India’s Steel Ministry Committee Rejects Proposal: Ship-breaking Steel Plates Not Fit for TMT Bars
In a recent development, a committee established by India’s Steel Ministry has rejected the proposal to utilize ship-breaking steel plates for the production of TMT bars, also known as rebars. The decision was based on the committee’s evaluation of non-standardized offerings and the lack of comprehensive data. The rejection stems from the committee’s inability to establish a Standard Operating Procedure (SoP) for the usage of ship plates without thorough testing of their chemical composition.
Committee Composition:
The committee, comprised of representatives from MECON, NISST, Ministry of Ports, Shipping & Waterways, Bureau of Indian Standards, Material Recycling Association of India (MRAI), MSTC Ltd, Ship Recycling Industries Association, and Gujarat Maritime Board, played a crucial role in assessing the feasibility of incorporating ship-breaking steel plates into the production of TMT bars.
On-Site Evaluation:
Members of the committee visited Gujarat’s Alang, recognized as Asia’s largest ship-breaking yard, where they collected samples for analysis. The committee noted that ship sides and bottom plates undergo various types of stress in different directions. However, the collected samples were deemed inadequate in representing hulls at different levels—underwater, mid-ship, or above-water.
Testing and Analysis:
Samples of varying thicknesses were obtained from different shipyards and subsequently rolled into TMT bars of 8 mm, 10 mm, and 12 mm sizes. Laboratory tests were conducted on these finished products. The committee, in its recommendations, emphasized the need for a more extensive dataset to assess the structural integrity of TMT bars made from ship plates. It highlighted the variation in samples of each diameter, emphasizing the necessity for comprehensive studies on the behavior of beams, columns, and joints using these rebars.
Quality Assurance and Durability Studies:
The committee underscored the challenge of directly grading the rebars produced from ship plates. It called for in-depth studies on the long-term durability of these rebars in conjunction with concrete, comparing them with conventional rebars. Corrosion resistance tests were deemed crucial, particularly to determine the suitability of these rebars for wider applications in coastal areas.
Industry Focus on TMT Bars:
During its study, the committee observed a prevailing industry focus on manufacturing TMT bars over other steel products like grills and bars. This preference was attributed to the limited market for alternative products. The data provided by industry associations suggested potential cost savings if the direct rolling of ship plates into TMT bars were permitted.
Cost Considerations:
Industry associations argued that allowing the direct rolling of ship plates into TMT bars could eliminate the melting cost of ₹9,000 per tonne. However, they acknowledged an additional cost of ₹3,000 per tonne when compared to rolling ingots in an automatic TMT mill. Despite this additional cost, a net savings of ₹6,000 per tonne could be achieved by directly rolling reclaimed ship plates into rebars.
Potential Applications of Ship Plates:
Responding to queries from Ministry officials, industry representatives suggested that ship plates could be used in manufacturing thin strips for packaging, small squares, hexagonal and round bars with diameters less than 8 mm, small-size angles, channels, window sections, and more.
Conclusion:
The committee’s rejection of using ship-breaking steel plates for TMT bar production underscores the need for extensive testing and data analysis to ensure the structural integrity, quality, and durability of the resulting rebars. The industry’s focus on TMT bars, driven by market considerations, necessitates a careful examination of the potential cost savings and additional expenses associated with direct rolling of ship plates. Further research and testing are imperative to explore the viability of incorporating reclaimed ship plates into the steel production process, considering the diverse applications and ensuring compliance with quality standards in the construction industry.
