Normalizing-type high-strength pressure vessel steel plate with good low-temperature toughness at minus 50DEG C and manufacturing method of normalizing-type high-strength pressure vessel steel plate

The invention discloses a normalizing-type high-strength pressure vessel steel plate with good low-temperature toughness at minus 50DEG C. The normalizing-type high-strength pressure vessel steel plate is made of chemical compositions comprising, by weight, 0.10-0.22% of C, not more than 0.40% of Si, 1.10-1.74% of Mn, not more than 0.015% of P, not more than 0.010% of S, not more than 0.40% of Ni, not more than 0.18% of V, 0.0070-0.0190% of N, 0-0.025% of Als, 0-0.018% of Ti, the balance of Fe and unavoidable impurities, wherein formulas: 3.5 /=460MPa, the tensile strength ranges from 630MPa to 740MPa, the ductility is >/=25%, the yield ratio is