Which property is lower in cast iron compared to structural steel?

Which property is lower in cast iron compared to structural steel?

• A. Density
• B. Tensile strength
• C. Electrical conductivity
• D. Hardness

Answer: (B)

Tensile strength is the property that tends to be lower in cast iron than in structural steel. Cast iron has a high carbon content and a brittle microstructure (often with graphite flakes or other hard phases) that interrupts the continuous path for deformation. Under pulling loads, this brittleness causes cracks to initiate and grow quickly, so it can’t sustain as much tensile stress before fracturing. Structural steel is designed with a softer, more ductile microstructure (ferrite/pearlite or tempered phases) and lower carbon content, which allows more plastic deformation before reaching its maximum tensile stress, giving it higher tensile strength. Density and hardness can vary with specific grades, but for tensile loading, cast iron typically underperforms compared with structural steel.

Tensile strength is the property that tends to be lower in cast iron than in structural steel. Cast iron has a high carbon content and a brittle microstructure (often with graphite flakes or other hard phases) that interrupts the continuous path for deformation. Under pulling loads, this brittleness causes cracks to initiate and grow quickly, so it can’t sustain as much tensile stress before fracturing. Structural steel is designed with a softer, more ductile microstructure (ferrite/pearlite or tempered phases) and lower carbon content, which allows more plastic deformation before reaching its maximum tensile stress, giving it higher tensile strength. Density and hardness can vary with specific grades, but for tensile loading, cast iron typically underperforms compared with structural steel.