History of stainless steel used in the offshore industry
In the 1930s, researchers at the British Steel Corporation and the German company, Krupp independently developed stainless steel by adding chromium to the steel alloy. The resulting material had a shiny surface, was highly resistant to corrosion and staining, and was much stronger and more durable than mild steel.
In the 50s & 60s, the discovery of large oil and gas reserves in the North Sea and Gulf of Mexico contributed to the growth of stainless steel. As exploration and production activities increased in both regions, Stainless steel was deemed an attractive solution due to its high corrosion resistance and strength to withstand the harsh marine environment.
What is the role of stainless steel in the offshore industry?
Unlike carbon steel, stainless steel adds a significant amount of chromium, protecting it from rusting when exposed to air and moisture. In addition, the chromium content helps prevent an iron oxide surface layer from forming thanks to a process known as passivation. Instead, a microscopically thin inert surface film of chromium oxide is generated when it comes into contact with oxygen in the air. This process occurs even in the water due to dissolved oxygen.
The chromium oxide layer prevents further corrosion because it blocks oxygen diffusion on the metal’s surface, protecting the core of the material. Furthermore, the outer layer can heal itself if it is scratched or disturbed by the environment, which allows it to withstand the harsh conditions of offshore environments, including high winds and waves. This makes it ideal for platform decks, handrails, and supports.
Types of stainless steel applications used in the offshore industry
1) Piping System
Stainless steel pipes and tubing are commonly used in oil and gas production and transportation to withstand harsh environments and corrosive fluids.
With its excellent corrosion resistance properties, stainless steel is ideal in offshore environments where the piping is exposed to seawater. Its resistance to corrosion helps to extend the life of piping systems and reduce maintenance costs.
Stainless steel is easy to clean and does not support bacterial growth, making it ideal for use in the offshore industry. In addition, it ensures that the water or fluids being transported through the piping and tubing systems remain clean and hygienic.
2) Storage Tanks
Offshore oil and gas platforms typically require large amounts of fuel. Storage tanks are used to store these fuels, including crude oil, natural gas, and diesel, to ensure a steady supply is always available.
Stainless steel storage tanks are used to store crude oil, refined petroleum products, and natural gas liquids (NGLs) due to their exceptional resistance to corrosion. In addition, the strength of stainless steel makes it ideal for large tanks with high strength requirements.
3) Offshore Platforms
Offshore structures are built specifically for drilling oil and gas deposits deep under the sea bed. Therefore, it will be exposed to powerful sea currents and the effects of saltwater corrosion.
Stainless steel is resistant to corrosion and offers a high strength-to-weight ratio for infrastructural applications, making it ideal for use in harsh marine environments.
PTS Metallographic team can inspect for you
When it comes to ensuring safety in the offshore industry, stainless steel is preferred due to its excellent corrosion resistance and durability. However, even the most robust materials can be subject to wear and tear over time, and it is crucial to detect any issues before they become more severe.
With extensive experience and expertise in metallographic analysis, PTS Metallography team can inspect your stainless steel components for any signs of corrosion, pitting, cracking, or other defects and ensure that your stainless steel components are up to the highest standards for your offshore industry.