Ferrochrome is classified according to its carbon content into high-carbon ferrochrome, including charging grade ferrochrome (C≦10%), medium-carbon ferrochrome (C≦4.0%), low-carbon ferrochrome (C≦0.5%), and micro-carbon ferrochrome (C≦0.15%). Other commonly used types include silicon-chromium alloys and ferrochrome nitride. Ferrochrome is primarily used as an alloying additive in steelmaking, historically added in the later stages of refining. However, the smelting of low-carbon steels such as stainless steel necessitates the use of low- or micro-carbon ferrochrome, leading to a significant expansion of refined ferrochrome production.
Due to improvements in steelmaking processes, such as the AOD method (see ladle refining), carbon ferrochrome (mainly charging grade ferrochrome) is used in the furnace for the production of stainless steel. Therefore, only the addition of low- or micro-carbon ferrochrome in the later stages is needed to adjust the composition. Consequently, the focus of ferrochrome production has shifted to the refining of carbon ferrochrome.
