Production method of nickel-free copper-phosphorus weathering steel casting blank

The invention provides a production method of a nickel-free copper-phosphorus weathering steel casting blank. The production method of the nickel-free copper-phosphorus weathering steel casting blank is characterized in that the nickel-free copper-phosphorus weathering steel casting blank comprises the following components of 0.05wt% to 0.10wt% of C, 0.30wt% to 0.50wt% of Si, 0.40wt% to 0.55wt% of Mn, 0.07wt% to 0.15wt% of P, less than or equal to 0.005wt% of S, 0.3wt% to 0.5wt% of Cr, 0.2wt% to 0.5wt% of Cu, 0.020wt% to 0.050wt% of Alt; less than or equal to 0.035wt% of Ti; no Ni alloy, and the balance Fe and inevitable trace elements, and the production method of the nickel-free copper-phosphorus weathering steel casting blank sequentially comprises the following process routes of molten iron desulfurization pretreatment, converter molten steel smelting, LF furnace molten steel refining and straight arc type slab casting machine continuous casting. According to the method, slag making material consumption a