• Scrap Segregation: Our primary raw material is scraps. At BSI, only best quality foreign and local scraps are used to prepare deformed MS bars. At the very inception of melting, better quality scraps are segregated from mixed scrap zone and selected scraps are then collected for next operation.
• Charging: Selected scraps are charged to furnace for melting. BSI uses induction furnace as melting media.
• Chemical Analysis: After completion of melting, OES (optical emission spectroscopy) is conducted by a spectrometer to determine chemical composition of bulk material. Exact volume% of entire alloying elements is possible to determine by this process.
• Decarburization/ Re-carburization: Carbon is an important alloying element which plays an important role over properties of final product. The volume% of Carbon might be reduced, while excess amount of Carbon is found in bulk material, by using sponge iron, Vice versa, %Carbon can be increased by using CPC, cast iron etc.
• Alloy addition: We have to maintain optimal chemical composition to ensure presence of necessary properties. Several chemicals like FeSi, FeSiMn, and SiMn etc are incorporated with liquid metal to satisfy this requirement. Chemical analysis is again conducted just after chemical addition to the melt for checking whether required composition is attained or not. Otherwise entire system is repeated until desired composition is found.
• Temperature analysis: Temperature test is done, while melt is ready for pouring, by using pyrometer to check whether required temperature is attained or not. Melt is poured in a ladle after gaining necessary temperature.
• Degassing: Eradication of gases from bulk is a very important job since it creates internal porosities and piping which are very harmful for further uses. Aluminum is an excellent degassing agent and is added into ladle for removal of gasses.
• Pouring: Liquid metal is poured in to tundish of CCM following casting to prepare billets. Billets are the prime raw material for rolling mill.
Cutting: Billets made by CCM are cut into suitable pieces for rolling action.
Rolling: Entire rolling system can be divided into following parts:
• Reheating furnace: Billets are pushed into reheating furnace by means of pusher. In reheating furnace, billets are heated up to 1200°C to attain austenitic structure.
• Rolling: Heated billets are then rolled to prepare deformed MS bar. Strength of final product depends on grain size. Higher strength is found by reducing the grain size of product. So pass is a very important factor for rolling as higher number of passes of rolling system provides smaller size grain in products.
• Shearing: After rolling, finished products are cut into desired pieces and then sample is send to physical laboratory for quality assurance.
Physical Test: Here tensile test and microstructure study of final product is conducted and properties of our products are determined. Final certificate is given only if products attained required properties.
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