High-yield-strength S890QL structural steel medium plate and production method thereof

The invention discloses a performance-satisfying and flaw-detection-satisfying high-yield-strength S890QL structural steel plate of which the thickness is less than 100 mm (included). The structural steel plate comprises the following chemical components in percentage by mass: 0.10-0.14wt% of C, 0.25-0.45wt% of Si, 1.35-1.65wt% of Mn, no more than 0.008wt% of P, no more than 0.003wt% of S, no more than 3.5wt% of microalloying elements (V+Nb+Ti+Cr+Ni+B+Cu), no more than 0.045wt% of Als and the balance of Fe and residual elements, wherein 0.3satisfying and flaw-detection-satisfying high-yield-strength S890QL structural steel plate of which the thickness is less than 100 mm (included). The yield strength is controlled at 860-950 MPa, and the tensile strength is controlled at 930-1050 MPa; the extension percentage is controlled at 12-20%; and the V type-20 DEG C longitudinal impact work is controlled at 180-300 J. The S890QL has the characteristics of high strength, good toughness, fine low-temperature toughness, good processability and weldability and the like.