Thermo Mechanical Treatment (TMT) process for reinforcement bars is opening up new vistas in composite RCC, the re-enforcing steel is the costliest constituent (30 to 40% Per Cu. M. of concrete). This cost can be substantially reduced by using higher grades of steel re-enforcing bars. The higher yield strength of re-bars lowers the steel requirement, which results in reduced cost of construction. In India, high strength re-bars of yield strength up to 500 N/sq. mm. are produced either by cold twisting or micro-alloying or a combination of both which adds considerably to the cost of the re-enforcement bars. During the last 30 years, high strength cold twisted deformed bars with yield strength of 415 MPa conforming to IS:1786/85 are widely produced and marketed in our country. These cold twisted bars, though in extensive use at present, continue to have inherent problem of inferior ductility, weld-ability and increased rate of corrosion. Production of re-bars by the addition of micro-alloys gives the desired results of high strengths but at a cost, which is prohibitive. The need for reduction in the steel used for concrete re-enforcement has prompted most countries to switch to re-bars of higher yield strengths of 500 and 550 MPa. The need for cutting down the cost of production of high strength re-bars has initiated the involvement of a more economical and competitive process – the Thermo Mechanical Treatment (TMT) Process. The use of Thermo Mechanical Treatment process has not only helped produce re-bars of high yield strength but also having superior ductility, wild-ability, bend-ability, better corrosion resistance and thermal resistance creating a revolution in re-enforcement engineering. The TMT bars are widely used in construction works such as high rise building, industrial structures, flyovers and bridges etc. The Indian iron and steel industry has come to occupy a dominant position in the socio-economic development of the country and it is certainly a matter of pride that India is the 7th largest crude steel-producing nation in the world. After having gone through the highs and lows of business cycles over time, today the Indian steel industry is on the threshold of a major change as it gears up to give substance to an expansion plan that is ambitious by any standard. Joining forces with the ‘Main Producers’ are the ‘Secondary Producers’ as well, whose emergence in the post-liberalized decade in the Indian steel scene had been initially modest but over the years, they have made a significant contribution to the growth of the domestic iron and steel industry, in terms of spread, capacity, production and commodity basket, necessitation thereby, a fresh look at the segment, traditionally labeled as the ‘Secondary’ Producers, under the Indian context. Steel production in India got a momentum with the announcement of the Industrial Policy Resolution of 1956 when three SAIL plants were set up in the public sector in the late 1950s and the fourth in early 1970. These plants along with IISCO (now, a part of SAIL), VISL and TISCO (now Tata Steel Ltd) were the only integrated steel producers till the eighties. Vizag Steel plant/RINL came into production in the early nineties. The 70s saw the emergence of the Secondary sector – small scale steel producers who opted for the scrap-DRI based electric arc furnace/induction furnace routes – to meet primarily local demand. The semi finished ingots/billets produced by this segment, in turn led to the commissioning of a large number of re-rolling units to convert the semi finished steel into bars and rods, to be used mainly by the construction industry. Moving over the Re-rolling segment, challenges include facing the market downs, specially prices and operational factors like high energy consumption. Prospect for future growth may be considered bright, given the pace and scale of infrastructure / construction activities. Such prospects are captured in the projections for the 11th Five Year Plan of the Government of India, which indicates that share of Secondary Producers in total crude steel production would rise from the present below-50% mark to 53% at the end-of the plan period, as the Secondary sector consolidates their position further. The Indian steel industry has ended 2006-07 on a buoyant note, in the backdrop of Indian economy, growing by a projected 9% growth rate. As the steel industry, including the foreign steel giants setting up steel plants in India, prepares to launch their dream projects, the future of steel in India is awaits a new chapter to be written – a phase which would in all likelihood would witness the Secondary Steel sector further increase their dominance and criticality in the overall operations of the Indian iron and steel industry. If we were to pause for a moment to think about the growth of human civilization, we would find that the pace of social and economic growth has been closely linked to the proficiency with which people have been able to use of shape materials. Steel is one of the critical inputs required to sustain the growth of the economy. In fact it is the basic input for all kinds of economic activity. With the sustained growth of the Indian economy, there has also been a remarkable growth of the Steel Industry. The growth of infrastructures, roads and bridges, civil construction projects, and modern town ship complexes will ensure continued demand of TMT bars.
