Which one of the following metal is NOT an essential component in stainless steel ?
Iron
Nickel
Chromium
Tin
Answer is Wrong!
Answer is Right!
This question was previously asked in
UPSC NDA-2 – 2023
– The key element that provides its characteristic corrosion resistance (“stainless” property) is Chromium (Cr), which must be present in a minimum amount (typically 10.5% by mass). Chromium forms a passive, protective oxide layer on the surface.
– Nickel (Ni) is another common and essential alloying element in many widely used types of stainless steel, particularly austenitic stainless steels (like the 300 series, e.g., 304 and 316). Nickel enhances corrosion resistance, strength, and ductility.
– Tin (Sn) is not typically used as an alloying element in stainless steel. It is used in other alloys (like bronze, pewter, solder) or as a coating (tin plating), but it is not considered an essential component of stainless steel formulations.