The invention relates to on-line
quenching complex-phase structure hot-rolled wear-resistant steel. The on-line
quenching complex-phase structure hot-rolled wear-resistant steel comprises the following chemical components in percentage by weight: 0.14-0.18% of C, 1.5-2.0% of Mn, 0.20-0.35% of Cr, 1.0-1.3% of Si, 0.02-0.04% of Nb and the balance Fe and inevitable impurities. The preparation method comprises the working procedures of converter
smelting, slab
continuous casting, slab heating, controlled rolling, controlled cooling and coiling. In the slab heating process, a steel billet is heated to 1,200-1,280 DEG C, heat preservation is conducted for 3-4 h, the furnace discharging temperature is 1,150-1,200 DEG C, and the homogenization quality of the steel billet is guaranteed; and in the controlled cooling process, a sectional cooling process is adopted, namely, firstly, a hot-rolled plate is subjected to
water cooling to 600-700 DEG C for intercooling for 5-8 s, then, a steel plate is subjected to
water cooling to 100-200 DEG C, and finally, coiling is carried out. The Brinell
hardness of the produced hot-rolled wear-resistant steel is larger than or equal to 400 HBW, the tensile strength is larger than or equal to 1300 MPa, the yield strength is larger than or equal to 900 MPa, the
ductility is 10-15%, the cold bending performance meets the condition that D is equal to 3a, 120-degree qualification is achieved, and the
impact energy at the temperature of-40 DEG C is larger than or equal to 65 J; a
microstructure is an
austenite + ferrite +
martensite three-phase structure, and the ferrite content is 12%-18%; and the technological process is simple and the production cost is low.