Ferroalloys
Ferroalloys are used for deoxidation and alloying of steel, high content grades are also used for reduction of metals from oxides.Ferrosilicon is a ferroalloy main components of which are iron and silicon. It is used for dioxidation and alloying of steel.
Ferrochromium is an alloy of iron and chromium, used for alloying of steel and alloys.
Ferromanganese is used for steel deoxidation.
Ferromanganese
Ferromanganese is an alloy of iron and manganese.
Variety of steel grades causes the necessity of production of manganese and manganese alloys of wide assortment.
The most widely spread ferromanganese alloys are: high carbon and low carbon ferromanganese with various allowable limits of carbon, phosphorous and other impurities;
- silicomanganese with wide range of silicon content, phosphorus, carbon and other impurities;
- metal manganese produced by electrolytic and thermal-electric methods of production
- nitrated metal manganese and silicomanganese.
Ferromanganese is produced from the manganese ores containing mainly pyrolusite MnO2 with 63% Mn content. The coke is 3-15 mm, with content of ash less than 12%, moisture less than 11%, phosphorus less than 0.02% is used as a reducer.
GOST 4755 - 91 (ISO 5446 - 80)
1. Chemical composition.| Grade (GOST) | Fraction of total mass, % | ||||
| Mn | C | Si | P | S | |
| max | |||||
| Low carbon ferromanganese | |||||
| FeMn90(À) | 85,0 - 95,0 | 0,5 | 1,8 | 0,05 | 0,02 |
| FeMn90(B) | 85,0 - 95,0 | 0,5 | 1,8 | 0,30 | 0,02 |
| Medium carbon ferromanganese | |||||
| FeMn88(À) | 85,0 - 95,0 | 2,0 | 3,0 | 0,10 | 0,02 |
| FeMn88(B) | 85,0 - 95,0 | 2,0 | 3,0 | 0,40 | 0,02 |
| High carbon ferromanganese | |||||
| FeMn78(À) | 75,0 - 82,0 | 7,0 | 6,0 | 0,05 | 0,02 |
| FeMn78(B) | 75,0 - 82,0 | 7,0 | 6,0 | 0,70 | 0,02 |
| FeMn70(À) | 65,0 - 75,0 | 7,0 | 6,0 | 0,30 | 0,02 |
| FeMn70(B) | 65,0 - 75,0 | 7,0 | 6,0 | 0,70 | 0,02 |
1. Upon customer’s request ferromanganese is produced with fraction of total mass of manganese for grade FeMn70 not les than 70%, for grade FeMn78 – not less than 78%.
2. Definition of ferromanganese grade contains alloy basis, fraction of total mass of carbon, silicon and phosphorus.
High carbon ferromanganese| Grade (ISO) | Fraction of total mass, % | ||||
| Mn | C | Si | P | S | |
| íå áîëåå | |||||
| FeMn75C80VHP | 70,0 - 82,0 | 8,0 | 2,0 | 0,50 | 0,03 |
| FeMn75C80HP | 70,0 - 82,0 | 8,0 | 2,0 | 0,35 | 0,03 |
| FeMn75C80MP | 70,0 - 82,0 | 8,0 | 2,0 | 0,25 0 | ,03 |
| FeMn75C80LP | 70,0 - 82,0 | 8,0 | 2,0 | 0,15 | 0,03 |
| FeMn75C80VLP | 70,0 - 82,0 | 8,0 | 2,0 | 0,10 | 0,03 |
| Grade (ISO) | Fraction of total mass, % | ||||
| Mn | C | Si | P | S | |
| max | |||||
| FeMn80C20 | 75,0 - 85,0 | 1,5 - 2,0 | 2,0 | 0,35 | 0,03 |
| FeMn80C20LP | 75,0 - 85,0 | 1,5 - 2,0 | 2,0 | 0,20 | 0,03 |
| FeMn80C15 | 75,0 - 85,0 | 1,0 - 1,5 | 2,0 | 0,35 | 0,03 |
| FeMn80C15LP | 75,0 - 85,0 | 1,0 - 1,5 | 2,0 | 0,20 | 0,03 |
| FeMn80C10 | 75,0 - 85,0 | 0,5 - 1,0 | 2,0 | 0,35 | 0,03 |
| FeMn80C10LP | 75,0 - 85,0 | 0,5 - 1,0 | 2,0 | 0,20 | 0,03 |
| FeMn90C20 | 85,0 - 95,0 | 1,5 - 2,0 | 2,0 | 0,35 | 0,03 |
| FeMn90C20LP | 85,0 - 95,0 | 1,5 - 2,0 | 2,0 | 0,20 | 0,03 |
| FeMn90C15 | 85,0 - 95,0 | 1,0 - 1,5 | 2,0 | 0,35 | 0,03 |
| FeMn90C15LP | 85,0 - 95,0 | 1,0 - 1,5 | 2,0 | 0,20 | 0,03 |
| FeMn90C10 | 85,0 - 95,0 | 0,5 - 1,0 | 2,0 | 0,35 | 0,03 |
| FeMn90C10LP | 85,0 - 95,0 | 0,5 - 1,0 | 2,0 | 0,20 | 0,03 |
| Grade (ISO) | Fraction of total mass, % | ||||
| Mn | C | Si | P | S | |
| max | |||||
| FeMn80C05 | 75,0 - 85,0 | 0,1 - 0,5 | 2,0 | 0,30 | 0,03 |
| FeMn80C05LP | 75,0 - 85,0 | 0,1 - 0,5 | 2,0 | 0,15 | 0,03 |
| FeMn80C01 | 75,0 - 85,0 | äî 0,1 | 2,0 | 0,30 | 0,03 |
| FeMn80C01LP | 75,0 - 85,0 | äî 0,1 | 2,0 | 0,15 | 0,03 |
| FeMn90C05 | 85,0 - 95,0 | 0,1 - 0,5 | 2,0 | 0,30 | 0,03 |
| FeMn90C05LP | 85,0 - 95,0 | 0,1 - 0,5 | 2,0 | 0,15 | 0,03 |
| FeMn90C01 | 85,0 - 95,0 | äî 0,1 | 2,0 | 0,30 | 0,03 |
| FeMn90C01LP | 85,0 - 95,0 | äî 0,1 | 2,0 | 0,15 | 0,03 |
| Grade (ISO) | Fraction of total mass, % | |||||
| Mn, not less than | C | Si | P | S | N | |
| max | ||||||
| Sintered | ||||||
| FeMn80C05N2 | 80,0 | 0,1 - 0,5 | 2,0 | 0,15 | 0,03 | 1,5 - 2,5 |
| Baked | ||||||
| FeMn70C05N5 | 69,0 | 0,1 - 0,5 | 2,0 | 0,30/0,15 | 0,03 | 4,0 - 8,0 |
| FeMn70C10N5 | 69,0 | 0,5 - 2,0 | 2,0 | 0,35/0,20 | 0,03 | |
Ferromanganese is supplied in pieces 20 kg max or in form of crushed particles. Crushed ferromanganese is supplied according to size grades listed in the following table:
Main requirements| Size grade | Piece dimensions, mm | Fraction of product’s total mass, % | Max dimensions of oversize product, mm | |
| oversize | undersize | |||
| 1 | 20 - 200 | 10 | 10 | 315 |
| 2 | 20 - 100 | 10 | 10 | 200 |
| 3 | 5 - 100 | 10 | 10 | 200 |
| 4 | 5 - 50 | 10 | 10 | 100 |
| 5 | 5 - 25 | 10 | 15 | 50 |
| Size grade | Range of pieces dimensions, mm | Max. product’s fraction of total mass, % | ||
| oversize | undersize | |||
| total | less than 3,15 mm | |||
| 1 | 100 - 315 | 10 Any piece should not exceed more than1.15 times the maximum limit of the given size range in two or three directions. | 15 | 7 |
| 2 | 25 - 200 | 15 | 7 | |
| 3 | 10 - 100 | 15 | 7 | |
| 4 | 3,15 - 50 | 7 | ||
| 5 | 3,15 - 25 | 7 | ||
| 6 | äî 3,15 | - | ||
If the ferromanganese is produced in pieces the quantity of fines passing through the sieve with mesh 20õ20 ìì should not exceed: 15% of lot mass – for low and medium carbon ferromanganese, 10% of lot mass – for high carbon ferromanganese FeMn78; 20% of lot mass – for high carbon ferromanganese FeMn70.
Piece of 20kg and more are allowed in quantity less than 5% of lot mass.
Surface of the pieces should not contain any foreign materials. Traces of antiburning-on materials (lime, sand), dross, slag impurities and graphite traces are allowed.