Hexavalent chromium is alloyed in steel for which property?

• A. Anticorrosive properties
• B. Aroma while welding
• C. Electrical conductivity
• D. Strength

Answer: (A)

Chromium in steel forms a thin, durable chromium oxide surface film that blocks water and oxygen from reaching the metal. This passive layer is self-healing if damaged, so the steel remains protected from rust and corrosion. That corrosion resistance is the defining benefit of adding chromium (including hexavalent chromium compounds used in coatings and plating), making anticorrosive properties the best explanation. The other options don’t fit: hexavalent chromium isn’t used to create an aroma during welding, it doesn’t primarily improve electrical conductivity, and while chromium can influence strength, corrosion resistance is the main reason it’s alloyed/used in this context.