Galvanising is the process by which a zinc coating is applied to a metal component, generally made of carbon steel, in order to protect it from corrosion that would otherwise occur when directly exposed to atmospheric conditions.
Galvanising can be carried out using different processes, the most common of which are:
Zinc is used as a coating material because it has a lower electrochemical nobility than carbon steel and therefore corrodes preferentially when exposed to the atmosphere. The corrosion of the zinc layer leads to the formation of bulky corrosion products that create a compact oxide layer, acting as an effective protective barrier against environmental agents.
However, when the zinc coating deteriorates or is damaged – for example due to mechanical actions such as impacts, cuts or abrasion, or due to prolonged exposure to particularly aggressive environmental conditions – the barrier effect is lost and corrosion begins to affect the base material.
In the case of carbon steel, this results in the formation of reddish-brown, powdery corrosion products (commonly referred to as rust). The progression of corrosion may lead, depending on several factors including environmental aggressiveness, to a reduction in material thickness and a consequent loss of mechanical properties, with potential safety risks related to the use of anchorage devices forming part of a fall protection system.
It is of fundamental importance to monitor the condition of anchorage devices and fall protection systems through periodic inspections carried out by competent and authorised personnel, in accordance with the intervals prescribed by the manufacturer.
Based on the inspection results and the extent of any detected corrosion phenomena, it may be necessary to replace corroded components.
