Electrode assembly for arc welding

Abstract

The disclosed technology generally relates to welding technologies and more particularly to electrode assemblies for arc welding, e.g., submerged arc welding. In one aspect, an electrode assembly for submerged arc welding comprises a contact tip portion and an extension portion arranged serially and configured to feed a consumable electrode therethrough. During welding, the contact tip portion is disposed to be distal to an arcing tip of the consumable electrode and the extension portion is disposed to be proximal to the arcing tip of the consumable electrode. The extension portion is configured to electrically insulate the consumable electrode from a work piece during welding with a solid insulating material surrounding the consumable electrode.

1 . An electrode assembly for submerged arc welding (SAW), comprising:
 a head portion and an extension portion arranged serially and configured to feed a consumable electrode therethrough, wherein during welding, the head portion is disposed to be distal to an arcing tip of the consumable electrode and the extension portion is disposed to be proximal to the arcing tip of the consumable electrode,   wherein the extension portion is elongated in a wire feed direction and configured to electrically insulate the consumable electrode from a work piece during welding with an insulating sleeve surrounding the consumable electrode, and   wherein the electrode assembly is configured such that, during welding with the consumable electrode inserted therethrough, a ratio between an electrical stick-out distance, measured between a contact tip portion disposed at an end of the head portion and the arcing tip of the consumable electrode, and a diameter of the consumable electrode exceeds 30.   
     
     
         2 . The electrode assembly of  claim 1 , wherein the extension portion has an outer surface formed of a substantially non-magnetic material surrounding the insulating sleeve. 
     
     
         3 . The electrode assembly of  claim 2 , wherein the insulating sleeve is formed of a ceramic material that is enveloped by a substantially non-magnetic steel-based envelope forming the outer surface of the extension portion. 
     
     
         4 . The electrode assembly of  claim 3 , wherein the insulating sleeve and the non-magnetic steel-based envelope are held together by an adhesive layer. 
     
     
         5 . (canceled) 
     
     
         6 . The electrode assembly of  claim 1 , wherein the extension portion has a length greater than 100 mm and wherein the electrode assembly is configured for the electrical stick-out distance exceeding 125 mm. 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . The electrode assembly of  claim 6 , wherein the extension portion has an elongated shape such that, when fully inserted into a triangular trench having a depth exceeding 4 inches and having an angle of an apex that is less than 16 degrees such that the tip of the consumable electrode contacts the apex of the triangular trench, no part of the extension portion contacts a sidewall of the triangular trench. 
     
     
         10 . The electrode assembly of  claim 6 , wherein the electrode assembly is configured to achieve a deposition rate per current exceeding 0.05 lbs./hr./A during welding. 
     
     
         11 . The electrode assembly of  claim 6 , wherein the electrode assembly is configured to achieve a deposition rate exceeding 35 lbs./hr. at a current less than 900 A during welding. 
     
     
         12 . The electrode assembly of  claim 6 , wherein the electrode assembly is configured to drop at least 5% of a total voltage drop across a distance between the head portion and the arcing tip of the consumable electrode. 
     
     
         13 . The electrode assembly of  claim 6 , wherein the electrode assembly is configured to heat the consumable electrode by Joule heating within the extension portion to a temperature up to 800° C. 
     
     
         14 . (canceled) 
     
     
         15 . The electrode assembly of  claim 1  wherein the insulating sleeve is formed of a ceramic material selected from the group consisting of silicon nitride, magnesia-stabilized zirconia, yttria-stabilized zirconia, silicon carbide, magnesium oxide, alumina, or a zirconia-toughened alumina. 
     
     
         16 . The electrode assembly of  claim 1 , further comprising:
 a flux delivery system fixedly attached to the extension portion and configured such that the flux delivery system does not limit a lower limit of a width of a groove of a workpiece the extension portion is capable of being inserted into.   
     
     
         17 . An electrode assembly for submerged arc welding, comprising:
 a head portion; and   an extension portion arranged serially with the head portion in a wire feed direction, wherein the head portion and the extension portion are configured to feed a consumable electrode therethrough, wherein the extension portion is configured to be disposed closer to an arcing tip of the consumable electrode relative to the head portion and comprises:
 an envelope formed of a nonmagnetic material; and 
 an insulating sleeve disposed within the envelope and comprising a solid insulating material configured to surround the consumable electrode. 
   
     
     
         18 . The electrode assembly of  claim 17  wherein:
 the extension portion comprises opposing first and second ends separated in the wire feed direction, 
 the head portion comprises a contact tip portion configured to apply a voltage and pass current to the consumable electrode and configured to be proximal to the first end of the extension portion and distal to the second end of the extension portion, 
 when the consumable electrode is fed through the electrode assembly, an arcing tip of the consumable electrode is configured to be proximal to the second end of the extension portion and distal to the first end of the extension portion, and 
 the extension portion is disposed between the arcing tip and the contact tip portion. 
 
     
     
         19 . The electrode assembly of  claim 18  wherein the electrode assembly is configured for an electrical stick-out distance, measured between a contact tip portion disposed at an end of the head portion and the arcing tip of the consumable electrode, exceeding 125 mm. 
     
     
         20 . The electrode assembly of  claim 19 , wherein the electrode assembly configured such that a ratio between an electrical stick-out distance, measured between a contact tip portion disposed at an end of the head portion and the arcing tip of the consumable electrode, and a diameter of the electrode exceeds 30. 
     
     
         21 . The electrode assembly of  claim 17 , wherein the solid insulating material comprises a ceramic material. 
     
     
         22 . The electrode assembly of  claim 17 , wherein the insulating sleeve is fixedly attached to the envelope by an adhesive layer that comprises a brazed metallic joint. 
     
     
         23 . (canceled) 
     
     
         24 . An extension portion configured for a submerged arc welding electrode assembly, the extension portion comprising:
 an envelope formed of a nonmagnetic material; and   an insulating sleeve disposed within the envelope and comprising a solid insulating material configured to surround a consumable electrode,   wherein the extension portion is configured to be arranged serially with a head portion of the electrode assembly and to receive the consumable electrode from the head portion.   
     
     
         25 . The extension portion of  claim 24 , wherein the extension portion has a length greater than 100 mm. 
     
     
         26 . The extension portion of  claim 24 , wherein the extension portion is configured for a diameter of the consumable electrode exceeding 3 mm. 
     
     
         27 . The extension portion of  claim 26 , wherein the extension portion is configured such that during welding with the consumable electrode inserted therethrough, a ratio between an electrical stick-out distance, measured between a contact tip portion disposed at an end of the head portion and an arcing tip of the consumable electrode, and the diameter of the electrode exceeds 30. 
     
     
         28 . The extension portion of  claim 24 , wherein the insulating sleeve is formed of a ceramic material. 
     
     
         29 . The extension portion of  claim 24 , wherein the envelope is formed of a substantially non-magnetic steel-based material. 
     
     
         30 . (canceled) 
     
     
         31 . The extension portion of  claim 24 , wherein the insulating sleeve and the envelope are held together by an adhesive layer. 
     
     
         32 . (canceled)