A low density hot rolled steel including of 0.12%≤carbon≤0.25%, 3%≤manganese≤10%, 3.5%≤aluminum≤6.5%, 0%≤phosphorus≤0.1%, 0%≤sulfur≤0.03%, 0%≤nitrogen≤0.1%, 0%≤silicon≤2%, 0.01%≤niobium≤0.03%, 0.01%≤titanium≤0.2%, 0%≤molybdenum≤0.5%, 0%≤chromium≤0.6%, 0.01%≤copper≤2.0%, 0.01%≤nickel≤3.0%, 0%≤calcium≤0.005%, 0%≤boron≤0.01%, 0%≤Magnesium≤0.005%, 0%≤Zirconium≤0.005%, 0%≤Cerium≤0.1%, and the balance including iron and unavoidable impurities, the steel sheet having a microstructure including of ferrite from 60% to 80%, 10% to 35% kappa carbides (Fe,Mn)3AlCx, where x is lower than or equal to 1 and austenite from 0% to 10% wherein the microstructure grains having less than 4 GPa nano-hardness must be more than 45% and microstructure grains having nano-hardness of more than 5 GPa must be less than 10%.