Introduction: Basic classification of welding processes, weldability, weld thermal cycle, metallurgy

of fusion welds, solidification mechanism and microstructural products in weld metal, epitaxial,

cellular and dendritic solidification, metallurgical changes in weld metal, phase transformation

during cooling of weld metal in carbon and low alloy steel, prediction of microstructures and

properties of weld metal. Heat affected zone, re-crystallization and grain growth of HAZ, gas metal

reaction, effects of alloying elements on welding of ferrous metals. (6 Hours)

Welding Arc: Arc efficiency, temperature distribution in the arc; arc forces, arc blow, electrical

characteristics of an arc, mechanism of arc initiation and maintenance, role of electrode polarity on

arc behaviour and arc stability, analysis of the arc. (5 Hours)

Coated Electrodes: Electrode coatings, classification of coatings of electrodes for SMAW, SAW

fluxes, role of flux ingradients and shielding gases, classification of solid and flux code wires,

 (5 Hours)

Fusion Welding reviews: Critical reviews of manual metal arc welding (MMAW) GTAW, GMAW,

FCAW and CO welding processes, plasma arc, submerged arc welding, electro gas and electro slag

welding, analysis of the process. (5 Hours)

Welding power sources: Arc welding power sources basic charters tics of power sources for various

arc welding processes, duty cycles, AC, DC welding power source, DC rectifiers, thyristor controlled

rectifiers, transistorised units, inverter systems. Arc length regulation in mechanised welding

processes, (5 Hours)

Metal Transfer and Melting Rate: Mechanism and types of metal transfer, forces affecting metal

transfer, modes of metal transfer, metal transfer in various welding processes, effective of polarity on

metal transfer and melting rate. (5 Hours)

Solid State welding: Theory and mechanism of solid sate welding. Techniques and scope of friction

welding, diffusion welding, cold pressure welding and ultrasonic welding. High energy rate welding.

Analysis of the Process. (5 Hours)

Welding Techniques using Radiation energy: Technique, scope and application of the electron beam

and laser welding processes.