An expert seminar for South African civil engineers, consulting engineers, marine engineers and architects was hosted by the International Zinc Association (IZA) on 13 June in Umhlanga in KwaZulu-Natal and Cape Town in the Western Cape on 21 June 2024.

Attended by 30 consulting engineers, the seminar focused on the critical role of zinc coatings and galvanized steel, explains IZA Africa Director Simon Norton. In addition to looking in-depth at the role of zinc in corrosion protection, the seminar also delved into topics such as hot dip galvanizing, continuous galvanizing, zinc thermal spray, zinc rich paints and zinc thermal diffusion.

Zinc thermal spraying steel to ensure the corrosion protection of steel

An expert consultant in corrosion and failure investigation, Norton presented the seminars in conjunction with Terence Smith, formerly technical director of the Hot Dip Galvanizing Association of South Africa (HDGASA) and now an independent expert consultant in galvanizing.

The intensive one-day seminar provided engineers and architects with expert knowledge concerning the use of zinc as an anti-corrosion protective coating on steel. All delegates received IZA literature to accompany the seminar in the form of the IZA book ‘Essentials of Galvanizing’ published in 2020 and the new IZA book published in May 2024 entitled ‘Expert Guide to Galvanizing’.

When applied to steel, zinc acts as a sacrificial anode that corrodes preferentially, sacrificing itself to protect the underlying metal. Zinc corrodes instead of the base metal to prevent rust and degradation. Its most notable property is its ability to protect metals from corrosion through galvanic action.

As the zinc coating reacts, it forms a dense, adherent layer of byproducts known as a zinc patina which transforms the galvanized item from a shiny silver look to a matt dark grey appearance. The galvanized or zinc coated steel can then be overcoated with an organic coating, known as duplex coating of steel and a powerful means to effect long life to steel structures.

The zinc coating also acts as an additional barrier between the steel and the environment, slowing down the rate of corrosion considerably compared to unprotected exposed steel materials. As zinc corrodes, an oxy/hydroxy carbonate forms on protective zinc coatings. This self-healing process creates an impervious, coating resistant to the atmospheric environment.

IZA Africa imminently expects to offer its new zinc and corrosion protection seminar in Johannesburg and elsewhere if so requested. Consulting engineering firms are encouraged to contact IZA Africa about its experts presenting zinc in corrosion protection in the convenience of their own offices.