GB/T 4171 Q355GNH weather steel plate, namely atmospheric corrosion resistant steel, is between the ordinary steel and stainless steel low alloy steel series.
GB/T 4171 Q355GNH weather steel plate is by general carbon steel with a small amount of copper and nickel and other corrosion resistant elements, with high quality steel welding, cutting, abrasion and high temperature fatigue characteristics.
GB/T 4171 Q355GNH weather steel plate chemical composition
| Grade |
C |
Si |
Mn |
P |
S |
Cu |
Cr |
Ni |
|
Q355GNH |
0.12 |
0.25-0.75 |
1 |
0.07-0.15 |
0.02 |
0.20-0.55 |
0.30-1.25 |
0.65 |
GB/T 4171 Q355GNH weather steel plate mechanical properties
| Grade |
Yield strength |
Tensile strength |
% Elongation in 2 in.(50mm) min |
|
Q355GNH |
355 |
490-630 |
22 |
Main Uses of Q355GNH High-Strength Weathering Steel
Architecture and Civil Engineering
A key material in modern construction and infrastructure, Q355GNH is widely utilized for external structural components and aesthetic design features. It is commonly applied in high-rise building facades, steel trusses for large-span structures (such as stadiums and convention halls), and pedestrian bridges, where its robust strength supports heavy structural loads, while its corrosion-resistant properties minimize long-term upkeep compared to traditional carbon steel. Additionally, Q355GNH is a preferred choice for public art projects, memorial statues, and landscaping elements, as it naturally develops a stable, rusted appearance (known as "patina") within 6–12 months, which retains an elegant, earthy look without peeling or degradation.
Transport Infrastructure
In transportation systems subjected to diverse corrosive elements, Q355GNH plays a vital role in ensuring longevity. For railway systems, it is used to manufacture rail-side signal masts, maintenance platforms, and bridge approach spans, effectively resisting corrosion caused by rain, dew, and periodic chemical runoff. In highway infrastructure, it serves as durable guardrails (especially in coastal or industrial zones), bridge expansion plates, and overhead gantries, resisting salt spray (caused by de-icing salts in colder climates) and moist conditions. In ports and waterways, it is used for wharf steel structures, cargo yard trestles, and ship docking hardware, effectively resisting the corrosive effects of saltwater mist and frequent exposure to moisture.
Industrial Equipment and Outdoor Installations
Q355GNH is integral to industrial applications requiring components to endure decades of outdoor use. In the energy sector, it is utilized for power transmission pylons, substation enclosures, and wind turbine tower bases, all of which must endure UV exposure, dust, and seasonal temperature shifts. In mining and bulk material transport, Q355GNH is used for constructing frame supports and chutes for outdoor conveyor systems (e.g., coal yards and ore docks), where its tensile strength resists impact from heavy materials and its resistance to corrosion combats exposure to dust-laden and humid atmospheres. It also serves as the protective casing for large outdoor storage silos (for materials like grain or construction supplies) and as fencing for chemical plant perimeters, withstanding industrial pollutants without premature rusting.
Mining and Construction Equipment
For heavy-duty machinery in outdoor, harsh environments, Q355GNH combines excellent strength and weather resistance, extending the equipment's useful life. It is used to manufacture key parts of open-pit mining equipment, including excavator bucket teeth, conveyor support structures, and crusher side plates, all of which must endure both abrasion from rough materials and corrosion from rain or runoff. In construction machinery, it is used in booms and outriggers of mobile cranes, as well as the frames of outdoor concrete pumps, where its tensile strength supports heavy-duty loads and its weathering ability prevents structural degradation due to rust during prolonged outdoor exposure.
