High strength low alloy hot rolling ferrite bainite weathering resistant steel and production method thereof

The invention relates to a high strength low alloy hot rolling ferrite bainite weathering resistant steel and a production method thereof. The steel comprises the components by weight percent: 0.05-0.10% of C, 0.30-0.45% of Si, 1.00-1.50% of Mn, less than or equal to 0.015% of P, less than or equal to 0.01% of S, 0.50-0.70% of Cr, 0.20-0.30% of Ni, 0.20-0.40% of Cu, less than or equal to 0.05% ofAl, 0.01-0.025% of Ti, 0.03-0.05% of Nb and the rest of Fe and impurities; and the yield strength is more than or equal to 450MPa, and the welding cold crack susceptibility coefficient is less than orequal to 0.2. The invention has the advantages of low cost, high strength, low yield ratio, high weatherability, excellent weldability and low temperature toughness, simple process flow of the preparation technique and easy operation. Therefore, the invention can be widely applied to the fields such as bridges, buildings, containers, railway coaches, etc.