“Strength and Plasticity of Metallic Materials” offers a detailed investigation into the strengthening and deformation behavior of metals, with a particular focus on the strain hardening of carbon steels. The book provide an in-depth analysis of how microstructural features—such as ferrite, cementite, martensite, and their combinations—affect the mechanical response under varying deformation and temperature conditions. Special attention is given to the influence of ferrite grain size, phase distribution, and low-temperature plastic deformation mechanisms on the overall strength and ductility of steels. By combining theoretical approaches with experimental insights, this work bridges the gap between materials science fundamentals and practical metallurgical applications, making it an essential reference for researchers, metallurgists, and graduate students studying the mechanical behavior of steels.