Gas metal arc welding-principle of operation, Mechanical Engineering

GAS METAL ARC WELDING-PRINCIPLE OF OPERATION

Gas Metal Arc Welding (GMAW) is one of the arc welding processes in which an electric arc is formed and maintained between a continuously fed filler metal electrode wire and the weld pool. In the arc heat, the electrode wire is melted and the molten metal (droplets) is transferred across the arc into the weld pool. The arc and the weld pool is shielded from the atmospheric contamination by an externally supplied shielding gas. The shielding gas can be Argon, CO2 or Argon + CO2 gas mixture depending on the type of base metal being welded. Generally for welding of non ferrous metals argon is used as the shield gas and then the process is called as Metal Inert Gas (MIG) welding.

 

For welding of ferrous metals, CO2 or Argon + CO2 gas mixture is used and then the process is called as Metal Active Gas (MAG) welding. The process is found to provide a stable arc and good process control when a direct current (DC) power source is employed with electrode positive (DCEP) polarity. The DCEP provides stable arc, greater heat input to the cathodic base metal for good penetration and a fluid weld pool. Equipment required for GMAW is shown. The system comprises of a DC power source with flat characteristics, wire feed unit, welding gun, cable assembly and gas cylinder. The wire electrode is fed continuously into the arc by the wire feed unit at a speed preset by the operator. The wire feed rate can be varied generally from 1 m / min. to 20 m / min. For a given wire material and diameter, the arc current is determined by the wire feed rate. The required voltage is selected by adjusting the voltage control knobs provided at the power source.

 

1255_gas arc welding2.jpg

Posted Date: 9/17/2012 12:47:34 AM | Location : United States







Related Discussions:- Gas metal arc welding-principle of operation, Assignment Help, Ask Question on Gas metal arc welding-principle of operation, Get Answer, Expert's Help, Gas metal arc welding-principle of operation Discussions

Write discussion on Gas metal arc welding-principle of operation
Your posts are moderated
Related Questions
Principal Planes and Principal Stresses: Define the Principal Planes and Principal Stresses. Sol.: When an element in strained body is under action of plane stresses, it i

Displacement or Swept Volume ( V s ) : The nominal volume swept by the working piston when travelling from one dead centre to the other is called the displacement volume. It is e

Need of a spectrophotometer: The specific instructions will differ with other models, but the principles remain. 1. The instrument must have been warm for at least 15 min.

Consider radar with a PRF of 5 kHz. What is the maximum unambiguous range R ua of this radar, in km?  If a target is located at a range of 50 miles, how many pulses will the r

analyze a six bar linkage to get the position, velocity and acceleration

Define Essentials of Milling Fixture? Strength of withstand heavy forces. Thrust should be directed towards a strong, solid structure. Cutter setting piece should b

Polygon law of forces

explain working and construction of locomotive boilers

Laws of solid friction: Sol.: The friction which exists between two surfaces that are not lubricated is called as solid friction. The two Surfaces can be at rest or one of t

Evaluate the normal and tangential stresses: Q. 20: At the point in stressed body, the principal stresses are σ x = 80 kN/m 2 and σ y = 40  kN/m 2 . Determine the norma