Which statement about chromium and steel is true?

• A. Chromium provides hardness and toughness to steel.
• B. Chromium has no effect on steel.
• C. Chromium makes steel lighter.
• D. Chromium reduces steel strength.

Answer: (A)

Chromium is added to steel to boost its hardness, wear resistance, and toughness, and in stainless steels it also provides corrosion resistance through a protective oxide layer. Proper heat treatment with chromium-containing steels can increase strength and hardness, while maintaining toughness, rather than reducing it. It does not make steel lighter—in fact, alloying usually adds some weight—and it certainly does not have no effect. So the true statement is that chromium provides hardness and toughness to steel.