From the history of steelmaking

F or a thousand years before 1850 man’s entire stock of ferrous metals consisted of cast iron, wrought iron (0) labouriously (labour) made in small quantities at high cost, and a few carbon tool steels made at still (1) …………. (high) cost. Between 1850 and 1860 a series of (2) …………. (invent) allowed furnaces to operate at temperatures high enough to melt iron.

First, in 1856, Henry Bessemer patented his (3) …………. (convert) process for blowing air through molten pig iron, and in 1861 William Siemens (see the picture) (4) …………. (take) out a patent for his (5) …………. (regenerate) open-hearth furnace. The (6) …………. (develop) allowed making steel in quantities large enough and at a cost low enough to begin a century of industrial progress.

For about 100 years the open-hearth and Bessemer-based processes were (7) …………. (joint) responsible for most of the steel produced. Today, more than three-quarters of the world’s steel is melted in the (8) …………. (base) oxygen and electric-arc furnaces.

4.9. Translate into Russian. Pay attention to the infinitive functions.

1. Many devices to measure different properties of substances are used in our laboratories. 2. In order to maintain the quality of a product, temperature and pressure are constantly controlled. 3. Steel undergoes that treatment to improve its structure. 4. The ability of various metals to form alloys differs greatly. 5. This material is easy to machine. 6. The task of a scientist is to explain what is, and the task of an engineer is to create what never was. 7. We were too tired to discuss the matter. 8. He failed to make his point of view. 9. They managed to fulfil the task. 10. To make a choice between these two alloys was quite difficult. 11. The young scientist found it difficult to speak in public. 12. In 1831, Pavel Anosov was the first to use a microscope to analyse the structure of metals. 13. To tell the truth, we expected quite different results of this experiment. 14. To be sure, a great progress in materials science has been made in the last two decades.

4.10. Study Table 2 and complete the text below using the words from the list.

Table 2

Carbon Content-Tensile Strength and Carbon Content-Hardness Relations for Carbon Steels

Low-Carbon Steel	Mild Steel	Medium-Carbon Steel	High-Carbon Steel
			Hard Steel	Spring Steel	Tool Steel
T ENSILE STRENGTH HARDNESS
0.15	0.25	0.65	0.85	1.05
% CARBON →

Notes

spring steel – пружинная сталь

tool steel – инструментальная сталь

as, even, tool, weakest, than, above, medium, softest, stronger, however, content, the

Low-carbon steel is not very hard. It is the (1) …… of the steels. Mild steel is harder (2) …… low-carbon steel, and medium-carbon steel is (3) …… harder. The high-carbon steels are the hardest. Hard steel is not (4) …… hard as spring steel, and the hardest is (5) …… steel. Among these common steels, hardness is proportion to their carbon content. The greater their carbon content, (6) …… greater their hardness.

Low-carbon steel is not very strong. It is the (7) …… of the steels. Mild steel is (8) …… than low-carbon steel, and (9) ……-carbon steel is even stronger. The strongest of all are the high-carbon steels. (10) ……, their strength is not always in proportion to their carbon (11) …… . Some tool steels are not as strong as some hard steels. Below 0.85% carbon, the greater their carbon content, the stronger they are. (12) …… 0.85% carbon, the greater their carbon content, the weaker they are.

4.11. Read the text Alloy Steels, answer Grammar and Vocabulary Questionnaire and prepare its summary using the tips in Appendix.