The Steel Industry ... Galvanized into Action on the Durability Question

Corrugated Steel Pipe

Corrugated steel pipe (CSP) has been a staple in various infrastructure projects due to its strength and flexibility. However, its durability has historically been a point of concern, particularly with galvanized steel, which has shown suboptimal performance in certain environments.

Limitations of Galvanized Steel

Galvanized steel pipes, while providing initial protection against corrosion, often fell short in aggressive environments. This led to a search for more reliable solutions, which brought about advancements in coating technologies.

Advancements in Aluminized Type 2 (ALT2) Coating

Aluminized Type 2 (ALT2) coating has emerged as a superior alternative to traditional galvanization. The modern ALT2 is vastly improved compared to its earlier versions from the 1970s through the early 2000s, thanks to several key advancements:

1. Enhanced Quality Control

  • The steel industry has significantly improved quality control standards, ensuring consistent coating weight, application, and adherence.

2. Modernized Aluminizing Process

  • The aluminizing process has been refined to ensure better uniformity and adhesion of the aluminum-silicon alloy coating to the steel substrate. This results in fewer defects and more consistent performance.

3. Improved Coating Formula

  • Technological enhancements of online equipment and upstream processing lead to a more uniform and consistent coating and alloy layer, offering better corrosion resistance and an extended lifespan. These improvements are continually updated based on feedback and scientific studies.

4. Surface Quality Control

  •  Advances in surface quality control and surface conditioning practices have led to smoother coatings, improving hydraulic performance and reducing runoff stickiness.

5. Better Protective Properties

  • The commercially pure aluminum coating of ALT2 offers superior resistance to oxidation and other forms of corrosion compared to traditional galvanized coatings and ALT1 coatings.

6. Improved Mechanical Forming Properties

  • The inherent nature of ALT2 results in increased fatigue resistance, making it more durable under various loading and forming conditions.

Installation and Performance

The installation of ALT2 systems has become widespread, with thousands of systems being installed in North America annually. While the exceptional performance of these systems often goes unmentioned, any issues are quickly noted, emphasizing the importance of continued advancements and quality control.

Specialized Formulas for Different Markets

The ALT2 formula is tailored specifically for the CSP market based on extensive studies. Variations of the formula are used for other markets, such as automotive, construction, and industrial applications, to ensure optimal performance in each specific environment.

In conclusion, the evolution of Aluminized Type 2 coating has significantly enhanced the durability and longevity of corrugated steel pipes, making them a reliable choice for modern infrastructure needs.