Method for improving high plasticity of low-carbon silicomanganese cold-rolling transformation induced plasticity steels

The invention belongs to the technical field of rolled steel, and in particular relates to a method for improving high plasticity of low-carbon silicomanganese cold-rolling phase-change induced plasticity steel. The method comprises the following steps of: selecting the low-carbon silicomanganese cold-rolling transformation induced plasticity steels, smelting and forging so as to manufacture plate blanks, heating the plate blanks to be 1100-1250 DEG C, keeping the temperature, rough-rolling and finish-rolling the plate blanks and air-cooling the hot rolled plates to be 600-750 DEGC, coiling, and subsequently pickling so as to obtain steel plates for cold rolling; cold-rolling in a rolling reduction greater than or equal to 80%; heating the cold-rolled steel plates to be (Ac3-40 DEG C) to (Ac3+30 DEG C) at a heating velocity of at least 80 DEG C/s, carrying out annealing treatment for 5-15 seconds, subsequently cooling to a bainite area of 380-450 DEG C at a velocity of 40-80 DEG C/s, carrying out isothermal treatment for 10-50 seconds, and finally cooling to the room temperature. By utilizing the preparation method, cold-rolling transformation induced plasticity steels with high and strong plasticity is obtained, and the strength of the low-carbon silicomanganese cold-rolling transformation induced plasticity steels is greatly improved on the premise that the plasticity is not lost.