Chris Di Giovanni (M.Sc.)
The goal of Chris’ research is to determine the cause of cracking found in the welded joints of a steel platform structure after galvanizing, and to create a mitigation plan for the steel fabricator. A study on the effects of the pickling process prior to galvanizing and the potential effects of hydrogen in the steel has been completed and a fractography study has characterized the type of fracture. A finite element model has also been created to determine the thermal stresses induced in the structure by the galvanizing process, with a focus on the double dip procedure used. An in-depth study of the metallurgy and microstructure of the base material is ongoing as although the cracks initiated at the weld toe, they propagated in the base material. A bulk composition analysis shows unfavorable elements in a high weight percentage. Moving forward, the microstructure of the weld and base material will be studied further to look for signs of element segregation and inclusion composition. Tension tests at elevated temperatures will be carried out to look for signs of hot shortness and how the material behaves under load at high temperatures. The project is sponsored by Waiward Steel and Mitacs.
Cracking found in the corner joint propagating into the base material
Finite element model showing temperature gradient during hot dipping