Steel - A Die Hard Material: Yesterday, Today and Tomorrow

Dr. T.K.Roy

The influence of steel on the economy since the days of Sir Henry Bessemer has been sustained by its intrinsic value such as easy to work and form shapes. It's supreme ability to respond to various treatments to achieve a wide spectrum of mechanical properties such as hardness, tensile strength, balanced combination of ductility and toughness etc. have established its usefulness for large varieties of applications, compared to other metals and materials.

Every metal - product and service in society can only continue to exist, if it can demonstrate its continuing value. Steel has demonstrated its value in 20th century and the expectation is that it will continue for the current millennium also, if not conquered by new materials in the next millennium.

The value of steel produced annually is much above US 2000 billion. Therefore, the market development activities of the steel plants must be oriented towards demonstration of the value of steel to the customers. It must be recognised that steel is not a single material, but a vast range of different materials, continuously evolving in tandem with emergence of applications. For example, more that 80 per cent of steel in the automotive industry did not exist ten years ago. In automotive and in other applications, steel makers are continuously working in collaboration with customers, improving and modifying their products and innovative new steel emerge in the market. In this connection the strategy of POSCO, the world's largest steel producer is worth mentioning. POSCO has set up plant in February 2003 to market tailor welded blanks to help automobile industry to achieve lower production and material costs as well as reduced weight and vibration while increasing engineering flexibility and safety. In 2002 POSCO has developed and produced line pipe steels for oil and gas transportation over long distance in harsh environment. For energy sector, POSCO has developed high-grade silicon steels after acquiring necessary technology in 2002 and has initiated development in manufacturing thin gauge grain-oriented products as well as non-oriented electrical steel sheets in 2003 to meet strong demand of China. The survival and growth strategy of many industries are to mobilise the individual resources for developing high value product for economically attractive marketing to the customers. The examples of USLAC and ULSC to manufacture ultra light steel automotive closures and ultra light steel automotive suspension are noteworthy. These project show that by working together and pooling resources, the steel industry can present a very powerful message that steel has the potential to provide an economic as well as technical and environmental friendly solution for the automotive industry to ensure sustainable development.

Apart from automobiles, which contain almost 60 per cent of metal input as steel, the largest market segment in the world particularly in developing countries is still belonging to construction sector. Adopting different approaches for design and construction, techno-economically, steel is found to be the material of choice for a growing number of new and innovative applications. Among the various construction materials, steel is the second highest input, besides comment. It is widely appreciated that steel reinforcement plays a cortical role in influencing the structural behaviour of members and correct detailing of  reinforcements is imperative if the structures are to fulfill their assigned roles. The world annual turnover in construction sector is more than US $ 3 trillion with an annual growth rate of 6-9 percent. The Indian construction industry accounts for five per cent of the gross domestic product (GDP) against a figure of 6-9 per cent for many countries. It is expected that Indian construction sector will achieve considerable growth in the next five to ten years and will compete with some of the advanced and emerging economies in the Asia Pacific region.

Energy:

The energy - input in steel industry accounts for about two per cent of all energy consumed in major steel producing companies. This is easily understood when one considers that blast furnaces must reach temperatures of over 1600°C to melt iron. For every tonne of steel produced, integrated mills require an average of 19 to 20 GJ. Since energy represents about 15 per cent of the total manufacturing cost of steel, the industry is highly motivated to reduce its energy intensity and has been doing so significantly over the past decade.

Environment:

Recognising the value of steel to the environment, the steel industry must work together in addressing the issue at a global level. There need to be an all-out effort to reduce the green house gases. These are addressed and implemented in many steel plants - large, medium and small to maintain it as a sustainable industry in all respects. Steel makers have achieved major environmental improvement for cleaner production through better maintenance and improved practices, awareness etc. The influence of environment control measures on the steel industry can be assessed from the following facts:

• In a typical year, 15 per cent of the industry's capital investments go to environmental projects
  

• Over 95 per cent of the water used in steel production needs to be recycled.
  

• Maximum steel recycling to save energy equivalents to an annual power demand of more than 18 million houses.
  

• As steel is 100 per cent recyclable; it should be used over and over again without deteriorating to lower quality products.

As the global economy becomes steadily more competitive, the steel industry continually seeks new ways to stay at the forefront of manufacturing technology. It set forth the industry's long term broad economic, energy, and environmental goals. Specifically, four critical areas in the need of research; process efficiency, recycling, environmental engineering, and product development are identified.

The steel industry has to identify its top R & D needs and if required to from cost shared research partnerships to develop the required technologies. For example, more than 40 steel experts representing the entire range of U.S. iron and steel companies participated in the development of The Steel Industry Technology Roadmap. The roadmap clearly identified the specific research and development in R & D areas that must be pursued if the steel industry is to achieve its economic, energy, and environmental goals. For each critical area defined in the vision document, the Technology Roadmap identifies the key technology barriers, discusses the trends driving technology development, summarises the new and emerging technologies, and lists the most critical R & D needs. Detailed background information is provided on each process or technology, and related issues are discussed at length.

It is undoubtedly an essential requirement that steel industry must confirm to adopt new technologies, techno economically attractive in order to remain a sustainable and competitive industry. Despite the capital intensity and longevity of its assets, the steel industry has witnessed an increasing amount of technology innovations in recent years. Steel is still in its relative infancy as a world material. During the last 25 years, 50 per cent of all steel were made and is likely to grow two fold within the next 25 years. Part of the, growth will be realised by improving the under utilised capacity and creation of new capacity to bridge the gap between deemed and supply. This will be done through improved technologies. It is to be noted that rate of technology innovation has been high as steel makers are motivated to reduce costs and improve quality. Technology of the steel industry may be classified into four broad groups as follows:

• radical and major technologies

• incremental technology

• regulatory technology

• developments from other industries

It refers to be a process modification that eliminates or replaces one or more of the current steel making processes or creates an entirely novel option for iron making and steel making. DR is thus a radical iron making change because it is an alternative to the traditional coke oven-blast furnace route. Direct steel making processes are radical changes because they combine several processes into a single reactor. Continuous casting is radical because it replaces ingot and stripping, reheating, and blooming mill operations. Rolling of powders to strip is also radical.

Includes process modifications that improve efficiency, increase production, improve product quality, or lower operating costs. Energy conservation measures and the recycling of waste materials fall into this category.

Refers to environmental technology, relating to add-on systems that do not alter the steel making process. Examples are biological treatment of waste waters, pipeline charging of coke ovens, and fugitive particulate collectors.

These are used in many ways such as analytical and control techniques, transferred to the steel industry. The adoption of coal gasification processes in conjunction with DR represents a type of technology transfer.

Potential technology changes in the new millennium have been deliberated in a number of major steel journals. 

It is undoubtedly a reality that steel is a classic example of supposed sunset industry, but in reality can boast some of the most advanced technologies. The wide spectrum of possibilities has no doubt made steel so vital to mankind and has enabled the Steel Sun to remain brightly visible well above the horizon. No wonder, Nippon Steel President, Akira Chihaya commented that steel has been and will remain a basic material in our lives. The steel industry is not only alive and well in the information society but can be expected to continue expanding.