This alloy is used to increase tensile strength and yield strength of steels. With that, chromium increases hardness and wear resistance of carbon steels and confers stainless properties to low-carbon steels (with chromium content in them 12 % min).
Ferrochromium is subdivided into 4 groups according to the carbon content:
- high-carbon grades with the carbon content from 4.0 to 9.0 %;
- medium-carbon grades with the carbon content from 0.5 to 4.0 %;
- low-carbon grades with the carbon content 0.5 % max;
- low-carbon nitrogen-bearing grades with the nitrogen content 1.0–6.0 %.
Ferrochromium is delivered in lumps not more than 315 mm in size and 20 kg in mass or according to size classes. It is acceptable to produce high-carbon ferrochromium in pigs weighing up to 30 kg.
Ferrochromium is supplied in bulk. However, ferrochromium of any grade and size class may be packed by agreement with the customer. Several batches of ferrochromium transported in bulk by the same vehicle should be separated by partitions to avoid the possibility of their mixing.
As in the case of ferrosilicon, the surface of ferrochromium should be free of slag, sand and other foreign materials. Only oxide films and foundry facing are allowed. Foreign materials should also be absent on the fracture surface in ferrochromium lumps.