Corrosion resistance of galvanized roofing sheets in acidic and rainwater environments

Olufunmilayo O Joseph; Olakunle O Joseph; Joseph O Dirisu; Ayinoluwa E Odedeji

doi:10.1016/j.heliyon.2021.e08647

Corrosion resistance of galvanized roofing sheets in acidic and rainwater environments

Heliyon. 2021 Dec 21;7(12):e08647. doi: 10.1016/j.heliyon.2021.e08647. eCollection 2021 Dec.

Authors

Olufunmilayo O Joseph¹, Olakunle O Joseph², Joseph O Dirisu¹, Ayinoluwa E Odedeji¹

Affiliations

¹ Department of Mechanical Engineering, Covenant University, Ota, Nigeria.
² Department of Mechanical Engineering, Federal Polytechnic, Ilaro, Ogun State, Nigeria.

Abstract

The galvanization of steel sheets for building roofs and construction of additional structures has been a valued solution to the challenges faced by the deterioration of roofing steel sheets in an unfavourable surroundings. This research was conducted on galvanized roofing sheets obtained from the open market in Nigeria. The samples were cut to a small size (5 cm by 4 cm) and immersed in sulfuric acid (H₂SO₄) and hydrochloric acid (HCl). As the control medium for the experiment, rainwater was used. The experiment was performed over 1200 hours; each sample was removed every 240 hours, thoroughly washed, dried, and weighed again. Based on the reacting media, variations in the weights of the samples were obtained. According to ASTM G1-03 standard practice, Corrosion rates were calculated for preparing, cleaning, and evaluating corrosion test specimens. Scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) was also carried out. Although some samples resisted corrosion, other samples corroded. It is predicted that the green-coated samples are more resistant to corrosion in rainwater and H₂SO₄ and thus more stable.

Keywords: Acid; Corrosion; Morphology; Rain water; Resistance; Roofing sheet.