Low carbon steel (St37) is the most widely used construction material in many industries due to its excellent ductility and toughness, weldability and good mechanical workability. Nevertheless, it is vulnerable to corrosion, which is regarded as the deterioration of a metal material due to reaction with its environment. In accordance with the second law of thermodynamics, steel materials such as St37 tends to reverse back to its ore state as a result of chemical and electrochemical reactions. It is estimated that corrosion destroys one quarter of the worlds annual steel production. The most popular and most widely process used for corrosion protection of steel is galvanizing. Hot dip galvanized (HDG) zinc coatings are known for good workability and high corrosion resistance. This paper describes the corrosion behavior of St37 grade commercial hot-dip galvanized steel in 3.5% NaCl Solution. Electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) techniques were used respectively in this study. The obtained results show that the HDG approach provides an effective protection and shields the St37 steel against corrosion for a long time. However, over time, it is seen that the protective layer formed on the metal surface gradually desorbs, this results to the corrosion of the metal.
Anahtar Kelimeler: Corrosion, St37, Galvanization, HDG