Metals generally possess high strength and good plasticity. Their unique texture, luster, and natural beauty have always attracted the attention of signage designers. Stainless steel and other metal materials have always been indispensable signage and advertising materials.
In recent years, a special metal material that has gained popularity in related industries such as landscape architecture has also received high praise in the signage industry-Corten steel.
Material brief introduction
Corten steel, also known as atmospheric corrosion resistant steel, originated from Corton steel in North America and is a low-alloy steel series between ordinary steel and stainless steel. It is made by adding small amounts of corrosion-resistant elements such as copper and nickel to ordinary carbon steel, possessing the strength, toughness, ductility, formability, weldability, abrasion resistance, and high-temperature resistance of high-quality steel. Its weather resistance is 2 to 8 times that of ordinary carbon steel, and its paintability is 1.5 to 10 times that of ordinary carbon steel. Simultaneously, it has rust resistance, enabling components to have corrosion resistance, extended service life, reduced thickness and consumption, and labor and energy savings.
Material properties
- 1. Unique Expressive Characteristics: It possesses outstanding visual expressiveness; Corten steel changes over time. Its color, brightness, and saturation are higher than ordinary structural materials, giving medium to large-sized signs made of weathering steel a unique flavor, a distinctive sense of power, and making them eye-catching. It is particularly commonly used in parks, gardens, and industrial parks.
- 2. Strong Form-Making Capability: Corten steel is relatively easy to mold into a variety of shapes while maintaining excellent integrity.
As a new generation of advanced steel material, Corten steel has outstanding visual expressiveness, and its corrosion resistance becomes more pronounced with longer use. The rough surface produced by the corrosion of the steel plate gives the work a greater sense of volume and quality. Its special feature is that, exposed to the natural environment over time, a corrosion-resistant protective layer forms on the surface, eliminating the need for painting protection, and the material's lifespan exceeds 80 years.
Weathering plate rusting process
The rusting process for Corten steel plates generally employs a rust stabilization treatment.
This involves using chemical methods (rust-injecting liquid) to slowly dissolve the surface film of the steel plate, stabilizing it and forming a uniform rust layer. This rust layer provides protection and inhibits the rust that initially appears in the steel during its initial use.
Note: The time required for a stable, dense, rust-red protective layer to form from brand-new Corten steel plates is considerable, sometimes taking up to six years in dry regions. Therefore, rust accelerators are commonly used in the market to accelerate rust formation. Care must be taken to select a suitable rust accelerator and appropriate processing methods.
Common product types are categorized into four main types: profiles, plates, pipes, and wires.
- Profiles: Profiles refer to straight steel bars with a defined cross-sectional shape and a relatively large length-to-circumference ratio.
- Plates: When the dimensions of profiles cannot meet requirements, or when manufacturing large structural components, plates from weathering steel materials are used. Perforated weathering steel plates are a uniquely shaped plate with a distinctive texture and visual effect.
- Pipes: Pipes are hollow tubular steel materials, commonly used in load-bearing structures.
- Wires: Wires are products less than 8mm thick obtained from cold-drawn round steel, also known as high-strength wire. They can be woven into mesh and used for small signs, landscape features, and decorative purposes.
Parameters of Corten Steel
Corten steel sheets typically range in thickness from 1.5mm to 4mm, medium sheets from 4mm to 20mm, thick sheets from 20mm to 60mm, and extra-thick sheets can reach 80mm. Widths are standard at 0.5m, 1m, 1.2m, 1.5m, 2m, etc.
matters need attention
- 1. Pay attention to the natural conditions of the site. Indoor and outdoor environments, inland and coastal areas, and different locations all affect the rust growth rate and composition of Corten steel, including air salt content, humidity, sunlight, building shape, and orientation. Therefore, uneven rusting will inevitably occur.
- 2. Corten steel is not non-corrosive, but it corrodes more slowly. High-quality Corten steel has a lifespan eight times that of ordinary steel (annual corrosion rate of 0.097mm on one side). A small thickness allowance for corrosion should be considered during manufacturing, and water accumulation should be avoided. Pay close attention to the drainage design near the bottom of the weathering steel.
- 3. Sample colors of Corten steel are not very reliable. The color gradually transitions from bright yellow, earth yellow, orange-yellow, orange-red, reddish-brown, to brown. Therefore, when using Corten steel to make signs, the design should use the last color and the initial color changes should be clearly communicated to the client.
key points of construction
- 1. Corrosion at weld points: The oxidation rate at weld points must be the same as that of other materials, requiring special welding materials and techniques.
- 2. Water corrosion: Corten steel is not stainless steel. If water accumulates in the recesses of Corten steel, the corrosion rate will accelerate. Therefore, proper drainage is essential.
- 3. Salt-rich air environment: Corten steel is sensitive to salt-rich air environments like those in Hawaii. In such environments, the surface protective film may not be able to prevent further internal oxidation.
- 4. Discoloration: The rust layer on the surface of Corten steel can cause nearby objects to become rusty.
- 5. Temperature: It is best to carry out fabrication and installation in environments below 35 degrees Celsius and above 5 degrees Celsius, as this will affect the surface rusting effect.
