardware and software can be a general-purpose computing system having a program or other code that, when loaded and executed, controls the computing system to cause it to execute the methods described herein. Another typical implementation can include a dedicated integrated circuit or chip. Some implementations can include a non-transitory machine-readable (e.g., computer-readable) medium (e.g., a flash drive, an optical disc, a magnetic storage disk, or the like) having one or more lines of code stored thereon, the code being executable by a machine, thereby causing the machine to execute the processes as described herein.

[0149] Although the methods and / or systems of the present invention have been described with reference to certain embodiments, those skilled in the art should understand that various changes can be made and equivalents can be substituted without departing from the scope of the methods and / or systems of the present invention. In addition, many modifications can be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the scope of the present disclosure. For example, the systems, blocks, and / or other components of the disclosed examples can be combined, divided, rearranged, and / or otherwise modified. Therefore, the methods and / or systems of the present invention are not limited to the particular embodiments disclosed. Instead, the methods and / or systems of the present invention will include all embodiments that literally and under the doctrine of equivalents fall within the scope of the appended claims.

[0150] All documents cited herein, including journal articles or abstracts, published or corresponding U.S. or foreign patent applications, issued patents or foreign patents, or any other documents, are hereby incorporated by reference in their entirety, including all data, tables, figures, and text presented in the cited documents.

Claims

1. A consumable electrode feed welding type system, comprising: A welding type power source configured to provide welding type power to a welding type circuit, the welding type circuit including a welding type electrode and a first contact end of a torch; An electrode preheating circuit configured to provide preheating power through a first portion of the welding type electrode via a second contact end of the torch; And An electrode preheating control circuit configured to control the preheating power based on a user input specifying the preheating power, wherein the user input specifies the preheating power as a ratio based on 1) one of preheating wattage, voltage of the preheating power, current of the preheating power, or impedance of the first portion of the welding type electrode, and 2) one of welding type wattage, voltage of the welding type power, current of the welding type power, or arc impedance.

2. The system according to claim 1, further comprising a user interface configured to receive the user input.

3. The system according to claim 2, wherein the electrode preheating control circuit is configured to control the welding type power based on the user input.

4. The system according to claim 2, wherein the user interface is configured to: Display a value representing at least one of the voltage of the preheating power, the current of the preheating power, the preheating wattage, the total energy of the preheating power and the welding type power, or the heat input efficiency; and Update the value in response to the user input; or The user interface is configured to: Display the value within an allowable selection range of a reference value, the value representing at least one of the preheating power or the welding type power; and Update the value in response to a selection of the preheating power.

5. The system according to claim 2, wherein the user input selects a voltage balance, wattage balance, current balance, heat balance, or enthalpy balance between the electrode preheating circuit and the welding type circuit.

6. The system according to claim 1, wherein the electrode preheating circuit is configured to provide preheating power via the second contact end and via at least one of the first contact end or the third contact end.

7. The system according to claim 1, further comprising a penetration sensor configured to detect welding penetration, and the electrode preheating control circuit is configured to control the preheating power and the welding type power to maintain the amount of welding penetration within a threshold range.

8. The system according to claim 1, further comprising a user interface to facilitate receiving a selection of wire deposition rate, and the electrode preheating control circuit is configured to control the preheating power based on the selection.

9. The system according to claim 8, wherein the electrode preheating control circuit is configured to: Increase the preheating power and increase the wire feeding speed of the electrode in response to an increase in the selected wire deposition rate; and Decrease the preheating power and decrease the wire feeding speed of the electrode in response to a decrease in the selected wire deposition rate.

10. The system according to claim 1, further comprising a display device for facilitating: displaying the balance between the preheat power and the welding-type power based on the user input; displaying the total heat input of the preheat power and the welding-type power; and updating the display of the balance and the total heat input in response to a change in the user input.

11. The system according to claim 1, wherein the electrode preheat control circuit is configured to control the preheat power based on at least one of a target total heat input for welding, a travel speed, a target bead width, or a target penetration depth.

12. A welding method, comprising: determining, by a control circuit based on user input, a target preheat power level, the user input specifying at least one of a target ratio between the preheat power and the welding-type power, or a target welding penetration depth; controlling, by the control circuit based on the user input, the delivery of the preheat power, the preheat power being delivered through a first portion of a welding-type electrode via a first contact tip of a torch; controlling, by the control circuit based on the preheat power, the delivery of welding power to the welding-type electrode via a second contact tip; and controlling a user interface device to display at least one of the voltage of the preheat power, the current of the preheat power, preheat wattage, the heat input of the preheat power, the heat input of the welding-type power, or the total heat input of the preheat power and the welding-type power.

13. A consumable electrode feed welding-type system, comprising: a welding-type power source configured to provide welding-type power to a welding-type circuit, the welding-type circuit including a welding-type electrode and a first contact tip of a torch; an electrode preheat circuit configured to provide preheat power through a first portion of the welding-type electrode via a second contact tip of the torch; an electrode preheat control circuit configured to control the preheat power based on user input specifying the preheat power; and a user interface configured to receive a selection of a wire deposition rate; wherein the electrode preheat control circuit is configured to: increase the preheat power and increase the wire feed speed of the electrode in response to an increase in the selected wire deposition rate; and decrease the preheat power and decrease the wire feed speed of the electrode in response to a decrease in the selected wire deposition rate; and a display device configured to: display the balance between the preheat power and the welding-type power based on the user input; display the total heat input of the preheat power and the welding-type power; and update the display of the balance and the total heat input in response to a change in the user input.

14. The system according to claim 13, wherein the user interface is configured to receive a selection of the preheat power, and the electrode preheat control circuit is configured to control the preheat power based on the selection; or The user interface is further configured to receive a selection of at least one of: preheat current, preheat voltage, preheat wattage, impedance, electrode temperature, power balance between the preheat wattage and the arc wattage, total heat input to the weld, preheat enthalpy, workpiece thickness, or wire diameter of the consumable welding-type electrode, and the electrode preheat control circuit is configured to control the preheat power based on the selection.

15. A consumable electrode feed welding-type system, comprising: A welding-type power source configured to provide welding-type power to a welding-type circuit based on a first control loop, the welding-type circuit including a welding-type electrode and a first contact end of a torch; An electrode preheat circuit configured to provide preheat power through a first portion of the welding-type electrode via a second contact end of the torch; And An electrode preheat control circuit configured to control the preheat power based on a second control loop having a user input that specifies at least one of a target heat input, a target preheat power level, a target ratio between the preheat power and the welding-type power, or a target arc penetration depth, the first control loop being responsive to the preheat power; and A display device configured to: Display the balance between the preheat power and the welding-type power; Display the total heat input of the preheat power and the welding-type power; and Update the display of the balance and the total heat input in response to changes in the preheat power and the welding-type power.

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