Lightweight steel and steel sheet with enhanced elastic modulus, and manufacturing method thereof

A lightweight steel with an enhanced elastic modulus, wherein:

• the lightweight steel has a chemical composition by mass percentage of 0.001%≤C≤0.30%, 0.05%≤Mn≤4.0%, 1.6%≤Al≤2.9%, 1.5%≤Ti≤7.0%, 0.5%≤B≤3.6%, at least one of the elements:
• 0.01%≤Si≤1.5%, 0.01%≤Cr≤2.0%, 0.01%≤Mo≤1.0%, 0.01%≤Nb≤0.2%, 0.01%≤V≤0.5%, 0.05%≤Ni≤1.0%, 0.05%≤Cu≤1.0%, and 0.001%≤Ca≤0.2%, and with a balance of Fe and unavoidable impurity elements;
• the lightweight steel has a microstructure comprising a matrix and fine hard reinforcing particles dispersedly distributed in the matrix uniformly, wherein the matrix is entirely or partially ferrite and/or bainite, wherein the hard reinforcing particles comprise at least TiB2;
• and
• wherein the lightweight steel has a tensile strength >500 MPa, an elastic modulus >200 GPa, and a density <7600 kg/m3.