What is the chemical composition of Q345NQR2 steel?

Q345NQR2 under TB/T 1979-2014 standard is a new atmospheric corrosion resisting steel grade.
Q345NQR2 steel equivalent:
09CuPTiRE-A hot rolled plate
Q345NQR2 steel chemical composition (%)
C max: 0.12, Si:0.25-0.75, Mn:0.20-0.50, P: 0.06-0.12, S max:0.020, Cu: 0.25-0.50, Cr: 0.30-1.25, Ni, 0.12-0.65

Q345NQR2 atmospheric corrosion resisting steel is added by a small amount of alloying elements Cu, P, Cr, Ni, etc. to form a protective layer on the metal surface to improve atmospheric corrosion resistance. Weather-resistant structural steel is divided into two types: high weather-resistant steel and welded weather-resistant steel. High weathering structural steel has better resistance to atmospheric corrosion, while welded weathering steel has better welding performance. Q345NQR2 weather-resistant structural steel is 2 to 8 times more resistant to atmospheric corrosion than ordinary steel.