steel factory vs steel plant

steel factory and steel plant both are nouns.

Word	Noun	Adjective	Verb	Adverb
steel factory	Yes	No	No	No
steel plant	Yes	No	No	No

As nouns, steel factory and steel plant are synonyms defined as:

Other synonyms of steel factory include steel mill, steelworks.

steel factory (noun)	steel plant (noun)
a factory where steel is made	a factory where steel is made