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.

Although Bessemer's father had jokingly suggested using pure oxygen instead of air, this possibility was to remain a dream until "tonnage oxygen" became available at a reasonable cost. A 250 ton BOF today needs about 20 tons of pure oxygen every 40 minutes. Despite its high cost, oxygen was used in Europe to a limited extent in the 1930's to enrich the air blast for blast furnaces and Thomas converters. It was also used in the U.S for scarfing and welding.

The production of low cost tonnage oxygen was stimulated in World War II by the German V2 rocket program. After the war, the Germans were denied the right to manufacture tonnage oxygen, but oxygen plants were shipped to other countries. The bottom tuyeres used in the Bessemer and Thomas processes could not withstand even oxygen-enriched air, let alone pure oxygen. In the late 1940s, Professor Durrer in Switzerland pursued his prewar idea of injecting pure oxygen through the top of the vessel. Development now moved to neighboring Austria where developers wanted to produce low nitrogen, flat-rolled sheet, but a shortage of scrap precluded open hearth operations. Following pilot plant trials at Linz and Donawitz, a top blown pneumatic process for a 35 ton vessel using pure oxygen was commercialized by Voest at Linz in 1952. The nearby Dolomite Mountains also provided an ideal source of material for basic refractories.

The new process was officially dubbed the "LD Process" and because of its high productivity was seen globally as a viable, low capital process by which the war torn countries of Europe could rebuild their steel industries. Japan switched from a rebuilding plan based on open hearths to evaluate the LD, and installed their first unit at Yawata in 1957.

Two small North American installations started at Dofasco and McLouth in 1954. However, with the know-how and capital invested in 130 million tons of open hearth capacity, plans for additional open hearth capacity well along, cheap energy, and heat sizes greater by an order of magnitude (300 versus 30 tons), the incentive to install this untested, small-scale process in North America was lacking. The process was acknowledged as a breakthrough technically but the timing, scale, and economics were wrong for the time. The U.S，which manufactured about 50% of the world's total steel output, needed steel for a booming post-war economy.

There were also acrimonious legal actions over patent rights to the process and the supersonic lance design, which was now multihole rather than single hole. Kaiser Industries held the U.S. patent rights but in the end, the U.S. Supreme Court supported lower court decisions that considered the patent to be invalid.

Nevertheless, the appeal of lower energy, labor, and refractory costs for the LD process could not be denied and although oxygen usage in the open hearth delayed the transition to the new process in the U.S., oxygen steelmaking tonnage grew steadily in the 1960's. By 1969, it exceeded that of the open hearth for the first time and has never relinquished its position as the dominant steelmaking process in the U.S. but the name LD never caught on in the U.S.

Technical developments over the years include improved computer models and instrumentation for improved turn-down control, external hot metal desulfurization, bottom

blowing and stirring with a variety of gases and tuyeres, slag splashing, and improved refractories.

INTRODUCTION

Accounting for 60% of the world's total output of crude steel, the Basic Oxygen Steelmaking (BOS) process is the dominant steelmaking technology. In the U.S., that figure is 54% and slowly declining due primarily to the advent of the "Greenfield" electric arc furnace (EAF)

flat-rolled mills. However, elsewhere its use is growing.

There exist several variations on the BOS process: top blowing, bottom blowing, and a combination of the two. This study will focus only on the top blowing variation.

The Basic Oxygen Steelmaking process differs from the EAF in that it is autogenous, or

self-sufficient in energy. The primary raw materials for the BOP are 70-80% liquid hot metal from the blast furnace and the balance is steel scrap. These are charged into the Basic Oxygen Furnace (BOF) vessel. Oxygen (>99.5% pure) is "blown" into the BOF at supersonic velocities. It oxidizes the carbon and silicon contained in the hot metal liberating great quantities of heat which melts the scrap. There are lesser energy contributions from the oxidation of iron, manganese, and phosphorus. The post combustion of carbon monoxide as it exits the vessel also transmits heat back to the bath.

The product of the BOS is molten steel with a specified chemical anlaysis at 2900°F-3000°F. From here it may undergo further refining in a secondary refining process or be sent directly to the continuous caster where it is solidified into semifinished shapes: blooms, billets, or slabs.

Basic refers to the magnesia (MgO) refractory lining which wears through contact with hot, basic slags. These slags are required to remove phosphorus and sulfur from the molten charge.

BOF heat sizes in the U.S. are typically around 250 tons, and tap-to-tap times are about 40 minutes, of which 50% is "blowing time". This rate of production made the process compatible with the continuous casting of slabs, which in turn had an enormous beneficial impact on yields from crude steel to shipped product, and on downstream flat-rolled quality.

BASIC OPERATION

BOS process replaced open hearth steelmaking. The process predated continuous casting. As a consequence, ladle sizes remained unchanged in the renovated open hearth shops and ingot pouring aisles were built in the new shops. Six-story buildings are needed to house the Basic Oxygen Furnace (BOF) vessels to accommodate the long oxygen lances that are lowered and raised from the BOF vessel and the elevated alloy and flux bins. Since the BOS

process increases productivity by almost an order of magnitude, generally only two BOFs were required to replace a dozen open hearth furnaces.

Some dimensions of a typical 250 ton BOF vessel in the U.S. are: height 34 feet, outside diameter 26 feet, barrel lining thickness 3 feet, and working volume 8000 cubic feet. A control pulpit is usually located between the vessels. Unlike the open hearth, the BOF operation is conducted almost "in the dark" using mimics and screens to determine vessel inclination, additions, lance height, oxygen flow etc.

Once the hot metal temperature and chemical analaysis of the blast furnace hot metal are known, a computer charge models determine the optimum proportions of scrap and hot metal, flux additions, lance height and oxygen blowing time.

A "heat" begins when the BOF vessel is tilted about 45 degrees towards the charging aisle and scrap charge (about 25 to 30% of the heat weight) is dumped from a charging box into the mouth of the cylindrical BOF. The hot metal is immediately poured directly onto the scrap from a transfer ladle. Fumes and kish (graphite flakes from the carbon saturated hot metal) are emitted from the vessel's mouth and collected by the pollution control system. Charging takes a couple of minutes. Then the vessel is rotated back to the vertical position and lime/dolomite fluxes are dropped onto the charge from overhead bins while the lance is lowered to a few feet above the bottom of the vessel. The lance is water-cooled with a multi-hole copper tip. Through this lance, oxygen of greater than 99.5% purity is blown into the mix. If the oxygen is lower in purity, nitrogen levels at tap become unacceptable.

CONCLUSION

The BOS has been a pivotal process in the transformation of the U.S. steel industry since World War II. Although it was not recognized at the time, the process made it possible to couple melting with continuous casting. The result has been that melt shop process and finishing mill quality and yields improved several percent, such that the quantity of raw steel required per ton of product decreased significantly.

The future of the BOS depends on the availability of hot metal, which in turn depends on the cost and availability of coke. Although it is possible to operate BOFs with reduced hot metal charges, i.e. < 70%, there are productivity penalties and costs associated with the supply of auxiliary fuels. Processes to replace the blast furnace are being constantly being unveiled, and the concept of a hybrid BOF-EAF is already a reality at the Saldahna Works in South Africa. However, it appears that the blast furnace and the BOS will be with us for many decades into the future.

The American Iron and Steel Institute acknowledges, with thanks, the contributions of Teresa M. Speiran, Senior Research Engineer, Refractories and Bruce A. Steiner, Senior Environmental Advisor, Collier Shannon Scott PLLC.

氧气转炉炼钢

氧气转炉炼钢工艺的历史

氧气转炉炼钢无疑是“贝塞麦法的衍生”，气动原件过程由爵士亨利柏麦在1856年申请了专利。在那些日子里,因为氧气在商业上是不可用的，空气作为氧化剂。它是通过在梨形容器底部的鼓风口吹入的。由于空气是80％的惰性氮气，进入血管冷，但退出时热，删除这么多的热量,充电过程必须是几乎100％的热金属，因为它是自然发生的。贝塞麦过程无法融化显着数量的废钢成为废钢累计经济的障碍。贝塞麦产生于1906年，在美国达到顶峰，然后徘徊，直到20世纪60年代。

在原来的贝塞麦故事有两个有趣的历史注脚：

于1957年4 大多数欧洲的铁矿石和铁水硫和磷的含量较高，并没有工艺从这些钢中能删除这些，在19世纪60年代这项工艺被开发出来。其结果是，贝塞麦炼钢法同时遭受“热脆性”（由于硫）和“冷脆性”（由于磷），使其韧性差。对于他的第一个商业化的工厂，1866年在谢菲尔德，贝塞麦重熔从瑞典进口的作为原料的冷生铁成铁水。从生铁得到的木炭中磷和硫含量低，（偶然地）以高锰作为脱氧剂。与此相反，美国生铁生产中使用低硫木炭和低磷国内矿石。因此，由于天才的亚历山大华立集团，1866年两个贝塞麦工厂在运作。然而，位于远程的木炭高炉每天的产量是非常低。因此，热金属重熔生铁生产时冲击圆顶，重力供给5吨到贝塞麦容器。

贝塞麦真正的突破发生在1879年的时候，一个来自伦敦警方法院年轻的店员西德尼?托马斯震惊于冶金学的建立,通过一个数据,一种从贝塞麦钢中消除磷（包括硫）的工艺。他开发从焦油结合白云石砖生产的基本内衬。这些被侵蚀形成的碱性渣吸收磷和硫，虽然以现代的标准金额仍然高。欧洲人很快采取“托马斯工艺”，因为他们的高磷铁水，并作为奖金，小颗粒状的富磷熔渣在水中造粒。在美国，当托马斯提出他的论文时,安德鲁?卡内基在场，结识了这位年轻男人并巧妙地获得了美国的许可，这压制了南部炼钢的发展,那里高磷矿石广部。

贝塞麦的父亲虽然曾开玩笑地建议用纯氧代替空气，这种可能性仍然是一个梦想，直到“工业用气”以合理的价格变成可获得的。今天250吨转炉纯氧需要约20吨，每40分钟发一趟车。尽管其成本高，在19世纪30年代的欧洲氧气在有限的范围内使用,以丰富鼓风高炉和托马斯转换器。在美国它也可用于嵌接和

焊接。

生产成本低的工业用氧在第二次世界大战期间德国的V2火箭计划刺激下量产。战争结束后，德国被剥夺吨位制造氧气的权利，但氧植物被运到其他国家。底部风口使用中无法承受富氧空气，更不用说纯氧。在20世纪40年代末，瑞士杜雷尔教授追求他战前的想法，通过容器顶部注入纯氧。发展到现在搬迁到邻近的奥地利开发商想生产低氮，平轧板，但短缺的废料阻碍了平炉操作。在林茨和多纳维茨，经过试验设备测试，于1952年，一个使用纯氧顶吹气动的35万吨级船只商品化，通过位于林茨的霍伊斯特。该附近的白云石山脉也提供了一个理想的来源。

耐火材料新工艺被正式地称为“LD法”，因为其在全球的高生产率被视为可行的，低资本过程使被战争蹂躏的欧洲国家可能会重建自己的钢铁行业。日本从一个重建计划的基础上打开火炉评估劳工处，并于1957年在在八幡安装其首台机组。

在1954年的多法斯科和麦克洛斯，两个小北美安装开始。但是，技术和资本在平炉炼钢能力130万吨被投资，用于额外的平炉炼钢容量的计划，廉价的能源和热量大小大一个量级（300与30吨），安装未经测试的激励,在北美小规模的过程缺乏。这个过程被认定为一个技术上的突破，但当时的时间，规模，经济是错误的。钢制造占世界钢铁总产量的50％左右的美国，需要战后经济蓬勃发展所需的钢材。

在该工艺专利权和超音速枪的设计上，也有激烈的法律行动，这是现在多孔而不是单一的孔的原因。凯撒工业持有美国专利权，但是最终，美国最高法院支持下级法院的决定，认为该专利是无效的。

然而，对较低的能源，劳动力和LD法耐火材料的成本的诉求可能不会被拒绝，虽然氧气在平炉中的使用延迟过渡到新的工艺，在美国，氧气炼钢吨位在20世纪60年代稳步增长。到1969年，它第一次超过了平炉炼钢,在美国从未放弃其作为炼钢过程中占主导地位，但LD的名字从未在美国流行。

多年来的技术的发展，包括改进的计算机模型和仪器，以提高转弯式控制，外部的铁水脱硫，底吹和搅拌各种气体的风嘴，炉渣飞溅，和改进的耐火材料。

介绍

占世界粗钢总产量的60％，碱性氧气炼钢（BOS）的过程中是占主导地位的炼钢技术。在美国，这个数字是54％，并缓慢下降，这主要是由于“松涛”电动电弧炉的到来是熔炉（EAF）平轧钢厂。然而，在其他地方它的使用越来越多。

氧气转炉炼钢存在的几个变化：顶吹，底吹，和两者的结合。这项研究将只专注顶吹变化。

氧气转炉炼钢和电炉炼钢工艺不同，因为它是自然发生的或能自给自足能量的。BOP的主要原材料是70-80％的来自高炉的高温铁水，而且余量是废钢。这些被充入到碱性氧气转炉（BOF）容器。氧气（纯度> 99.5％）以超音速的速度“吹”入转炉。氧化包含在热铁水中的碳和硅，解放大量的热量熔化废钢。来自铁，锰，磷的氧化，有更少的能量贡献。因为它的燃烧产生的一氧化碳后的容器也将热传递到熔池。

氧气转炉炼钢产品钢水指定的化学周期在2900°F-3000°F。从这里可以二次精炼过程中进行进一步的精炼，或直接发送到连铸机凝固成半成品的形状：钢坯，钢坯，或地砖。

碱性指的是氧化镁耐火衬里,它通过接触热，碱性炉渣。这些炉渣需要从浇铸装料中除去磷和硫。

转炉热尺寸在美国通常约为250吨，冶炼周期是40分钟左右，其中50％是“吹炼时间”。这种生产速度使得该工艺和板坯连铸保持一致，这反过来又对粗钢产品出货产量和在下游平轧质量产生了巨大的有利影响。

基本操作

氧气转炉炼钢工艺取代了平炉炼钢。该工艺早于连续铸钢。因此，在改善的平炉车间，钢包大小仍然不变，并且铸锭浇注过道在新的车间被重新建造。六层楼高的建筑物需要容纳碱性氧气转炉（BOF）容器，以容纳长的氧枪，降低和提高转炉容器，高温合金和通量箱。由于氧气转炉炼钢工艺几乎提高产品一个数量级的产量，一般只有两个座转炉须更换十几平炉。

在美国一个典型的250吨转炉容器的一些尺寸是：高34英尺，外径26英尺，内衬厚度为3英尺，工作体积8000立方英尺。一个控制室通常位于转炉容器之间。不像平炉，转炉操作的进行几乎是“在黑暗中”使用模拟和屏幕来确定容器倾斜，添加，喷枪高度，氧气流量等。

当铁水温度和高炉铁水的化学分析已知，一台计算机的负责模式确定最佳比例的废钢和铁水，流量的增加，喷枪的高度和吹氧时间。

当氧气转炉容器向装料过道倾斜约45度时，一个“热”开始了。废钢炉料（约25?30％的热重）充电盒倾倒进入筒状转炉的风口。铁水立即直接从转移钢包浇在废钢上。烟雾和基什（片状石墨的碳饱和铁水）从容器的风口中发出，并收集污染控制系统。装料需要一两分钟。然后，容器旋转到垂直位置，石灰/白云石助熔剂从头顶钢包下降到装料箱，喷枪降低到上述容器的底部几英尺。喷枪用多孔铜端头水冷却。通过这一次喷枪，大于99.5％纯度的氧气吹入混合。如果氧的纯度较低，氮含量变得不可接受的。

结论

自二战以来，氧气转炉炼钢已经成为美国钢铁工业转型中一种重要的工艺。尽管它在当时并没有被确认，但该过程使人们有可能与连续铸造熔融耦合。结果是，车间熔炼工艺和精轧机质量和产量提高几个百分点，例如，每吨产品所需的原料钢的数量显着减少。

氧气转炉炼钢的未来依赖于铁水的可利用性,，它依次取决于对焦炭的成本和可用性. 虽然碱性氧气转炉数量与热金属费用减少是可能的操作，即<70％，有生产率处罚和成本相关联的辅助燃料供应。取代高炉的进程正不断地被揭开神秘面纱，在南非的萨尔达尼工厂,混合转炉电炉的概念已经成为一个现实。但是，似乎高炉和氧气转炉炼钢将会与我们存在很多代人直到未来。

美国钢铁协会答谢，高级研究工程师特丽萨?M?斯佩兰和高级环境顾问布鲁斯?A?斯泰纳做出了巨大的贡献。