Nitrogen as Substitute to Nickel While Preparing Stainless Steel in Mini Steel Plants Using Electric Arc/Induction Furnaces

Abstract

Nickel is a major alloying element in stainless steel which is added to stabilise the austenite but it is now being substituted by nitrogen in view of increasing cost of nickel. Nitrogen in the melt could be added as master alloy in electric arc and air induction furnaces. It can also be added in the melt by exposing it to nitrogen gas atmosphere. The total nitrogen absorbed in the melt willdepend upon mass transfer laws. In order to have gas/metal interaction, various melt conditions could be used in mini steel plants e.g., stirred melt exposure to gas in induction (vacuum type) furnace, gas bubbling through the melt in ladle or AOD converter and ionised gas exposure by plasma arc to the melt. The nitrogen addition method, using different melting techniques, is briefly descril'ed in this paper.