Annealing-free high-strength low-carbon boron-containing cold forging steel and preparation method thereof

The invention discloses annealing-free high-strength low-carbon boron-containing cold forging steel and a preparation method thereof. The cold forging steel is prepared from the following chemical components in percentage by weight: 0.12 to 0.16 weight percent of C, 0.06 to 0.10 weight percent of Si, 0.50 to 0.80 weight percent of Mn, less than or equal to 0.012 weight percent of P, less than or equal to 0.010 weight percent of S, 0.0020 to 0.0040 weight percent of B, 0.12 to 0.18 weight percent of Cr, 0.015 to 0.030 weight percent of Ti, 0.060 to 0.080 weight percent of Al and the balance of Fe and inevitable impurity elements. According to the annealing-free high-strength low-carbon boron-containing cold forging steel prepared through the method, the tensile strength is smaller than or equal to 500 MPa, the elongation is larger than or equal to 34.0%, the area reduction is larger than or equal to 70%, and excellent cold deformation capacity is achieved. When the annealing-free high-strength cold forging ste