Krupp processKrupp process\ (Iron Metal.) (a) A process practiced by Friedrich Krupp, Essen, Germany, for washing pig iron, differing from the Bell process in using manganese as well as iron oxide, and performed in a Pernot furnace. Called also the Bell-Krupp process. (b) A process for the manufacture of steel armor plates, invented or practiced by Krupp, the details of which are secret. It is understood to involve the addition of chromium as well as nickel to the metal, and to include a treatment like that of the Harvey process with unknown variations or additions. The product is mentioned by some authors, as improved Harvey, or Harvey-Krupp armor plate.