| abstract |
A 980 MPa-grade hot-rolled dual-phase steel and a manufacturing method therefor. The chemical components of the steel comprise, in percentage by weight, 0.10%-0.20% of C, 0.8%-2.0% of Si, 1.0%-2.0% of Mn, 0-0.02% of P, 0-0.005% of S, 0-0.003% of O, 0.02%-0.06% of Al, 0-0.006% of N, 0.01%-0.06% of Nb, 0.01%-0.05% of Ti, and the balance of Fe and inevitable impurities. In addition, the components need to meet the following relation: 0.05%≤Nb+Ti≤0.10. The microstructure of the steel is made of ferrite and martensite. The average grain size of the ferrite is 5-10 μm, and the equivalent grain size of the martensite is 15-20 μm. The yield strength of the steel is greater than or equal to 500 MPa, the tensile strength of the steel is greater than or equal to 980 MPa, and the ductility A80 is greater than or equal to 12%; the steel has excellent strength, ductility and tenacity matching and a relatively low yield ratio, and can be applied to parts requiring good formability, high strength and reduced thickness, such as wheels. |