Ferrochromium is an iron alloy with chromium and iron as the main components, which is one of the main alloying agents used in the steel industry. Except for the main components of chromium and iron, it also contains impurities such as carbon, silicon, sulfur, and phosphorus. Ferrochromium contains 55% to 75% chromium, and is divided into high carbon (4% to 10%C), medium carbon (0.5% to 4%C), low carbon (>0.15% to 0.5%C) and micro-carbon (≤0.15%C) ferrochromium.
High-carbon ferrochromium is also called carbon ferrochromium, and medium, low and micro-carbon ferrochromium is also called refined ferrochromium. High-carbon ferrochromium produced from chrome ore with a low ferrochromium ratio, containing 50%-55% of Cr is called charge-grade ferrochromium, and nitrogen-containing ferrochromium containing 2%-10% of nitrogen is used as a nitrogen alloying agent, also known as ferro chromium ntride.
Ferrochromium is divided into high-carbon ferrochromium according to different carbon content, including charging grade ferro chromium (C≦10%), medium-carbon ferrochromium (C≦4.0%), low-carbon ferrochromium (C≦0.5%), and micro-carbon ferrochromium (C≦0.15%), etc. Also commonly used are silicon-chromium alloys and ferrochromium nitrides.
Ferrochromium is mainly used as an alloy additive for steelmaking, and it was added in the later stage of steelmaking in the past. To smelt low-carbon steels such as stainless steel, low-carbon and micro-carbon ferrochromium must be used, so the production of refined ferrochromium has been developed on a large scale. Due to the improvement of the steelmaking process, when the AOD method is used to produce stainless steel and other steel grades, carbon ferrochromium (mainly charging grade ferrochromium) is used to charge the furnace. Therefore, it is only necessary to adjust the composition of low-carbon ferrochromium in the later stage, so the current focus of ferrochromium production is to refine carbon ferrochromium.