Coastal areas
Coastal air contains a large amount of salt spray, which will strongly erode the surface of the steel screen, and it may also face harsh conditions such as strong winds and large temperature differences. Therefore, high-strength and high-corrosion-resistance weathering steel grades are the first choice:
Domestic grades: Q355NH and Q355NHE are preferred. Taking Q355NH as an example, it is a low-alloy high-strength weathering steel. It is added with copper, aluminum and other corrosion-resistant alloying elements. Its weather resistance is 2 - 8 times that of ordinary carbon steel. It can form a stable and dense rust layer on the surface in a corrosive environment to block further corrosion of the substrate. It is very suitable for manufacturing coastal architectural components such as screens. Q355NHE has better low-temperature impact toughness and can cope with the low-temperature and high-humidity environment in some coastal areas in winter, avoiding brittle fracture of the screen.
International grades: Corten B (corresponding to S355J2WP in European standards) is optional. It has excellent low-temperature impact performance while having corrosion resistance. It can resist the corrosion of salt spray and the impact damage caused by coastal storms to the screen, and is suitable for high-demand coastal landscape screens or public building exterior screens.
Inland areas
Most inland areas have low air salinity, and the corrosion factors are mainly ordinary wind, rain and dust. The corrosion rate of steel is much lower than that in coastal areas. Therefore, cost-effective basic weathering steel grades can be selected to balance performance and cost:
Domestic grades: Q235NH is a common choice. Its minimum yield strength is 235MPa, which can meet the structural strength requirements of decorative screens. It also has basic atmospheric corrosion resistance. In inland areas with little pollution, the rust layer formed on the surface can maintain long-term stability, and it is widely used in inland park landscape screens, residential community partition screens and other scenarios.
International grades: Corten A is applicable. It contains more phosphorus elements and has good atmospheric corrosion resistance. It is mostly used in architectural structures that do not require extremely high strength. It is suitable for inland decorative screens that focus on appearance and basic durability, and its cost is lower than that of Corten B, which can reduce the project budget.
