Microsturctural engineering by suitable thermo-mechanical treatment (TMT) (e.g. controlled rolling) and/or novel heat treatment can easily lead to high strength in low carbon steels. You can follow several methods pioneered by Prof Joydeep Maity (National Institute of Technology, Durgapur). Some of his recent works are
1) Article Attainment of an exceptionally high strength in low-carbon s...
2) Article Synthesis of Nano‐Particle Dispersed Highly Substructured St...
Also you might try to "produce the alloy" at a different way to improve qualities like ductility and UTS, using rapidly quenching techniques, that allow you to "freeze" the liquid composition. Some of them are roller quenching or powder made with nozzles . Then the powder or the flakes are extruded to end up wit a bar.