High-carbon ferrochromium

Ferrochromium is the most important raw material for the production of stainless steel, mainly used in the production of stainless steel, ball bearing steel, tool steel, nitrided steel, heat-strength steel, quenched and tempered steel, carburized steel and hydrogen-resistant steel. There is only one element that determines the properties of stainless steel, which is chromium, and each stainless steel must contain a certain amount of chromium.  

Smelting process

The smelting methods of high carbon ferrochromium include blast furnace method, electric furnace method, plasma furnace method, etc. Using a blast furnace can only produce special pig iron with a chromium content of about 30%. As of 2012, most of the high-carbon ferrochromium with high chromium content is smelted in the submerged arc furnace by the flux method.

The basic principle of electric furnace smelting of high carbon ferrochromium is to reduce the oxides of chromium and iron in chromium ore with carbon. The starting temperature of carbon reduction of chromium oxide to generate Cr2C2 is 1373K, the starting temperature of the reaction to generate Cr7C3 is 1403K, and the starting temperature of the reaction to reduce chromium to 1523K, so when carbon reduces chromium ore, what is obtained is chromium carbide, not metallic chromium . The level of carbon content in ferrochromium depends on the reaction temperature. It is easier to form carbides with high carbon content than carbides with low carbon content.

Application

High-carbon ferrochromium is mainly used in the production of stainless steel, of which 200 series stainless steel contains about 16% chromium, 300 series stainless steel contains about 25% chromium, and 400 series stainless steel contains about 14% chromium. The 300 series stainless steel, which is in the largest demand for ferrochromium, is also the largest proportion of stainless steel production.

Used as an alloying agent for ball steel, tool steel and high-speed steel with high carbon content to improve the hardenability of steel, increase the wear resistance and hardness of steel; as an additive for cast iron, improve the wear resistance and hardness of cast iron At the same time, the cast iron has good heat resistance; it is used as a chromium-containing raw material for the production of silicon-chromium alloys and medium, low and micro-carbon ferrochromium by the slag-free method; it is used as a chromium-containing raw material for the production of metal chromium by electrolysis; used for oxygen blowing Raw material for smelting stainless steel.