Atmospheric corrosion resistant Q500qDNH bridge steel plate

Q500qDNH bridge steel plate chemical composition (mass fraction)/%:
C ≤0.11, Si 0.15-0.5, Mn 1.1-1.5, Nb 0.01-0.1, V 0.01-0.1, Ti 0.006-0.03, Cr 0.45-0.7, Ni 0.3-0.4, Cu 0.25-0.55, Mo ≤0.2, N ≤0.008, Als 0.015-0.05
Note: 1. Al, V and Ti can participate alone or in combination. When participating in combination, at least one alloy element content shall reach the lower limit and Nb+V+TI ≤0.22%. 2. Ca treatment is required to control sulfide shape. 3. The lower limit of Mn content can reach 0.50% when the rolled plate is delivered. 4. When the total aluminum Alt content is used for calculation, the total aluminum content shall be 0.020%-0.055%.

Q500qDNH steel plate is delivered in thermo mechanical rolling state. The thickness of Q500qDNH steel plate is not more than 150mm, and the yield ratio is not more than 0.85. Q500qDNH steel plate is mainly used for erecting railway or highway bridges.

Mechanical properties of Q500qDNH bridge steel plate:
Tensile test: yield strength R/MPa under different thicknesses:
Thickness ≤ 50mm, ≥ 500
50mm ＜ thickness ≤ 100mm, ≥ 480
100mm ＜ thickness ≤ 150mm, -
Tensile strength R/MPa: ≥ 630
Elongation after fracture A/%: ≥ 18
Note: 1. When the yield is not obvious, Rp0.2 can be measured to replace the lower yield strength. 2. Take transverse sample for tensile test.

Q500qDNH bridge steel application:
The impact temperature of Q500qDNH steel plate is minus 20℃. It has good fatigue resistance, certain low temperature toughness and atmospheric corrosion resistance. It is a steel plate specially used for building railway or highway bridges.