Welding Metallurgy

Learning Outcomes of the Course Unit

1) Explain the temperature distribution in welds and the microstructure formed as a result for a single pass weld versus a multi-pass weld.
2) Comment of the effects of heat input, cooling rate and multi -pass operation on weld metal solidification and the microstructure formed for a single pass weld versus a multi-pass weld.
3) Explain the effects of the weld protection, the type of consumables on the microstructure of the weld metal and on it properties for a single pass weld versus a multi-pass weld.
4) Explain areas of HAZ, the reasons for grain, size and microstructure changes and their effects on properties for a single pass weld versus a multi-pass weld.
5) Discuss the various aspects of weldability.
6) Deduce the microstructural and weldability changes induced by dilution.
7) Explain the concept and use of carbon equivalent.
8) Explain the principle and use of TTT diagrams (isothermal, continuous cooling, TTT diagrams for welding).
9) Recognize the structure of welds and HAZ for given thermal cycles and composition.
10) Explain in detail the effects of a multi pass welding on the structure, the mechanical properties.
11) Discuss the factors affecting cold cracking.
12) Identify optimal heat input and appropriate pre-heat for given materials, conditions and applications utilising Codes and standards as required.