How the strength of steel can be bolstered through the use of some clever chemistry?
Steel has been around for millennia, ever since it was discovered that introducing carbon to the forge produced a much harder and durable metal than iron. Like iron though, it’s still susceptible to the elements: exposed to moisture and oxygen in the air, it’s prone to corrosion and rust. So, in the 18th and 19th centuries, heavy industry led to the process of curing steel – otherwise known as galvanizing.
Hot-dipping is the most common method of galvanization. It involves a final stage of dipping steel into a bath of molten zinc at around 460 degrees Celsius (860 degrees Fahrenheit). The zinc bonds with the steel, forming iron-zinc alloys which, in turn, forms zinc oxide on the surface. As it’s the zinc that’s effectively rusting and not the iron, the zinc oxide layer helps protect the steel, increasing its life span from around five years to anything up to 70 years.