Unit 1

Overview of welding processes and their classification, types of joints, edge preparation, weld symbols, weld nomenclature, bead geometry, power density, heat sources – Gaussian distribution of heat flux, welding techniques – linear and orbital. Arc characteristics. Voltage-current characteristics. Types of welding manipulators and their applications.
Advanced welding processes: submerged arc, TIG, MIG, electro-slag, ultrasonic, electron beam and laser beam welding. Case studies and applications – industrial, automotive and aerospace.

Unit 2

Thermal modeling and simulation of welding processes – governing heat transfer equations and boundary conditions for various types of welding processes. Estimation of cooling rates. Prediction of mechanical properties, micro/macro-structures of weldments and heat-affected zone. Prediction of weld defects such a crack, segregation, lack of fusion. Modeling and simulation of pulsed arc processes. Use of softwares for simulation.
Solidification behaviour of fusion weld: structural zones, epitaxial growth, weld pool shape and columnar grain structures. Weldability of metals- steels, stainless steels, aluminium, copper, nickel and titanium alloys.

Unit 3

Microstructures of weldment.Segregation of alloying elements.Impact of micro/macro-structures and segregation on mechanical properties.Pre- and post-treatment. Effects of heat flow on residual stresses and distortion. Weldability tests.
Welding defects – causes and remedies.Methods of testing weldments – mechanical, pressure and leak testing.Inspection methods – visual, penetrant, magnetic, ultrasonic, x-ray and gamma radiography.Use of imaging techniques for online monitoring.

Course Objectives

• Elucidate the concepts of continuity, mechanism, physics, and design elements in welding process
• Comprehend the characteristics of weldable materials and welding technologies
• Demonstrate the importance of modelling and simulation of welding process
• Develop intellectual skills for correlating the microstructural evolution with the defects and properties of weldments

Course Outcomes

• CO1: Describe welding processes, welding symbols, joint configurations, and heat source characteristics
• CO2: Formulate governing equations and boundary conditions to simulate the thermal phenomenon in the course of a welding process
• CO3: Evaluate the microstructural evolution on the properties of weldments
• CO4: Identify appropriate techniques for detecting the welding defects

CO – PO Mapping

Textbook(s)

• Khanna O. P. – ‘A Text Book on Welding Technology’ – Dhanpat Rai and Sons, New Delhi – 2013
• Parmar R. S. – ‘Welding Process and Technology’ – Khanna Publishers, Delhi – 1992

Reference(s)

• Little R. L. – ‘Welding and Welding Technology’ – Tata McGraw Hill Publishing Company Limited, New Delhi – 1989
• Grong O. – ‘Metallurgical Modelling of Welding’ – The Institute of Materials – 1997 – 2^nd Edition
• Kou S. – ‘Welding Metallurgy’ – John Wiley Publications, New York – 2003 – 22^nd Edition.

Evaluation Pattern