Abstract: A method for producing ultra-high strength martensitic cold-rolled steel sheet adopts pulsed ultra-rapid heating of cold-rolled martensitic steel sheets after smelting, solidification, hot rolling, billet or ingot casting, as well as conventional manufacturing processes such as hot continuous rolling and winding, pickling, and room temperature cold rolling. The steel sheets are rapidly heated at a heating rate of 100-500° C./s to a single-phase region of austenite, and then the samples are immediately water-cooled to obtain martensite structure without undergoing heat preservation or a very short holding time. The tensile strength of the martensitic steel is in the range of 1800-2300 MPa, and the total elongation can reach 12.3%. Compared with the continuous annealing product of the same martensitic steel, the tensile strength is increased by 700 MPa or more, and the maximum increase of total elongation is 6%.

Abstract: A method for manufacturing a lightweight steel plate with ultrahigh strength and high toughness includes, in percent by weight: 0.30-0.45 wt % C, 1.0-2.0 wt % Si, 2.0-4.0 wt % Al, 6.0-7.0 wt % Mn, 0.30-0.50 wt % V, 0.02-0.05 wt % Nb, 0.001-0.005 wt % B, N?0.003 wt %, P?0.015 wt %, S?0.005 wt %, Fe, and inevitable impurities.

Abstract: A method for manufacturing a lightweight steel plate with ultrahigh strength and high toughness includes, in percent by weight: 0.30-0.45 wt % C, 1.0-2.0 wt % Si, 2.0-4.0 wt % Al, 6.0-7.0 wt % Mn, 0.30-0.50 wt % V, 0.02-0.05 wt % Nb, 0.001-0.005 wt % B, N?0.003 wt %, P?0.015 wt %, S?0.005 wt %, Fe, and inevitable impurities.

Abstract: A method for producing ultra-high strength martensitic cold-rolled steel sheet adopts pulsed ultra-rapid heating of cold-rolled martensitic steel sheets after smelting, solidification, hot rolling, billet or ingot casting, as well as conventional manufacturing processes such as hot continuous rolling and winding, pickling, and room temperature cold rolling. The steel sheets are rapidly heated at a heating rate of 100-500° C./s to a single-phase region of austenite, and then the samples are immediately water-cooled to obtain martensite structure without undergoing heat preservation or a very short holding time. The tensile strength of the martensitic steel is in the range of 1800-2300 MPa, and the total elongation can reach 12.3%. Compared with the continuous annealing product of the same martensitic steel, the tensile strength is increased by 700 MPa or more, and the maximum increase of total elongation is 6%.