冶金专业英语翻译.docxVIP

科目专业英语专业冶金工程姓名仲光绪学号 1045562137The Basic Oxygen Steelmaking (BOS) ProcessHISTORY OF THE BASIC OXYGEN STEELMAKING PROCESSBasic Oxygen Steelmaking is unquestionably the son of Bessemer, the original pneumatic process patented by Sir Henry Bessemer in 1856. Because oxygen was not available commercially in those days, air was the oxidant. It was blown through tuyeres in the bottom of the pear shaped vessel. Since air is 80% inert nitrogen, which entered the vessel cold but exited hot, removed so much heat from the process that the charge had to be almost 100% hot metal for it to be autogenous. The inability of the Bessemer process to melt significant quantities of scrap became an economic handicap as steel scrap accumulated. Bessemer production peaked in the U.S. in 1906 and lingered until the 1960s.There are two interesting historical footnotes to the original Bessemer story:William Kelly was awarded the original U.S. patent for pneumatic steelmaking over Bessemer in 1857. However, it is clear that Kellys air boiling process was conducted at such low blowing rates that the heat generation barely offset the heat losses. He never developed a commercial process for making steel consistently.Most European iron ores and therefore hot metal was high in sulfur and phosphorus and no processes to remove these from steel had been developed in the 1860s. As a result, Bessemers steel suffered from both hot shortness (due to sulfur) and cold shortness (due to phosphorus) that rendered it unrollable. For his first commercial plant in Sheffield, 1866, Bessemer remelted cold pig iron imported from Sweden as the raw material for his hot metal. This charcoal derived pig iron was low in phosphorus and sulfur, and (fortuitously) high in manganese which acted as a deoxidant. In contrast the U.S. pig iron was produced using low sulfur charcoal and low phosphorus domestic ore. Therefore, thanks to the engineering genius of Alexander Holley, two Bessemer plants were in operation by 1866. Howev