What are the signs of rust in steel structures, and what hazards does it pose?

1. Rust in steel structures can be classified into three types:
① Mild rust: Pitting appears on the surface, and some components develop a layer of scale.
② Moderate rust: Distinct red rust spots and cracks in the scale.
③ Severe rust: The scale peels off, and the rust layer thickens. Thick rust layers can cause the surface of the steel structure to sag.

2. Major hazards caused by rust in steel structures:
① Rust reduces the load-bearing capacity of steel structures and affects their stability.
② Rust increases maintenance costs for steel structures.
③ Rust shortens the service life of steel structures.

If steel structures are not regularly maintained and treated promptly, rust stains and scale will accelerate corrosion and rust formation, not only shortening the service life of the structures but also creating potential safety hazards.

3. Effective Methods for Removing Rust from Steel Structures:

① Manual Rust Removal

Use tools such as manual scrapers, abrasive cloths, and wire brushes to remove rust from steel structures. However, this method is very inefficient and does not completely remove the rust.

② Mechanical Scraping

Use power tools to remove rust from steel structures. However, stubborn oxide scale cannot be removed, and the metal layer of the steel structure itself is easily damaged.

③ Chemical Rust Removal (Neutral Rust Remover)

Chemical rust removal primarily involves using a rust remover (neutral rust remover) to react chemically with the rust, causing the oxide scale to peel off the surface of the steel structure. When using a rust remover, it is best to choose a neutral rust remover, as this completely eliminates the drawbacks of acidic rust removers and acid mist damaging the base material.
Using neutral rust removers for steel structure rust removal offers advantages such as low cost, simple operation, and thorough rust removal. Neutral rust removers are not only suitable for rust removal on steel structures but also for steel components and on-site reinforcing bars.

Therefore, proper rust removal in steel structure construction is of great significance for the development of steel structure buildings and the reduction of environmental pollution. Furthermore, if long-term use is required without the need for major surface maintenance or long-term coating protection, the service life can reach approximately 20–30 years, resulting in lower maintenance costs and significant economic benefits.