HiB steel produced at moderate slab heating temperature and production method thereof

The invention relates to HiB steel produced at a moderate slab heating temperature, which comprises the following components in percentage by weight: 0.055-0.095% of C, 2.95-3.35% of Si, 0.040-0.070% of Mn, no more than 0.02% of P, 0.010-0.025% of S, 0.004-0.010% of N, 0.05-0.15% of Sn, 0.005-0.04% of Cr, 0.01-0.1% of Cu, 0.020-0.032% of Als, 0.0020-0.010% of Mo, 0.001-0.05% of Se and 0.001-0.02% of Sb. The production method comprises the following production steps: heating a casting slab to 1280-1350 DEG C; performing hot rolling; coiling; performing one-stage or two-stage normalization; rolling through a single cold rolling method or a double cold rolling method containing intermediate annealing; performing decarburizing annealing in a wet N2+H2 atmosphere; performing one-stage or two-stage nitriding annealing; coating separant; performing high-temperature annealing; performing stretching and leveling annealing; and coating an insulating layer. According to the invention, the HiB steel is produced at a moderate slab heating temperature, so that the problems of difficult matching of congenital and postnatal inhibitors, instable property and the like after the slab heating temperature is reduced at present can be solved; and the congenital inhibitor and postnatal inhibitor are controlled in a unified manner, thus ensuring the final magnetic property stability of the product.