In-Plant Training Report Presentation
- 1. Roll No: 08085707 Registration No: 1834 Session: 2007-08 Department of Materials Science & Engineering Rajshahi University
- 2. BISCO PLANT We have visited the BISCO (BSRM Iron & Steel Co. Ltd.) plant, the mother-plant of BSRM where the production process of billets consist of mainly 3 section. Those are – • IF (Induction Furnace) section • LRF (Ladle refining furnace) Section • CCM (Continuous Casting Machine) Section They produce two types of billet Grade 40 (500CWR) • Grade 60 (420DWR) Name C Si Mn P S Grade 60 0.31-0.36 0.31-0.36 1.1-1.4 0.5 <0.5 Grade 40 0.18-0.24 0.18-0.24 0.75-0.90 0.5 <0.5
- 3. SCRAP • Old cars and machines or pieces of metal, etc. that are not now needed but have parts that can be used to make other things. • BSRM uses four types of scrap- 1.Sheredded 2.HMS 3.Bundle 4.DRI
- 4. One of the most common forms of wrought iron and steel scrap, heavy melting steel (HMS) is recyclable steel derived from a variety of sources—for example, railroad wheels, ship plates, construction scrap, auto and truck bodies. Shredded scrap steel is recyclable steel mainly extracted from obsolete automobile parts through the use of magnets, then “shredded”, i.e., cut into smaller, manageable pieces. Shredded HMS Shredded HMS
- 5. Direct-reduced iron (DRI), also called sponge iron, is produced from direct reduction of iron ore (in the form of lumps, pellets or fines) by a reducing gas produced from natural gas or coal. Bundle Sponge iron Bundle scrap is usually consists of long filament of recyclable scrap. It is collected from different types of tin container. Bundle/Fresh like DRI
- 6. Weight percentage of carbon in different scrap Sheredded = 0.5-0.6% HMS = 0.15-0.21% Bundle = 0.03-0.04% DRI = 0.1% Ferrous alloys are also poured into the furnace to create the quality. There are three types of ferrous alloys are used in the melt- Ferro Manganese (FeMn) Ferro Silicon (FeSi) Silicon Manganese (SiMn)
- 7. INDUCTION FURNACE PREPARATION The coil is first bound by silica tape. Mica block is inserted between two coils. Mica block and coil bound by glass tape again . For acidic lining they use ramming mass between the forma and coil. For binding the ramming mass with the coil they use grouting cement. Sintering the furnace at temperature 1417°C for 8 hour’s. Coil of Induction Furnace
- 8. Ramming mass 98.7% SiO2 + 1.3% H3BO3 250 kg Silica + 5 kg Boric Acid Sidewall = 5.6 tons Bottom = 1.5 tons Top Cap NaSiO3 = 1.2 tons Water = 200 Litres SiO2 = Balance Grouting Cement Al2O3 = 82-87% CaO = 5.8-6.8% Fe2O3 = 1-1.7%
- 9. INDUCTION FURNACE After sintering the furnace is looks as like the figure. The furnace is fully prepared for scrap melting. Induction furnace
- 10. FURNACE REPAIRING Three types repairing 1.Hot Patching 2.Patching 3.Full lining 1.Hot Patching • After 4/5 heats • Lining not broken • Bottom not broken 2.Patching • After 15/17 heats • Lining broken • Bottom broken 3.Full lining • After 15/16 patching ( 225 heats) • Coil repair
- 11. LADLE REFINING FURNACE Ladle Refining Furnaces are a proven technology used for producing alloy-steel, de- sulpharizing, de-oxidizing liquid steel and for improving the productivity from a steel plant. Ladle Refining is a post-melting treatment that is after melting in either the Induction Melting Furnace or Electric Arc Furnace Ladle Refining Furnace Argon Graphite Electrodes LRF
- 12. Ladle Preparation In ladle lining there are two zones • Metal zone (11 layer) • Slag zone (12 layer) Alumina brick is used in metal Zone. Carbon black brick is used in slag zone Ladle Metal ZoneAlumina Brick Carbon Black Brick
- 13. Operation procedure 1. Raise and keep molten steel temperature. The molten steel heated by arc to get new thermal energy. Graphite electrode use for arcing. 2. Lime (CaO) , CaF2 addition for slag making. 3. Pet coke, Met coke,CaC2, CaSi2-wire, FeMn, SiMn, FeSi etc are using for chemical adjustment. 4. Average process time (30-40 ) min. 5. Average arcing time (20-25) min. 6. Temp checking average (2-3) times. 7. Average 1st temp. at LRF (1585-1590) degree centigrade. 8. Average lifting temperature (1600-1605) degree centigrade. 9. Nitrogen/ Argon purging on whole process time for stirring of the molten metal promote homogenization.(After 20minutes using of Argon should be start in case of purging)
- 14. Slag Analysis Induction Furnace Slag LRF Slag SiO2: 60-80% MnO: 5-20% FeO: 10-15% Al2O3: 1-5% CaO: 56% SiO2: 13-15% FeO: 1.65% MgO: 6-7% Al2O3: 20%
- 15. CCM SECTION There are two steps involved in transferring liquid steel from the ladle to the molds. First, the steel must be transferred (or teemed) from the ladle to the tundish. Next, the steel is transferred from the tundish to the molds.
- 16. A severing unit (cutting torch or mechanical shears) to cut the solidified strand into pieces for removal and further processing.
- 17. Finally the billet is come into the billet section. Every billet is cutting down at a length of 12m and the cross sectional area is 160mm × 160mm.
- 19. NEW PRODUCT OF BSRM BSRM Xtreme BSRM Xtreme rebar’s are hot- rolled from prime quality steel billets and subjected to on-line thermo-mechanical treatment in three successive stages. 1.Quenching 2. Self Tempering 3. Atmospheric cooling
- 20. THANK YOU