© COPYRIGHT 1998 THE ESAB GROUP, INC. LESSON II 2.7 ELECTROSLAG AND ELECTROGAS WELDING Electroslag Welding (ESW) and Electrogas Welding (EGW) comprise only a minor portion of all welding done in the country, but they are uniquely adapted to certain applications, primarily the joining of very thick materials.  The joining of a 12 inch material along a 40 foot line is not an uncommon application for the Electroslag process. 2.7.1 Electroslag Welding (See Figure 21) is technically not an arc welding process, although it utilizes a current carrying consumable electrode.  The only time there is an arc between the electrode and the work piece is when current is initially charged through the electrode.  This initial charge heats a layer of loose flux that becomes molten and extinguishes the arc. 2.7.2 Flux - The flux used in ESW is high in electrical resistance.  As current is applied, enough heat is generated from this resistance to keep the flux, base metal, and electrode in a molten state.  This axis of the weld joint is on a vertical plane.  The two pieces of metal, usually of the same thickness, are positioned so that there is an opening between them.  One or more electrodes are fed into the opening through a welding bead that travels vertically as the joint is filled.  To contain the molten puddle, water cooled copper shoes or dams are placed on the sides of the vertical cavity.  As the weld joint solidifies, the dams move vertically so as to always remain in contact with the molten puddle. 2.7.3 Process - A variation of ESW is the consumable guide method.  The process is the same with this method except that the guide tube that feeds the electrode to the molten pool is WATER  INLET/OUTLET COPPER  SHOE BASE METAL SOLIDIFIED  METAL WELD  POOL MOLTEN  FLUX GUIDE TUBE (CONSUMABLE  GUIDE  METHOD) ELECTRODE ELECTROSLAG  WELDING FIGURE 21
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Lesson 1
The Basics of Arc Welding
Lesson 2
Common Electric
Arc Welding Processes
Lesson 3
Covered Electrodes for Welding
Mild Steels
Lesson 4
Covered Electrodes for Welding Low Alloy Steels
Lesson 5
Welding Filler Metals for Stainless Steels
Lesson 6
Carbon & Low Alloy
Steel Filler Metals -
GMAW,GTAW,SAW
Lesson 7
Flux Cored Arc Electrodes Carbon Low Alloy Steels
Lesson 8
Hardsurfacing Electrodes
Lesson 9
Estimating & Comparing Weld Metal Costs
Lesson 10
Reliability of Welding Filler Metals