Q460D steel plate meeting standard of forgings produced by continuous casting billets and manufacturing method thereof

The invention relates to a Q460D steel plate meeting the flaw detection standard of forgings produced by continuous casting billets and a manufacturing method thereof. The steel plate takes Fe as a basic element and comprises the following chemical components in percentage by mass: 0.11 to 0.15 percent of C, 0.20 to 0.40 percent of Si, 1.30 to 1.50 percent of Mn, less than or equal to 0.010 percent of P, less than or equal to 0.003 percent of S, 0.60 to 0.80 percent of Ni, 0.20 to 0.40 percent of Cr, 0.03 to 0.05 percent of Nb, 0.04 to 0.07 percent of V, less than or equal to 0.20 percent of Mo, less than or equal to 0.20 percent of Cu, 0.002 percent of B and inevitable impurity elements; and the carbon equivalent is greater than or equal to 0.45. According to the Q460D steel plate meeting standard of the forgings produced by the continuous casting billets and the manufacturing method thereof provided by the invention, a continuous casting billet with the thickness of 450 mm is adopted for production, the pro