Despite its high susceptibility to rusting, steel remains one of the most widely used alloys in the industrial world. One of the main reasons for the widespread use of steel in industrial settings is that steel manufacturers have devised ways to make their products more rust-resistant, thus maximising product durability.
Here are three coating methods or systems steel fabricators use to protect steel against the rusting process.
Galvanising is one of the most widely used methods of preventing rusting of steel. It involves applying a zinc coating to the surface of bare steel to stop it from corroding.
Zinc is more reactive than iron and thus acts as a sacrificial anode. Provided the substrate steel (made up of iron and carbon) remains in contact with the zinc, corrosion will affect the zinc and spare the steel.
As a result, this kind of protection is sometimes referred to as sacrificial protection.
Ever wondered why stainless steel does not rust despite not having a protective coating applied to its surface. Unlike other types of steel that require a special coating to prevent rusting of the substrate alloy, stainless steel derives its rust resistance from a process called chromising.
Chromising is an alloying process that involves adding a minimum percentage of chromium to steel (the base material) to make it more rust-resistant. The process is carried out at elevated temperatures, creating steel that does not corrode in the presence of water and oxygen.
Although other high-temperature alloys can be diffused with chromium, chromising is predominantly used for the manufacture of stainless steel.
While powder coating and conventional wet paint application serve similar purposes when used on steel, the former is generally preferred over the latter due to its superior performance and durability.
Usually applied electrostatically as a dry powder, powder coatings generally have greater thicknesses than liquid paint coatings. As a result, they provide a higher level of resistance to rust.
Because conventional paint can crack or peel easily, it is not usually used alone but in combination with other rust-proofing systems.
The quality of steel products is usually based on many performance parameters, including their ability to resist rusting. Depending on the intended applications, different steel supplies may require different treatments or surface coatings to prevent rust attacks.
The best way to determine which steel products are suitable for your project is to consult steelwork professionals that serve clients in your area.