1, composition: molten steel is mainly composed of iron and carbon with low carbon content. Hot metal refers to liquid iron obtained by melting iron ore without ironmaking or smelting treatment, and its main components are iron and high carbon content.

2. Usage: molten steel is mainly used to manufacture steel, including various structural steels, tool steels and stainless steels. Because the composition of molten steel can be adjusted to meet different needs, molten steel is widely used in industrial production. While hot metal is mainly used for casting in ironmaking and smelting, and for manufacturing iron castings, such as engine cylinder block and mechanical parts.