What is GB/T 4171 Q345GNH Steel?

GB/T 4171 Q345GNH is a Chinese (GB/T standard) low-alloy weather-resistant (corten) structural steel, meaning it forms a protective, stable rust layer when exposed to weather, giving it enhanced atmospheric corrosion resistance, typically with a minimum yield strength of 345 MPa (megapascals), and is used for outdoor structures like bridges, containers, and sculptures, balancing cost with durability. 

Grade (Q345GNH):

• • Q: Stands for “Q” (Yield Strength).
  • 345: Indicates a minimum yield strength of 345 MPa.
  • GNH: Denotes a Weathering Structural Steel (G = Structural, N = Weathering, H = High Strength/Application).