Nickel-chromium low alloy steels are noted for which property?

• A. increase corrosion resistance
• B. improve machinability
• C. decrease hardenability
• D. increase hardenability and response to heat treatment

Answer: (D)

Nickel-chromium low alloy steels are valued for increasing hardenability and improving how the steel responds to heat treatment. Nickel and chromium help stabilize austenite and slow the transformation to softer phases during cooling, so more of the metal can harden when quenched. This lets you achieve higher hardness and strength after heat treatment, with good toughness, because the alloying elements control the transformation and promote a favorable microstructure after quenching and tempering. While chromium does contribute some corrosion resistance, and alloying can affect machinability, the defining note for these steels is their increased hardenability and better response to heat treatment. They don’t decrease hardenability; they enhance it, which is why that option best captures the property being described.