冶金专业英语翻译

科目专业英语

专业冶金工程

姓名仲光绪

学号1045562137

HISTORY OF THE BASIC OXYGEN STEELMAKING PROCESS

Basic 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 Kelly's "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, Bessemer's 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. However, the daily output of remotely located charcoal blast furnaces was very low. Therefore, hot metal was produced by remelting pig iron in cupolas and gravity feeding it to the 5 ton Bessemer vessels.

The real breakthrough for Bessemer occurred in 1879 when Sidney Thomas, a young clerk from a London police court, shocked the metallurgical establishment by presenting data on a process to remove phosphorus (and also sulfur) from Bessemer's steel. He developed basic linings produced from tar-bonded dolomite bricks. These were eroded to form a basic slag that absorbed phosphorus and sulfur, although the amounts remained high by modern standards. The Europeans quickly took to the "Thomas Process" because of their very high-phosphorus hot metal, and as a bonus, granulated the phosphorus-rich molten slag in water to create a fertilizer. In the U.S., Andrew Carnegie, who was present when Thomas presented his paper in London, befriended the young man and cleverly acquired the U.S. license, which squelched any steelmaking developments in the South where high phosphorus ores are located.