High-strength IF steel plate with yield strength of 170-300 Mpa level and production method

The invention provides a high-strength IF steel plate with yield strength of 170-300 Mpa level and a production method. The steel plate is prepared from, by mass, 0.004-0.010% of C, smaller than or equal to 0.030% of Si, 0.30-1.10% of Mn, smaller than or equal to 0.015% of P, smaller than or equal to 0.015% of S, 0.010-0.060% of Als, 0.010-0.080% of Ti, 0.010-0.060% of Nb, 0.010-0.050% of Cu, 0.0005-0.0080% of N, smaller than or equal to 0.0050% of O and the balance Fe and unavoidable impurity elements. Compared with the prior art, the high-strength IF steel plate has the advantages that the yield strength is greater than or equal to 170 MPa, the tensile strength is 330-460 MPa, the A80 is greater than or equal to 36%, the n value is greater than or equal to 0.19, the r value is greater than or equal to 1.6, and good matching of the strength and formation performance is achieved.