Q550 D high-quality structural iron medium and heavy plate and production method thereof

The invention discloses a Q550 D high-quality structural iron medium and heavy plate, produced by smelting and rolling C, Si, Mn, Nb, V, Ti, Mo, B, Als and Fe. According to the invention, by properly adjusting the content and proportion of C, Mn, Nb, V, Ti, and Mo in the Q550D(E), strictly controlling the content of P and S, and cooperating the production technology disclosed herein, the characteristics of low carbon equivalent, high strength, high toughness, good weldability and the like of the structural iron medium and heavy plate can be guaranteed, the production technology can be simplified, the production flow can be shortened, and the production energy consumption can be reduced. The Q550 D high-quality structural iron medium and heavy plate is suitable for large-scale production operation.