Systems, Methods, and Apparatus to Preheat Welding Wire

Abstract

A contact tip assembly with a preheating tip comprises a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch; an electrode preheating circuit configured to provide preheating current through a first portion of the electrode via a second contact tip of the welding torch; and a preheat controller to: monitor a voltage drop across a second portion of the electrode; adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the electrode comprising at least part of the first portion of the electrode; and control the preheating current based on a hydrogen reduction goal and based on stored parameters associated with a type of the electrode, a chemistry of the electrode, or a wire size.

What is claimed is: 
     
         1 . A consumable electrode-fed welding-type system, comprising:
 a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch;   an electrode preheating circuit configured to provide preheating current through a first portion of the welding-type electrode via a second contact tip of the welding torch; and   a preheat controller to:
 monitor a voltage drop across a second portion of the welding-type electrode; 
 adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the welding-type electrode comprising at least part of the first portion of the welding-type electrode; and 
 control the preheating current based on a hydrogen reduction goal and based on stored parameters associated with a type of the welding-type electrode, a chemistry of the welding-type electrode, or a wire size. 
   
     
     
         2 . The welding-type system as defined in  claim 1 , wherein the first contact tip is configured to conduct the preheating current, the first portion of the welding-type electrode being between the first and second contact tips of the welding torch. 
     
     
         3 . The welding-type system as defined in  claim 1 , wherein the first contact tip is positioned closer to an arc end of the welding-type electrode than the second contact tip. 
     
     
         4 . The welding-type system as defined in  claim 1 , wherein the second contact tip is positioned closer to an arc end of the welding-type electrode than the first contact tip. 
     
     
         5 . The welding-type system as defined in  claim 1 , wherein the electrode preheating circuit is configured to conduct the preheating current via a third contact tip of the welding torch. 
     
     
         6 . The welding-type system as defined in  claim 5 , wherein the third contact tip contacts the welding-type electrode such that the welding-type current and the preheating current are superimposed on the first portion of the welding-type electrode. 
     
     
         7 . The welding-type system as defined in  claim 5 , wherein the third contact tip contacts the welding-type electrode such that the welding-type current does not flow through the first portion of the welding-type electrode that conducts the preheating current. 
     
     
         8 . The welding-type system as defined in  claim 1 , wherein the preheat controller is configured to control the electrode preheating circuit to increase the preheating current of the first portion of the welding-type electrode and control the welding-type power source to decrease the welding-type current based on the increase in the preheating current. 
     
     
         9 . The welding-type system as defined in  claim 1 , wherein the preheat controller is configured to control the electrode preheating circuit to preheat the first portion of the welding-type electrode to a temperature based on a feed speed of the welding-type electrode. 
     
     
         10 . The welding-type system as defined in  claim 1 , wherein the preheat controller is configured to access a look-up table to retrieve preheat parameters based on at least one of the type of the welding-type electrode, the size of the welding-type electrode, or a feed rate. 
     
     
         11 . The welding-type system as defined in  claim 1 , wherein the preheat controller is configured to use predetermined preheat parameters. 
     
     
         12 . The welding-type system as defined in  claim 1 , further comprising an enthalpy measurement circuit to determine an enthalpy applied to an electrode based on at least one of a measured arc voltage, a measured welding-type current, or a measured preheating current, or the voltage drop across the second portion of the welding-type electrode, the preheat controller to control the preheating current based on the determined enthalpy and a target enthalpy to be applied to the electrode. 
     
     
         13 . The welding-type system as defined in  claim 1 , wherein the welding-type current is controlled according to an advanced waveform. 
     
     
         14 . The welding-type system as defined in  claim 1 , wherein the electrode preheating circuit is configured to heat the welding-type electrode and deposit heated filler material on a workpiece in one or more deposition passes without an electrical arc, the welding-type power source configured to perform one or more passes on the workpiece with the electrical arc. 
     
     
         15 . The welding-type system as defined in  claim 1 , wherein the electrode preheating circuit comprises a second power source configured to provide the preheating current. 
     
     
         16 . The welding-type system as defined in  claim 1 , further comprising:
 a preheat monitor to:
 monitor a preheating signal generated by the electrode preheating circuit; and 
 based on the preheating signal, identify an anomaly in the preheating signal based on at least one of a threshold signal level, a time derivative of the preheating signal, an integral of the preheating signal, a statistical analysis of the preheating signal, or a stability over a time period of the preheating signal, the preheating signal comprising at least one of a preheat voltage, a preheat current, a preheat power, or a preheat circuit impedance, the statistical analysis comprising at least one of a mean of the preheating signal, a standard deviation of the preheating signal, or a root mean squared value of the preheating signal. 
   
     
     
         17 . The welding-type system as defined in  claim 1 , wherein at least one of the first contact tip or the second contact tip are cooled via liquid cooling lines. 
     
     
         18 . The welding-type system as defined in  claim 1 , where the welding-type system is performing at least one of a gas metal arc welding process or a submerged arc welding process. 
     
     
         19 . The welding-type system as defined in  claim 1 , wherein the welding-type current is alternating current, the preheat controller controls the preheating current to be alternating current, and the preheat controller controls the preheating current to be synchronous with the welding-type current such that corresponding polarities of the welding-type current and the preheating current result in reducing a net current at the first contact tip. 
     
     
         20 . The welding-type system as defined in  claim 1 , further comprising a control circuit configured to:
 detect that the voltage drop across the second portion of the welding-type electrode is outside of an expected range; and   in response to the detecting, reduce or stop at least one of the preheating current or the welding-type current.   
     
     
         21 . The welding-type system as defined in  claim 1 , wherein the preheat controller is configured to control the preheat current based on a distance between the first and second contact tips. 
     
     
         22 . A consumable electrode-fed welding-type system, comprising:
 a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch;   an electrode preheating circuit configured to provide preheating current through a first portion of the welding-type electrode via a second contact tip of the welding torch;   a hydrogen sensor configured to measure hydrogen at least one of: 1) in the welding-type electrode or 2) proximate the welding-type electrode; and   a preheat controller configured to:
 monitor a voltage drop across a second portion of the welding-type electrode; 
 adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the welding-type electrode comprising at least part of the first portion of the welding-type electrode; and 
 control the preheating current based on a hydrogen reduction goal and based on a hydrogen measurement from the hydrogen sensor. 
   
     
     
         23 . The welding-type system as defined in  claim 22 , wherein the hydrogen sensor comprises at least one of a palladium-based sensor or a titanium-based sensor. 
     
     
         24 . A consumable electrode-fed welding-type system, comprising:
 a welding-type power source configured to provide welding-type current to a welding-type circuit, the welding-type circuit comprising a welding-type electrode and a first contact tip of a welding torch;   an electrode preheating circuit configured to provide preheating current through a first portion of the welding-type electrode via a second contact tip of the welding torch;   a moisture sensor configured to measure moisture at least one of: 1) in the welding-type electrode or 2) proximate the welding-type electrode; and   a preheat controller to:
 monitor a voltage drop across a second portion of the welding-type electrode; 
 adjust at least one of the welding-type current or the preheating current based on the voltage drop, the second portion of the welding-type electrode comprising at least part of the first portion of the welding-type electrode; and 
 control the preheating current based on a hydrogen reduction goal and based on a moisture measurement from the moisture sensor.