Slag Engineering Methodology for Enhanced De-Sulphurisation Capability in Si Deoxidised Steels

Somnath Kumar¹ , K K Keshari² , A K Bandhyopadhyay³ , Abdhesh Prasad⁴ , Vikash Kumar⁵ , N. Sen⁶ , K Choudhury⁷ , R Kumar⁸

Section:Research Paper, Product Type: Journal-Paper
Vol.7 , Issue.4 , pp.14-21, Dec-2020

Online published on Dec 31, 2020

Copyright © Somnath Kumar, K K Keshari, A K Bandhyopadhyay, Abdhesh Prasad, Vikash Kumar, N. Sen, K Choudhury, R Kumar . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 

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Abstract :
The quality requirement of customers is becoming more stringent w.r.t low level of sulphur in final product for a better mechanical property of steel. High sulphur in steel leads to poor internal quality in the form of cracks and sometimes causes breakout during continuous casting of steel. In past, different works have been conducted by many researchers to investigate desulphurisation process in steelmaking. Very few studies are available on desulphurisation of steels deoxidised with Si-Mn having a lower basicity top slag. High sulphur in steel was one of the bottlenecks in improving the quality of steel as well as a reason for lower throughput of continuous casters at Durgapur Steel Plant (DSP). De-Sulphurisation of silicon killed steel is a difficult task owing to the inherent nature of steel melt as well as ladle top slag. The present work was carried out in improving the desulphurisation level in steels subjected to silicon killing. Slag engineering was done in a novel way to make conditions more conducive for desulphurisation of steels. Deoxidation and flux addition practice was modified in an innovative way to decrease the SiO2 generation and also to reduce the oxygen potential of slag. Plant scale trials were conducted with modified deoxidation and flux addition practice. 60% De-S was achieved in heats i.e sulphur reduction from 0.039% (S in hot metal) to 0.015% (S in the final product). Process technology was established for the production of low sulphur steels at Durgapur Steel Plant.

Key-Words / Index Term :
Steel Desulphurisation, Slag Engineering, Sulphide Capacity, Deoxidation, Inclusions, Clean Steel

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