Q890 high-strength steel produced by low-cost molybdenum-free controlled cooling process and manufacturing method of Q890 high-strength steel

The Q890 high-strength steel is prepared from the following raw materials in percentage by mass: 0.05 to 0.09 percent of C, 0.12 to 0.60 percent of Si, 1.55 to 1.85 percent of Mn, less than or equal to 0.020 percent of P, less than or equal to 0.010 percent of S, 0.015 to 0.060 percent of Nb, 0.010 to 0.060 percent of Alt, 0.0008 to 0.0025 percent of B, 0.008 to 0.020 percent of Ti, 0.20 to 0.60 percent of Cr, less than or equal to 0.15 percent of Ni, less than or equal to 0.15 percent of Cu, less than or equal to 0.0060 percent of N, less than or equal to 0.0030 percent of O, less than or equal to 0.0002 percent of H and the balance of Fe and inevitable impurities. According to the Q890 high-strength steel produced through the low-cost molybdenum-free controlled cooling process and the manufacturing method of the Q890 high-strength steel, by adjusting the proportion of C, Mn, Cr and B in the steel, the effects of the elements C, Mn, Cr and B are given full play to; mo is not added, and due to high price, the