High-strength steels, such as weathering steel, typically have a significantly heavier galvanized coating than carbon steel. Generally, the thickness of the galvanized layer is greatly affected by the surface roughness of the steel before galvanizing. However, in the case of weathering steel, the coating weight is comparable for pickled and sandblasted surfaces, whereas in carbon steel, sandblasted surfaces are typically galvanized with a heavier coating. Therefore, the increased thickness of the galvanized coating on weathering steel is primarily due to the absence of higher silicon content found in typical carbon steel. It is well known that high silicon content (e.g., the silicon content in ASTM A588 Grade A) promotes the growth of the iron-zinc alloy layer during hot-dip galvanizing (Grade A has approximately 0.40 Si, while carbon steel typically has less than 0.02 Si), which ultimately increases the overall coating thickness.
The appearance of the galvanized coating on weathering steel also differs slightly from the typical coating on carbon steel. Bright galvanized steel is characterized by a relatively pure zinc coating near the surface; conversely, matte galvanized steel is characterized by a coating composed of an iron-zinc alloy.
When galvanizing weathering steel, a matte gray coating with few or no glitter should be expected. Bright galvanized steel is characterized by a relatively pure zinc coating near the surface; conversely, matte galvanized steel is characterized by a coating composed of an iron-zinc alloy. When galvanizing weathering steel, a matte gray coating with few or no glitter should be expected. Bright galvanized steel is characterized by a relatively pure zinc coating near the surface; conversely, matte galvanized steel is characterized by a coating composed of an iron-zinc alloy. When galvanizing weathering steel, a matte gray coating with few or no glitter should be expected.
Company profile
Founded in 2008, Gnee (Tianjin) Supply Chain Group Co., Ltd. specializes in the global trade and processing of Corten steel products.
• We handle all kinds of Corten engineering projects, such as bridges, gardens, hotels, and facade systems.
• Compliant with ASTM, EN, and other international standards; third-party inspection supported.
• Exported to over 200 countries and regions worldwide.
• 8 subsidiaries across China and overseas, ensuring global service coverage.
Application Fields: Architecture, landscaping, gardening, cladding, and urban infrastructure.
