Benefits Of Stainless Steel Pickling In The Power Generation Industry

Stainless steel pickling is an important maintenance process for equipment and components used in the power generation sector, improving the reliability and durability of assets exposed to demanding conditions, and maintaining compliance with industry standards. The pickling process removes removes scale, weld heat tint and other metallic contaminants and restores the material properties of stainless steel components. This will then improve the material properties of stainless steel components.

Let’s look at this in more detail.

Chemical Reactions and Contaminant Removal

Stainless steel pickling involves exposing the component to a corrosive acid solution containing nitric and hydrofluoric acid. This "pickling solution" dissolves iron and chromium oxide scales and other unwanted surface deposits from the stainless steel. This effectively clears the surface of the component, allowing the thin protective passive layer – composed principally of chromium oxide – to reform, improving the application’s corrosion resistance and durability.

Prevention Against Damage and Corrosion

By means of pickling, stainless steel applications become better protected against various types of corrosion and damage, including crevice corrosion and pitting. ‘Pitting’ – caused by the localised breakdown of the passive layer – is a serious hazard in the chloride-rich environments common in powerplants. By ensuring the surface is in an optimal condition to form a complete passive layer, pickling mitigates the risk of pit and crevice initiation.

Benefits To Material Properties

Pickling is a crucial step in preparing metal components for service in power generation. By removing contaminants like rust and scale, pickling helps ensure the integrity and longevity of these components.

For turbine blades, pickling is essential to establish a clean surface for the formation of a protective passive layer. This layer is key to preventing corrosion and ensuring long-term performance.

Pickling can also benefit heat exchangers in power plant cooling systems. By removing surface contaminants, it helps ensure efficient heat transfer and prevents fouling, which can reduce efficiency and lifespan.

While not a substitute for regular maintenance, pickling provides a clean, uniform surface that contributes to the extended service life of power generation components and improves overall plant reliability.

Benefits Of Stainless Steel Chemical Cleaning

• Optimised Cleaning: Pickling creates a smooth, clean surface on stainless steel components, making subsequent cleaning and sanitisation processes more effective. This reduces the risk of microbial growth and contamination, further enhancing corrosion resistance and extending the lifespan of power generation equipment.

• Eliminates Contamination: Routine chemical cleaning, including pickling, prevents pitting and contamination in stainless steel equipment such as turbines, boilers, and cooling systems. This helps maintain efficient operation and reduces the risk of costly failures.

Compliance and standards

Stainless steel chemical cleaning also has compliance benefits, ensuring your application meets the standards and specifications set out in BS EN 2516 for the passivation of corrosion-resisting steels and nickel-based alloys, as well as the internationally recognised ASTM A380 and A967 standards.

Next steps

Get in touch with Inox Passivation today to find out about the pickling and passivation of stainless steel, and how we can support your operation.