The difference between Q355GNH and Q355NH weathering steel

Both Q355GNH and Q355NH weathering steel belong to low alloy series, with the characteristics of rust resistance, corrosion resistance, life extension, thinning and energy saving. The main difference between Q355GNH high weathering steel and Q355NH weathering steel is in chemical composition and mechanical properties.

Chemical composition of Q355GNH high weathering steel:
C: ≤0.12, S: 0.20-0.75, Mn: ≤1.00, P: 0.07-0.75, S: ≤0.020, Cu: 0.25-0.55, Cr: 0.30-1.25, Ni: ≤0.25

Chemical composition of Q355NH weathering steel:
C: ≤0.16, Si: ≤0.50, Mn: 0.50-1.50, P: ≤0.030, S: ≤0.030, Mo: ≤0.30, Cu: 0.25-0.55, Ti: ≤0.10, V: ≤0.12, Nb: ≤0.06, Cr: 0.40-0.80

Mechanical properties of Q355GNH high weathering steel:
Tensile strength: ≥ 490 - 630 MPa, Yield strength: ≤ 355 MPa, Elongation: ≤ 26

Mechanical properties of Q355NH weathering steel:
Tensile strength: ≥ 516 - 670 MPa, Yield point: ≥ 355 MPa

The performance and composition of Q355GNH high weathering steel are better than Q355NH weathering steel, and the former price is higher.

Weathering steel is often used to make structural parts such as railway vehicles, port buildings, containers, oil production platforms, chemical and petroleum equipment and containers containing hydrogen sulfide corrosive medium in oil derrick. Q355GNH and Q355NH weathering steel can also be used to manufacture tower, railway, bridge, vehicle and other steel structures exposed to the atmosphere for a long time.