Stainless steel is used in most applications where high levels of sanitation and cleanliness are paramount. As such, tubular steel is highly used in the manufacture of food service equipment, hospital equipment, and in kitchen and bathroom fixtures. It is also used widely in manufacturing, engineering, and construction industries. However, corroded stainless steel cannot perform to the required expectations regarding high standards of hygiene and cleanliness. Corroded steel tubes have high chances of developing structural problems and failure. When you need steel fabricated, it is important to understand corrosion, its causes, and prevention measures even before the metal is fabricated.
Causes of corrosion
Steel is preferred for its high level of corrosion resistance; however, this does not mean that it cannot corrode. Environmental factors such as moisture, acidity level, and pollutants such as sulfates in the environment can be blamed for speeding up the rate of corrosion of steel. If the tubular steel product is exposed to the atmosphere or bare soil, corrosion can be accelerated by these factors.
Different types of steel have varying levels of corrosion resistance. Types of steel that are more anodic on the galvanic chart such as low alloy steels and mild steels have a higher susceptibility to corrosion. Cathodic steels such as stainless steel are more resistant to corrosion.
Types of corrosion
There are different types of corrosion experienced on tubular steel products. They depend on the environment to which the steel product is exposed to, and they include the following:
- Galvanic corrosion. It occurs when steel comes into contact with a dissimilar metal in the presence of an electrolyte solution. For example, if steel comes into contact with zinc or aluminium in the presence of water, the rate of corrosion of steel will be accelerated.
- Crevice corrosion: it occurs when steel products are placed in very tight spaces where there is no free flow of oxygen. With time, corrosion compounds begin to build up on the surface and eat at the metal.
- Weld corrosion: If the carbon content of steel is high and a lot of heat is used during steel fabrication, it triggers a chemical reaction which contributes to corrosion.
How to prevent tubular steel corrosion
Prevention measures should be observed right from the steel fabrication stage. Some steps that can be taken during this stage include the following:
- Choosing the right metal alloys such as molybdenum and chromium which make steel highly resistant to corrosion.
- Ensuring full passivation of tubular steel during fabrication by using an acid bath to activate the process synthetically.
- Using non-metal connectors when using dissimilar metals to prevent galvanic reactions.
- Powder coating tubular steel to avoid exposure to corrosive elements.
Choosing a qualified steel fabricator is one of the best ways to ensure that you choose the right steel alloys for your application and that your tubular steel products will be able to resist corrosion.Share