What is a key difference between cast steel and cast iron?

Cast steel typically exhibits greater strength and ductility compared to cast iron due to its lower carbon content, which usually remains below 1%. The presence of less carbon in cast steel allows for a more malleable structure, making it suitable for applications requiring higher strength and the ability to deform under stress without breaking, such as in construction and machinery components.

Cast iron, on the other hand, is characterized by a higher carbon content, which enhances its fluidity during casting but compromises its ductility and tensile strength. This difference in mechanical properties makes cast iron ideal for applications like engine blocks or pipe fittings, where brittle failure is less of a concern.

The other options touch on relevant aspects of materials science, but they do not capture the essential distinction in mechanical properties between cast steel and cast iron as effectively. The explanation around the differences in carbon content and resulting material properties is crucial for understanding why cast steel is often preferred in scenarios demanding higher strength and versatility.