毕业论文外文翻译--金属热处理（适用于毕业论文外文翻译+中英文对照）.doc

模板 1:2010 届本科专业外文文献翻译 Heat treatment of metal 金属热处理姓名刘滕宝学号 200615840114 年级 2006 专业机械设计制造及其自动化系(院) 工学院指导教师王宁宁 2010 年 01月临沂师范学院本科专业职业生涯设计外文文献翻译 1 Heat treatment of metal In industry today there are more than a thousand different metals being used to manufacture products. The modern automobile has more than one hundred different metals used in its construction. An attempt will be made in this passage to give an understanding of the basic classification of metals. Metals were formerly thought tobe those elements that had a metallic luster and were good conductor of heat and electricity. Actually, metals are generally defined as those elements whose hydroxides from bases (such as sodium or potassium).the nonmetals ’ hydroxides from acids (such as sulphur). Metals may exist as pure elements. When two or more metallic elements bined,they form a mixture called an alloy The term alloy is used to identify any metallic system. In metallurgy it isa substance, with metallic properties, that posed of two or more elements, in t imately mixed. Of these elements one must bea metal. Plain carbon steel, in the sense, is basically an alloy of iron and carbon. Other elements are present in the form of impurities. However, mercial purposes, plain carbon steel isnot classified as an alloy steel. Alloy maybe further classified as ferrous and nonferrous. Ferrous alloys contain iron. Nonferrous alloys donot contain varieties of iron and steel are alloys. The ordinary steels are thought of as iron-carbon alloys. However, practically all contain silicon and manganese as well. In addition, there are thousands of recognized alloy steels. Examples are special tool steels, steels for castings, forgings, and rolled shapes. The base metal for all these is iron. Steels are often called by the principal alloying element present. Examples are silicon steel, manganese steel, nickel steel, and tungsten steel. Even nonferrous alloys may contain iron ina small amount, as impurities. Some of th