This course is designated for Professional Development of Welding Educators teaching secondary and post-secondary welding programs. “Welding Metallurgy and Weldability of Commercial Alloys” course covers the concepts and fundamentals of atomic structure, grain structure, heat flow, phase transformations, welding metallurgy, and the weldability of ferrous and non-ferrous commercial alloys. Laboratory work consists of welding metallurgy investigation on the welded samples and weldability testing for specific applications.