Question

Steel is mainly an alloy of iron and:
A.Chromium
B.Nickel
C.Manganese
D.Carbon

Answer 1

Hint:Steel is mainly an alloy of iron and a non-metal which gives a greenhouse gas on combustion. As other elements like chromium, nickel etc. are present in less amount.

Complete step by step answer:
- An alloy is a combination of metals with metal/other elements. For example Red gold is an alloy made by combining gold and copper, similarly an alloy like sterling silver is made by combining silver and copper. The resulting mixture has properties that often differ from those of combining metal in their pure state.
- An alloy is generally ductile, electrical conductor, lustrous like metal. Alloys are used in making infrastructure, aerospace industry, non sparking tools and etc. Making alloy is a cost effective method for using the metal while preserving important properties. Examples of alloys are steel, solder, brass, pewter, bronze, amalgam, duralumin.
- Steel is an alloy of iron (metal) and carbon. Adding carbon to iron to make steel alloy, provide strength and fracture resistance properties. The carbon in typical steel alloys may contribute up to $$2.14\mathrm{\%}$$ of its weight. A steel alloy with less carbon may be weak, ductile and soft. Alloy steel also has intentionally added other elements like manganese, nickel, chromium, cobalt, tungsten, titanium, boron, vanadium, molybdenum. But their contribution in steel is less than that of carbon but still adds strength to the alloy.

Thus, the correct option is D.

Note:
An alloy of iron with more than $$2.14\mathrm{\%}$$ of carbon contribution is known as cast iron. Cast iron has lower melting point than typical steel alloy and also has good castability.