ET TMT Refined steel bars comprises Fe 550, Fe 500 D and Fe 550 D grades. These bars are made using the “integrated iron ore – induction furnace – ladle refining furnace” route which ensures the elimination of major impurities from steel. Use of iron ore as the raw material (as against scrap) ensures that the steel is tramp free. The refining in the LRF ensure low level of harmful impurities of sulphur and phosphorous. The “D” in Fe 500 D and Fe 550 D grades denote the enhanced ductility of the product. Fe 500 D has superior elongation properties and a high UTS/YS ratio. Lower quantities of carbon, sulphur and phosphorous, helps in preserving the steel and resisting earthquake shocks. Thus, making it the most appropriate choice for seismic zones, high-rise apartments, industrial structures, flyovers, windmills, highway construction, railway bridges, cantilever structures, airports, tunnels, ports, etc
On the other hand, Fe 550 D TMT bars come with superior tensile strength, better elongation properties, and a high UTS/YS ratio and thus is considered to be the perfect choice for large scale commercial projects and infrastructure projects in earthquake-prone areas.
At Electrotherm (India) Limited, advanced steel manufacturing facilities as well as the stringent quality controls at every step ensure production that complies with BIS specifications. After refining the steel in LRF, it is sent to a rolling mill and thermo mechanically treated in standard quenching box. Highly atomised quenching, selftempering and atmospheric cooling ensures that TMT bars have superior mechanical properties in strength, weldability, ductility and bendability meeting quality standards.
Sulphur and Phosphorus (S & P) are damaging impurities in steel. High levels of phosphorus can lead to ‘cold shortness’ in steel which makes it brittle under extreme cold conditions while high level of sulphur can lead to ‘hot shortness’ in steel, a condition in which the melting point of steel gets lowered thereby reducing its strength under high temperature. However, lower levels of S & P can be achieved only through advanced steel making technology.
Advantages of Refined Steel in manufacturing TMT bars:
ET TMT 500 D is ideal for:
Process of manufacturing refined steel:
Steel at Electrotherm is made using high quality raw material. The best quality iron ore is used in a Blast Furnace of 128 m3 and 63 m3, Direct Reduced Iron (DRI) kiln of 250 and 350 TPD. For this 100% iron ore is used. Steel scrap is not used in the melting process as it usually contains a high level of impurities. After melting the DRI from kilns and hot metal from Blast Furnace in Induction Furnaces, a unique and patented ERF-ELdFOSTM metallurgical process is used to dephosphorus the steel in the ladle and desulphurised the steel in Electrotherm Ladle Refining Furnace (LRF) specially to meet the stringent
phosphorus and sulphur requirement of all grades of TMT bars.
Multistage testing of steel chemistry on the spectrometer ensures adherence to the desired chemistry in close tolerance. In the LRF, metal is also homogenised, alloying elements are added and controlled in a very narrow range, dissolved gases in the steel are lowered through mild purging of inert gases and inclusions are removed or altered chemically to ensure high quality of steel.
This refined steel is cast into billets of required sizes in closed environment to have further control of gases and other inclusions. Molten pig iron (hot metal) from Blast Furnace and Direct Reduced Iron (DRI) from kiln is the key to making superior quality refined steel.
ET TMT bars are free from tramp elements like Cu, V, Ni, Cr etc. because they are manufactured from refined steel, unlike other conventional manufacturers where scrap is used and there is no control on impurities.
After refining the steel in LRF, it is rolled according to the required size in a state-of-theart Rolling Mill and thermomechanically treated in a Standard Quenching Box. Highly atomised quenching, self-tempering and atmospheric cooling ensures that refined steel TMT bars have superior mechanical properties in strength, weldability, ductility and bendability meeting or exceeding quality standards. Quality control is highly stringent
through NABL accredited labs and equipment.