The present invention provides a weather resistant steel plate, which comprises components of, by
mass percent, 0.02 to 0.10 of C, 0.10 to 0.40 of Si, 1.0 to 1.6 of Mn, less than or equal to 0.025 of P, less than or equal to 0.015 of S, 0.20 to 0.50 of Cu, 0.30 to 0.60 of Cr, 0.10 to 0.50 of Ni, less than or equal to 0.40 of Mo, less than or equal to 0.060 of Nb, less than or equal to 0.060 of V,0.010 to 0.035 of Ti, less than or equal to 0.0030 of B, less than or equal to 0.0050 of Ca, 0.015 to 0.050 of Al, and the balance Fe and other unavoidable impurities. Correspondingly, the present invention also provides a manufacturing method of the weather resistant steel plate. Through reasonable distribution ratio of
alloy components, the method provided in the invention can obtain a high-strength and high-
toughness weather resistant steel plate with good
corrosion resisting performance, high yield strength and tensile strength, and excellent low temperature
impact toughness. The steel plate also possesses good
weldability, being able to carry out
welding without preheating or employ lower preheating temperature
welding. The steel plate provided in the invention can be widely applied to large-scale steel structure
engineering such as building structures, bridges, etc.