Sulfuric acid dew point corrosion resistant steel plate with high weather resistance and manufacturing method thereof

The invention relates to a sulfuric acid dew point corrosion resistant steel plate with high weather resistance. The steel plate comprises the following chemical components in percentage by weight: 0.06%-0.12% of C, 0.20%-0.45% of Si, 0.8%-1.2% of Mn, 0.07%-0.13% of P, less than or equal to 0.0080% of S, 0.020%-0.050% of Nb, 0.020%-0.050% of V, 0.020%-0.050% of Al, 0.30%-0.60% of Cr, 0.10%-0.40% of Ni, 0.30%-0.50% of Cu, 0.0005%-0.020% of Ca and the balance of Fe and inevitable impurity elements. The atmospheric corrosion resistance index I is greater than or equal to 7.0, and the manufacturing process flow of the steel plate is KR pretreatment-gt; a converter-gt; lF refining-gt; performing RH vacuum degassing-gt; ca treatment-gt; continuous casting-gt; and rolling. The matrix structure of the obtained steel plate is a uniform and fine ferrite and pearlite mixed structure. The grain size is 6-30 [mu] m. The head, middle and tail properties of the steel plate are uniform and stable, the yield strength ranges f