How Laser Cleaning Improves Corrosion Resistance on Steel Surfaces

Discover how Laser Cleaning can improve the corrosion resistance on steel surfaces and why it is a better solution than traditional cleaning methods.

Laser cleaning can significantly improve the corrosion resistance of steel through a variety of mechanisms. Here’s a detailed explanation:

1. Removal of Contaminants and Oxides

Laser cleaning efficiently removes contaminants, oxides, rust, and other surface impurities from steel. By eliminating these substances, the laser exposes the pure metal surface. This clean surface is less likely to harbor points where corrosion can initiate.

2. Surface Passivation

The laser cleaning process can create a thin, uniform oxide layer on the steel surface. In a study published by AIP Advances, researches conducted a test to identify the micro-region morphology and element composition on carbon steel after being cleaned with a pulsed laser cleaning device. The results showed the relative content of Fe (Iron) on the surface of the sample after cleaning was increased, reaching over 90% from the 62% before cleaning.

Furthermore the relative content of Oxygen was reduced from 29% down to 2%–3%.

The researchers also carried out a comparison test with an angle grinder to study an abrasive cleaning method. The results with the angle grinder showed an increase in Iron content on the surface increased to only 68%, and Oxygen was reduced down to 27%.

The denser iron oxide formation provided by laser cleaning on the surface layer of steel, acts as a protective barrier, preventing further oxidation and reducing the rate of corrosion.

-TABLE 1: See the below table showing the comparison of present Iron and Oxygen elements within the sample steel sheets after being cleaned with an angle grinder and pulsed laser cleaners, of varying power. Reference- AIP Publishing

3. Surface Roughening

Certain Laser cleaning machines with the correct parameters can modify the surface roughness of steel. By creating a rougher surface at a microscopic level, the laser treatment enhances the adhesion of protective coatings or paints. These coatings adhere better to a laser-cleaned surface, providing a more effective barrier against corrosive environments.

4. Grain Refinement

Laser cleaning can induce localized heating and rapid cooling, leading to grain refinement in the steel surface layer. Finer grains in the steel improve its mechanical properties and increase its resistance to corrosion by reducing the pathways through which corrosive agents can penetrate.

5. Removal of Embedded Contaminants

Traditional cleaning methods may leave behind embedded contaminants within the steel surface. Laser cleaning with a Gaussian or CW laser, can effectively vaporise and remove these deep-seated impurities, ensuring a purer surface.

6. Environmentally Friendly Process

Laser cleaning is a non-contact, dry process that doesn’t require chemicals or abrasive materials. This reduces the risk of introducing new contaminants that could potentially cause corrosion.

 Through comparison and analysis, the use of laser cleaning technology can improve the surface cleanliness and corrosion resistance of metals, reduce maintenance times, and extend service life.

Practical Applications

In practical applications, laser cleaning is used in industries such as automotive, aerospace, and marine sectors, where enhanced corrosion resistance is critical. For example:

- Automotive Industry: Laser cleaning is used to prepare surfaces before welding or coating, ensuring stronger welds and better coating adhesion, leading to longer-lasting components.

- Aerospace Industry: Components exposed to harsh environments benefit from laser cleaning as it enhances the longevity and reliability of critical parts; furthermore laser cleaning can benefit during routine service checks and coating removal on precision components.

- Marine Industry: Steel structures and components in marine environments, which are prone to aggressive corrosion, are treated with laser cleaning to extend their service life.

Overall, by providing a cleaner, more uniform, and chemically stable surface, laser cleaning enhances the corrosion resistance of steel, thereby extending the material’s lifespan and performance in various applications.