Question

Stainless steel does not rust because

(a) chromium and nickel combine with iron. 

(b) chromium forms an oxide layer and protects iron

(c) nickel present in it, does not rust. 

(d) iron forms a hard chemical compound with chromium present in it

Answer 1

(b) chromium forms an oxide layer and protects iron

Stainless steel or threaded steel bar is an alloy that contain metals, chromium & nickel. In Chromium, it should contain at least 10% of the steel alloy for stainless steel to be rust resistant. So, when the chromium is in contact with water, air, and acids, a thin layer of oxide forms to stop further corrosion.