Elinvar vs alloy steel

Elinvar and alloy steel both are nouns.

Word	Noun	Adjective	Verb	Adverb
Elinvar	Yes	No	No	No
alloy steel	Yes	No	No	No

As nouns, alloy steel is a hypernym of Elinvar; that is, alloy steel is a word with a broader meaning than Elinvar:

Elinvar: Elinvar is a trademark for a kind of steel used for watch springs because its elasticity is constant over a wide range of temperatures
alloy steel: steel who characteristics are determined by the addition of other elements in addition to carbon

Elinvar (noun)	alloy steel (noun)
Elinvar is a trademark for a kind of steel used for watch springs because its elasticity is constant over a wide range of temperatures	steel who characteristics are determined by the addition of other elements in addition to carbon