Mustafa Ebrahim

Effect of processing parameters on the quality of hot dip galvanizing of cold rolled steel: ---------------------------------------------- Metals play a very vital role in our daily life. Steel has always been the most favored and widely used material because of its excellent strength, formability, economics of production, and its ability to recycle indefinitely. The primary quality of steel, the physical and mechanical strength, is compromised when corrosion reaches a critical point. The service life of a structure depends on the rate of reaction between the steel and its environment. The rate of reactions depends on the nature and concentration of the corrosive agents present in the environment. Hence, most of the energies and research has been involved in reducing corrosion of steel. The most popular and most widely process used for corrosion protection of steel by hot dip galvanizing process. Although the science and technology of hot dip galvanizing have improved significantly over the years, it is still a challenge to produce high-quality coatings for decorative and constructional applications. Hot dip galvanizing layer completely covers the steel surface and protects it from the corrosive action of its environment corrosion by providing a thick, tough metallic zinc envelope. The galvanized coating provides outstanding abrasion resistance. There are some significant problems concerning the forming of galvanized sheet steels need to be solved. The two most significant problems are those of the coating effect in friction and coating damage during forming, depending on the flow and fracture behavior of the coating material. Characterization of the coating in terms of its microstructure would be a first step in understanding the forming characteristics of galvanized sheet steels. The formability of zinc layer is influenced by many factors such as chemical composition of the substrate, kind and quantity of alloying elements in zinc bath. Therefore, the objective of this thesis was to study the effect of operating conditions on the hot dip galvanizing process. Moreover, the influence of different kinds and quantities of alloying elements in zinc bath and silicon contents of steel composition has been studied. The mechanical and chemical properties of the galvanized layer have been investigated.