The methods of corrosion protection are governed by actual environmental conditions as per IS: 9077 and IS: 9172. The main corrosion protection methods are given below:
- Controlling the Electrode Potential
- Inorganic/Metal Coatings or Organic/Paint systems
Taking care of the following points can provide satisfactory corrosion protection to most structural steel elements:
The design, fabrication and erection details of exposed structure should be such that good drainage of water is ensured. Standing pool of water, moisture accumulation and rundown of water for extended duration are to be avoided. The details of connections should ensure that
- All exposed surfaces are easily accessible for inspection and maintenance.
- All surfaces not so easily accessible are completely sealed against-ingress of moisture.
- Avoiding of entrapment and accumulation of moisture and dirt in components and connections by suitable detailing.
- Avoiding contact with other materials such as bimetallic connections.
- Detailing the structural steel work to enhance air movement and thereby keeping the surfaces dry.
- Providing suitable drain holes wherever possible to initiate easy draining of the entrapped water.
- Providing suitable access to all the components of steel structures for periodic maintenance, cleaning and carrying out inspection and maintenance at regular intervals.
- Providing coating applications to structural steel elements. Metallic coatings such as hot-dip galvanising, metal spray coatings, etc. are very effective forms of corrosion protection. Cleaning of the surfaces and applying suitable paints is the most commonly used and reliable method of corrosion protection.