UnitFromtheHistoryofIronmakingandSteelmaking冶金专业英语.ppt

Unit 1 From the History of Ironmaking and Steelmaking 钢铁工业是世界上最重要的工业之一，也是传统史上最古老的工业之一。早在公元3000年前，铁就是人类文化与文明的基础。 Worldwide, the iron and steel industry is one of the most significant and, in terms of tradition, one of the oldest sectors of industry. As early as 3,000 years ago, iron was serving as a basis of human culture and civilization. The beginning of the extraction of iron from its ores dates back to prehistoric times. In early times, iron ore was heated in a charcoal fire (doubtless by chance at first). When the fire went out, a piece of solid iron like a sponge was left. The spongy iron could be hammered into shape to make tools and weapons. Our metallurgical forefathers found that when they blew or fanned the flames, the fire became hotter and the iron was produced more rapidly, so bellows were used to increase the supply of air. The development of modern ironmaking production benefits from the application of several important techniques: Oxygen steelmaking processes are concerned mainly with the refining of a metallic charge consisting of hot metal (molten pig iron) and scrap through the use of high-purity oxygen to rapidly produce steel of the desired carbon content and temperature. Various steelmaking fluxes are added during the refining process to reduce the sulphur and phosphorus contents of the metal bath to the desired level. The oxygen top-blown process (LD or LD/AC) is currently the more common, but is gradually giving way to combined blowing process in some new plants. 1.Hardening (1) In 1709, Abraham Darby, a yang man succeeded in smelting iron with coke. This innovation resulted in a steep rise in pig iron production. (2) After the year 1755，steam engines and large electric motor were used as blast momentum to force more air into the hearth increasing blast volume greatly. (3) In 1828, Nilson adopted the regenerative hot blast stove to heat air for blast furnace , reducing the coke r