Cold-rolled hot-formed steel and manufacturing method thereof

The invention discloses cold-rolled hot-formed steel and a manufacturing method thereof. The cold-rolled hot-formed steel comprises the following chemical components in percentage by mass: 0.25 to 0.35 percent of C, 1.2 to 1.5 percent of Mn, 0.3 to 0.6 percent of Si, 0.04 to 0.06 percent of Al, 0.2 to 0.35 percent of Cr, less than or equal to 0.03 percent of P, less than or equal to 0.03 percent of S, 0.01 to 0.03 percent of Nb, 0.02 to 0.04 percent of Ti, 0.02 to 0.10 percent of Cu, 0.0015 to 0.003 percent of B and the balance of Fe and inevitable impurities. The manufacturing method comprises the steps of smelting, continuous casting, hot rolling, pickling and cold rolling, continuous annealing, leveling and hot forming. The hot-formed steel provided by the invention has good mechanical properties, effective control of a hot-formed oxide layer in an unprotected atmosphere is also realized, and the thickness of the oxide layer is less than or equal to 2.5 microns. 本发明公开一种冷轧热成形钢及其制造方法，冷轧热成形钢的化学成分及质量百分比为：C：0.2