What is an iron-based alloy containing 9-16% chromium called?

An iron-based alloy containing 9-16% chromium is referred to as stainless steel. This specific percentage of chromium provides exceptional resistance to corrosion and oxidation, which are hallmark properties of stainless steel. The addition of chromium creates a passive layer of chromium oxide on the surface of the steel, which protects it from rusting and gives it a distinctive shiny finish.

Stainless steel is used in a wide range of applications, from kitchen utensils and appliances to medical instruments and architectural structures, due to its durability and aesthetic appeal. The classification of stainless steel can vary further based on the alloying elements and specific compositions, but the key defining factor is the chromium content in this range that affords the corrosion-resistant properties.

The other materials mentioned do not fall under this specific range of chromium content or do not provide the same level of corrosion resistance as stainless steel.