Cold forging steel with excellent low-temperature toughness and manufacturing method thereof

The invention discloses cold forging steel with excellent low-temperature toughness, which contains Fe and inevitable impurities, and further contains the following chemical elements in percentage by mass: 0.17 to 0.23 percent of C, 0.17 to 0.37 percent of Si, 1.20 to 1.60 percent of Mn, 0.17 to 0.23 percent of Ni, 0.10 to 0.20 percent of V, 0.04 to 0.09 percent of Ti, 0.05 to 0.10 percent of Al and 0.005 to 0.009 percent of N. Correspondingly, the invention also discloses a manufacturing method of the cold forging steel, which comprises the following steps: (1) smelting; (2) LF refining; (3) VD or RH vacuum degassing; (4) continuous casting; (5) cogging, finishing and rolling into a wire rod; and (6) controlled cooling is conducted, specifically, it is ensured that the cooling speed of the wire rod is 1-5 DEG C/s, and the wire rod is cooled to 600 DEG C or below. 本发明公开了一种低温韧性优良的冷镦钢，其含有Fe和不可避免的杂质，其还含有质量百分含量如下的下述各化学元素：C：0.17～0.23wt.％、Si：0.17～0.37wt.％、Mn：1.20～1.60wt.％、Ni：0.17～0.23wt.％、V：0.10～0.20wt.％、Ti：0.04～0.