IF steel with delta r less than or equal to 0.3 and production method thereof

The invention relates to IF steel for an automobile with delta r less than or equal to 0.3 and a production method thereof. The IF steel comprises the following chemical components in percentage by weight: 0.0009 to less than or equal to 0.0049 percent of C, less than or equal to 0.015 percent of Si, 0.07 to 0.21 percent of Mn, less than or equal to 0.025 percent of P, 0.015 to 0.049 percent of Nb, 0.01 to 0.06 percent of Ti, 0.015 to 0.07 percent of Als, less than 0.015 percent of S, less than 0.005 percent of N, and the balance of Fe and inevitable impurities. The production method comprises the following steps of: smelting and continuous casting to form a blank; heating the continuous casting blank; rough rolling; finish rolling; reeling; cold rolling, continuous annealing; cooling; polishing for later use. The IF steel can replace the traditional ultra-low carbon Ti-IF steel, and has good deep drawing property, low delta r value and excellent welding property. The obtained automobile parts have excellent quality and attractive appearance, and defects such as lug or avulsion and the like are reduced.