Low-cost non-quenched and tempered high-strength wear-resistant steal plate with yield strength of 780 MPa grade and manufacturing method thereof

The invention discloses a low-cost non-quenched and tempered high-strength wear-resistant steal plate with a yield strength of 780 MPa grade, which comprises the following chemical components in percentage by weight: 0.08 to 0.13 percent of C, less than or equal to 0.5 percent of Si, 1.6 to 1.9 percent of Mn, less than or equal to 0.015 percent of P, less than or equal to 0.01 percent of S, 0.6 to 1.0 percent of Cr, 0.1 to 0.15 percent of Ti, 0.02 to 0.06 percent of Nb, less than or equal to 0.005 percent of N, less than or equal to 0.002 percent of O, and the balance of iron (Fe) and inevitable impurities. A manufacturing method of wear-resistant steel comprises the steps of electric furnace or converter smelting, refining, continuous casting, continuous casting bloom heating, hot continuous rolling, laminar flow cooling, coiling, decoiling and cutting to obtain a finished plate. A high-strength steel strip of the invention can achieve the following combination properties that: the ReL is 780 to 840 MPa, the Rm is 850 to 930 MPa, delta is more than or equal to 16 percent, the high-strength steel strip meets high wear resistance, and compared with Q345B, the wear resistance is improved by more than 2 times.