Electroless Nickel Phosphorus Coatings to Mitigate the Corrosion of Construction Steel

Abstract

Reinforced concrete is widely used in structures and construction, but its durability is limited due to corrosion of the embedded steel rebars. Thus, mitigation of corrosion of construction steel rebars is an important area of research. The present work reports the ability of electroless nickel phosphorus coating for corrosion protection of Fe-600-grade steel rebars used for construction purposes in chloride and sulphate environment. The coating deposited on Fe-600 rebar was Ni-P and was subjected to electrochemical tests in 3.5% NaCl and 0.5M H2SO4. Severe corrosion pitting and cracking were observed for the uncoated rebar while Ni-P coating showed nobler corrosion potential and low corrosion current density in the corrosive environments.