Nickel-free weather-resistant steel and method for preparing hot rolled plate thereof

The invention provides nickel-free weather-resistant steel and a method for preparing a hot rolled plate thereof, and mainly solves the technical problems of high cold crack index, not very good welding performance and the like due to high C, Si and Mn content of the conventional nickel-free weather-resistant steel. The technical scheme is that: the weather-resistant steel comprises the following alloying ingredients in percentage by weight: 0.05 to 0.10 percent of C, 0.35 to 0.50 percent of Si, 0.38 and 0.50 percent of Mn, 0.07 to 0.11 percent of P, less than 0.010 percent of S, 0.45 to 0.60 percent of Cr, 0.25 to 0.45 percent of Cu, 0 to 50ppm of B, and the balance of Fe. The nickel-free weather-resistant steel of the invention is mainly used for replacing high-grade 09CuPCrNi weather-resistant steel.