Rust Removal Methods for Steel space structures

 The cross-sections of steel space frame components should be determined based on compressive strength and reliability calculations. To reduce the calculated length of compression members and improve reliability, measures such as adding sub-compression members and support frames can be adopted. 

The connection points of plate-shaped spherical space structures and two-shell spherical space structures made of stainless steel mainly include cross-plate connection points, welded hollow sphere connection points, and anchor bolt sphere connection points. Cross-plate connection points are suitable for steel space structures with channel steel components; the connection between the component and the connection plate is achieved by welding or high-strength bolts. Hollow sphere connection points and anchor bolt sphere connection points are suitable for steel space structures with seamless steel pipe components. The connection points of single-shell spherical space structures must also bear bending forces; under normal circumstances, the steel consumption of the connection points accounts for 15-20% of the total steel consumption of the steel space frame structure. The raw materials used in the construction of steel space structures are all relatively good corrosion-resistant building materials. However, over time, exposure to wind and rain will cause rust. Rust will affect the quality of the structure, and if not properly removed, it will cause even larger-scale corrosion. Therefore, we will introduce rust removal methods to help the spherical space frame structure extend its service life. 

1. Manual Rust Removal: Rust on stainless steel can be removed with a steel brush, stainless steel cloth, or coarse sandpaper until the original metal color is exposed, then cleaned with cotton yarn. This method is simple and economical, and can be used on small prefabricated components and prefabricated components with complex designs. Tools such as sandpaper, steel brushes, and scrapers can be used to remove rust.

2.Shot Blasting: This method uses compressed air pressure to continuously remove rust from the surface of the steel structure with quartz sand or steel shot, cleaning away oil stains and impurities, leaving only the original color.

3.Shot Blasting for Rust Prevention: This method utilizes a shot blaster's centrifugal impeller to draw in wear-resistant material, and the blade tips propel the material, removing impurities from the stainless steel surface through high-speed impact and friction. This method is less efficient than spraying, produces less air pollution, and is less expensive, but it has poor vibration control, and improper selection of wear-resistant material can easily cause deformation of the blasted part.

4. Spraying for Rust Prevention: This method uses compressed air that has undergone oil and water separation treatment to carry wear-resistant material, which is then sprayed at high speed onto the stainless steel surface through a nozzle. The impact and friction of the wear-resistant material remove iron oxide scale and other impurities, while also improving surface roughness. This method is highly efficient and provides good rust prevention, but it is more expensive. Spraying for rust prevention is divided into dry spraying and wet spraying methods. Wet spraying has better working conditions and produces less dust than dry spraying, but it is more prone to re-rusting. 

5. Pickling and passivation are necessary for rust removal. The steel frame must be immersed in an acid bath. If rust appears on the stainless steel, its service life will be reduced. Pickling and passivation are effective at removing rust, but remember to rinse with cold water afterward.

6. Power tool rust removal: This method uses compressed air or electromagnetic energy to create circular or reciprocating motions on a rust removal tool, generating friction or impact to remove rust or scale. This method is more efficient and produces higher quality results than manual rust removal and is currently a common rust removal method. Tools include pneumatic sanders, electric sanders, pneumatic steel brushes, and pneumatic chisels.