Nb-containing micro-alloyed high-carbon steel hot-rolled wire rod and manufacturing method thereof

The invention comprises an Nb-containing micro-alloyed high-carbon steel hot-rolled wire rod and a manufacturing method thereof. The invention belongs to the technical field of hot-rolled wire rods. The hot-rolled wire rod comprises the components of, by mass: 0.83-1.00% of C, 0.15-0.35% of Si, 0.6-0.9% of Mn, 0-0.50% of Cr, 0-0.15% of V, 0.01-0.20% of Nb, and balance of Fe. A converter is adopted; a double slag method is adopted; and high tensile carbon operation is adopted. Slag is blocked, and molten steel is tapped. Recarburization is carried out by using a low-nitrogen recarburizer. When steel is fetched from an LF refining station, an oxygen activity is controlled below 10ppm. In a refining final slag, a total amount of FeO and MnO is no higher than 3%. An inclusion modification treatment is carried out on a Ca-Si line. 160mm*160mm small billets are adopted. Terminal electromagnetic stirring is adopted in cooperation of a crystallizer. Full-protection and constant-pulling-speed casting is carried out by using a continuous casting machine. A reasonable secondary cooling system is adopted. An appropriate open rolling temperature is controlled, such that shrinkage cavity welding probability is increased. Pre-water-cooling and phase-transformation-strengthening cooling technology are applied for controlling tissue and performance. After aging, mechanical property tensile strength of the wire rod is higher than 1280MPa, and an area reduction is greater than 30%.