The invention provides a method for improving the forming performance of ultra-low
carbon steel by regulating and controlling the Al / N value, and relates to the technical field of ultra-low
carbon steel. The method comprises the steps of
smelting,
forging, hot rolling, cold rolling and annealing. Wherein the
mass percent of each component of the cast
ingot is Clt; the steel comprises, by weight, 0.03% of Fe, less than or equal to 0.14% of Mn, 0.01-0.1% of Al, 0.0025-0.01% of N and the balance iron and residual elements, and the Al / N value ranges from 6.2 to 40. According to the method, the
nitride AlN can be rapidly generated by effectively utilizing the strong affinity of the
alloy element Al and the N element, the
solid solubility of free interstitial N atoms in steel is reduced, and the problem that the forming performance is weakened due to excessive N element is solved; after the Al / N value is increased, the size of a
nitride precipitated phase can be increased, the strength of a gamma texture ({111} / / ND) component is enhanced, and the strength of a Goss texture ({100} lt; 001gt, 001gt; the component strength eliminates the yield platform of the ultra-low
carbon steel, and improves the percentage elongation after fracture and the plastic strain ratio r value; the preparation method is simple and easy to operate, green and environment-friendly, low in cost, short in process, high in efficiency and beneficial to industrial large-scale production and popularization.