Excellent Atmospheric Corrosion Resistance: The Q235NH steel plate incorporates alloy elements such as phosphorus (P), copper (Cu), chromium (Cr), and nickel (Ni), enabling the formation of a dense oxide protective film on its surface. Its resistance to atmospheric corrosion is significantly superior to that of ordinary Q235 steel, making it particularly suitable for harsh environments such as humid and industrial atmospheres. Its weathering resistance is 2-8 times that of ordinary carbon steel, with a corrosion rate controlled at ≤0.03mm/year in industrial environments.
Stable Mechanical Properties: The steel plate exhibits a yield strength of ≥235MPa and a tensile strength ranging from 470-630MPa, with an elongation after fracture of ≥21-26%. It combines good plasticity, toughness, and cold working performance. In low-temperature environments, its impact energy is ≥27J at -20°C and remains stable at -40°C. It passes the 180° cold bending test (d=2a), making it suitable for various structural processing applications.
Natural Rust Layer Protection on Surface: When used in the atmosphere for extended periods, a uniform "rust-red" oxide layer forms on the surface, preventing further corrosion penetration. This eliminates the need for frequent painting and maintenance, reducing long-term costs. Once the rust layer stabilizes, it provides permanent protection, with an outdoor lifespan exceeding 50 years.
Good Weldability and Machinability: The steel plate supports various delivery conditions, including hot rolling, controlled rolling (TMCP), and normalizing. For welding, J507CuCr low-hydrogen electrodes (SMAW) are preferred, with a heat input controlled at ≤30kJ/cm and an interpass temperature of ≤150°C. The cut surface requires coating with epoxy zinc-rich primer for rust prevention. Additionally, it supports laser, plasma, flame, and waterjet cutting, facilitating easy machining and forming.
Combination of Economy and Practicality: The cost of Q235NH steel plate is lower than that of stainless steel and high-alloy weathering steel, while its comprehensive performance meets general weathering structural requirements. The paint-free design saves 150 yuan/m² in costs and reduces maintenance costs by 70% over 30 years. Compared to traditional steel, it achieves an 8% weight reduction (with a lightweight coefficient of 0.92), making it suitable for large-scale applications such as bridges, vehicles, containers, and building steel structures.
