Welding Metallurgy

This course focuses on understanding the metallurgical principles and concepts of welding processes. Students are required to be aware of the science and engineering behind welding phenomena especially in the domain of weld metal solidification, heat transfer, heat treatment processes, strengthening mechanisms, formation of heat affected zones etc. The course will be useful for engineering graduates as well as professionals working in the area of welding.

The course requires an introductory knowledge of basic manufacturing processes, material science and engineering. It broadly includes the following topics such as introduction to welding metallurgy, phase diagrams, phase transformation, heat treatment processes, metal strengthening approaches, heat flow and pressure distribution in welding, concept of solidification and heat affected zones in welding, residual stresses and distortion and solidification cracking.

Welding Metallurgy.
Distinct Zones in Fusion Welded Specimen.
Heat Affected Zone.
Properties of Heat Affect Zone.
Microstructural Products in Weldments.
Introduction to Preheat and Postweld Heat Treatment.
Preheat and Postweld Heat Treatment of Different Materials.
Residual Stresses in Welding.
Causes of Residual Stress Development in Welding.
Measurement of Residual Stresses in Weldments.
Controlling Residual Stresses in Weldments.
Introduction to Welding Distortion.
Types of Welding Distortions.
Angular Distortions in Welds.
Bowing, Buckling and Twisting in Welds.
Control of Distortion in Welds.
mod10lec46.
mod10lec47.
mod10lec48.
mod10lec49.
mod10lec50.
mod11lec51.
mod11lec52.
mod11lec53.
mod11lec54.
mod11lec55.
mod12lec56.
mod12lec57.
mod12lec58.
mod12lec59.
mod12lec60.
Introduction to welding metallurgy.
Overview of Welding Processes.
Introduction to phase diagrams.
Phase diagram of Iron Carbon system.
Phase diagram of non ferrous metals and alloys.
Phase Transformations.
Time Temperature Transformation Diagrams.
Continuous Cooling Transformation Diagrams.
Carbon Equivalent, Schaeffler Diagrams.
Problem solving on Phase Diagrams.
Introduction to strengthening mechanism in metals.
Solid solution strengthening and grain refinement.
Precipitation Hardening and Martensite Strengthening.
Strain Hardening and Strain Ageing.
Problem solving on strengthening mechanism in metals.
Introduction to Heat treatment Processes in Welding.
Hardening and Hardenability.
Martempering and Austempering.
Case Hardening methods.
Heat treatment of Non-Ferrous metals and alloys.
Heat Sources in Welding.
Heat Flow in Welding.
Temperature Distribution in Welding.
Effect of Welding Parameters.
Metallurgical effect of Heat Flow on Welding.
Principles of Solidification in Welding.
Solute redistribution during Solidification.
Constitutional Supercooling.
Microsegregation and Banding.
Grain Structure during Solidification in Welding.