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Show Table 4 - Summary of potential Reductions in 1984 Natural Gas Use Due to Process Changes or Innovations Base case conventional continuous casting Ingot casting Emerging technologies/processes Continuous casting with 25 percent hot charging Ingot casting with 90 percent direct roll Thin strip (only less than 0.05") Thin strip (including all greater than 0.5") Thin slab (approximately I") Estimated natural gas used1 (106 Btu/ raw ton) 3.4 2.4 3.3 1.2 1.5 1.5 1.5 Applied Total Potential tonnage of natural gas natural steel (106 consumption1 gas 10ssl raw tons) (10 12 Btu) (10 12 Btu) 36.7 124.8 55.8 133.9 36.7 121.1 3.7 55.8 67.0 66.9 31.02 46.5 54.5 46.82 70.1 81.3 51.7 2,3 77 .6 91.2 l Inc l udes natural gas used in processes prior to reheating that may be affected by process change (e.g., ladle preheating, soaking pits). 2Based on 1984 proportions of ingot and continuous cast steel. 3Assumes process yields equivalent to those projected for thin strip casting. Adapted from reference (4). cut annual natural gas consumption by 47.2 and 91.2 x 1012 Btu, respectively (see Table 4). In the past, the U.S. steel industry has been slow to embrace technological change. However, the findings clearly indicate that those companies dedicated to maintaining, and possibly enhancing, market share in a highly competitive world market are now more responsive to technological change that increases productivity. Nonetheless, such changes may significantly decrease the role of steel reheat, and that of natural gas-fueled reheat in particular, over the next 20 years. Mini-mills may account for an additional 5-10 percent of domestic steel production over the next decade at the expense of the integrated mills' market share. Although mini-mills tend to use large amounts of electricity in remelt furnaces, natural gas is currently the preferred fuel for steel reheat. In addition, this natural gas market is enhanced by the fact that mini-mills do not rely on coke, thereby eliminating the competition represented by coke oven gas (and other was te fue Is) that exists in larger BOF-based steel mills (i.e., integrated mills). However, locating mini-mills in areas of relat i ve ly low ut iIi ty e lectrici ty prices may reduce the competitive advantage that natural gas has over electricity in reheat applications. In comparison to integrated mills, minimills are also more likely to adopt hot charging, direct rolling, thin steel casting, and other new technologies that minimize reheat because of their better financial health, their more aggressive attitude toward modernization, and the comparative 299 cost and ease with which these technologies can integra te wi th exis t ing mini-mi 11 equipment and practices. In addition to the unavoidable overall steel reheat market decline, the technological competitiveness of natural gas-based technologies in the remaining reheat market may also be threatened. As the structural and technological changes discussed above move the steel industry toward more continuous, hot-charged processes, the form of reheat required will also change. Future reheat technologies will be required to efficiently boost the temperature of hot-charged workpieces and reheat cooler workpiece edges and corners in a rapid, continuous process. In addition, future reheat technologies must be able to handle relatively thin products such as those coming from thin steel casting processes. Today, electric induction reheat is considered to be the most compatible technology to future reheat needs because of its easier temperature control, higher efficiencies, rapid reheat times, and ease in handling thin materials. CONCLUSIONS There is very little that the gas industry can do to prevent the expected decline of steel reheat as it is commonly used today. Structural changes within the industry will be dictated by the marketplace. However, the gas industry can support technological research and development aimed at improving steel reheat productivity (i.e., increasing energy efficiency, minimizing material losses, |