Low-cost and high-strength steel for automobile crossbeam and manufacturing method thereof

The invention relates to a low-cost and high-strength steel for automobile crossbeam and a manufacturing method thereof. The automobile crossbeam comprises the following components by weight percent: C: 0.04-0.10%; Si: 0.2%-0.5%; Mn: 1.4-2.0%; P: less than 0.015%; S: less than 0.01%; Ti: 0.08-0.15%; Nb: 0.04-0.07%; N: less than 0.005%; O: less than 0.002% and the balance of Fe. The components for producing the automobile crossbeam are rolled by controlled rolling and cooling technology and can achieve the following comprehensive properties: ReL: 700-800MPa, delta >=18%.In addition, the components feature in excellent cold-bending and welding property, can meet manufacturing requirements of steel for the automobile crossbeam and enjoy excellent impact toughness.