WordNet records no synonym and no antonym for bessemer process. It is the only member of its synset, which is common for technical, taxonomic and single-sense vocabulary — there is no other English word that means the same thing. The broader and narrower terms below are the useful relations in that case.
Counts are distinct word forms across every sense. A synonym that appears under three senses is counted once here and shown three times below, under each sense it belongs to.
an industrial process for making steel using a Bessemer converter to blast air through molten iron and thus burning the excess carbon and impurities; the first successful method of making steel in quantity at low cost
Synonyms, antonyms and the broader and narrower relations for bessemer process come from Princeton University’s WordNet. Full sources and licences.