Acid Steel

Obsolete term for steel made in a furnace or converter lined with siliceous (acid) refractory material. In the open hearth and electric furnaces employing the acid process, the hearth or bottom consisted of fritted (“burned in”) silica sand. The acid Bessemer converter usually was lined with a kind of sandstone called “firestone.” Acid steel has been replaced by product from furnaces with basic linings, such as basic oxygen furnaces (BOF) and basic electric furnaces.