大学毕业论文—连铸的发展外文翻译.doc

The Development of Continuous Casting 【连铸】——中英文对照 Continuous Casting From the Making, Shaping and Treating of Steel by William，McGraw—Hill Companies, Inc., 2002 The Development of Continuous Casting Continuous casting was developed very rapidly after the Second World War. Steel-producers arc today generally convinced that continuous casting is at least as economical as ingot production and can match the quality of the latter across much of the production spectrum for high-quality steels. Continual development of the technique aimed at improved steel characteristics is leading to increasing adoption of the process in works producing special high-grade steels. The reasons for continuous-casting systems are: (1) lower investment outlay compared with that for a blooming train (mini-steelworks); (2) about 10% more productivity than with conventional ingot-casting; (3) high degree of consistency of steel composition along the whole length of the strand; better core quality, especially with flat strands; high inherent surface quality, leading to savings on an otherwise expensive surfacing process; (4) high degree of automation; (5) friendlier to the environment; (6) better working conditions. Types of Installation The first continuous-casting plants were aligned vertically; however, with larger cross-sections, increasing strand-length, and, above all, with increasing pouring-rates this type of construction leads to unreasonable building-heights. These factors also lead to a considerable increase in the length of the liquid phase which has metallurgical effects. The length of the liquid phase in a continuously-cast strand is determined by the following formula: L=D2/4x2Vc Where D =strand thickness (mm) x = solidification characteristic (mm / min1/2) These values amount to 26～33 for the whole cooling length. Vc = casting rate (m /min) Efforts to reduce building-height first led to continuous-casting systems in which molten metal passed into a vertical mould and