Question

Помогите пожалуйста с английским, нужно ответить на вопросы используя текст Text в: «steel» The most important metal in industry is iron and its alloy — steel. Steel is an alloy of iron and carbon. It is strong and stiff, but corrodes easily through rusting, although stainless and other special steels resist corro­sion. The amount of carbon in a steel influences its prop­erties considerably. Steels of low carbon content (mild steels) are quite ductile and are used in the manufacture of sheet iron, wire, and pipes. Medium-carbon steels con­taining from 0.2 to 0.4 per cent carbon are tougher and stronger and are used as structural steels. Both mild and medium-carbon steels are suitable for forging and weld­ing. High-carbon steels contain from 0.4 to 1.5 per cent carbon, are hard and brittle and are used in cutting tools, surgical instruments, razor blades and springs. Tool steel, also called silver steel, contains about 1 per cent carbon and is strengthened and toughened by quenching and tempering. The inclusion of other elements affects the properties of the steel. Manganese gives extra strength and tough­ness. Steel containing 4 per cent silicon is used for trans­former cores or electromagnets because it has large grains acting like small magnets. The addition of chro­mium gives extra strength and corrosion resistance, so we can get rust-proof steels. Heating in the presence of carbon or nitrogen-rich materials is used to form a hard surface on steel (case-hardening). High-speed steels, which are extremely important in machine-tools, contain chromium and tungsten plus smaller amounts of vana­dium, molybdenum and other metals. General understanding: 1. What is steel? 2. What are the main properties of steel? 3. What are the drawbacks of steel? 4. What kinds of steel do you know? Where are they used? 5. What gives the addition of manganese, silicon and chromium to steel? 6. What can be made of mild steels (medium-carbon steels, high-carbon steels)? 7. What kind of steels can be forged and welded? 8. How can we get rust-proof (stainless) steel? 9. What is used to form a hard surface on steel? 10. What are high-speed steels alloyed with?

Answer 1

1. What is steel?

Steel is an alloy of iron and carbon.

2. What are the main properties of steel?

 Steel is strong and stiff.

3. What are the drawbacks of steel?

Steel corrodes easily through rusting.

4. What kinds of steel do you know?

We know stainless steel, low-carbon steels, medium-carbon steels, high-carbon steels and tool steel (silver steel).

Where are they used?

They are used in manufacturing parts and machines for various industries.

5. What gives the addition of manganese, silicon and chromium to steel?

Manganese gives extra strength and tough­ness. Steel containing 4 per cent silicon is used for trans­former cores or electromagnets. The addition of chro­mium gives extra strength and corrosion resistance.

6. What can be made of mild steels (medium-carbon steels, high-carbon steels)?

Low carbon steels are used in the manufacture of sheet iron, wire, and pipes. Medium-carbon steels are used as structural steels. Both mild and medium-carbon steels are suitable for forging and weld­ing. High-carbon steels are used in cutting tools, surgical instruments, razor blades and springs.

7. What kind of steels can be forged and welded?

Mild and medium-carbon steels are suitable for forging and weld­ing.

8. How can we get rust-proof (stainless) steel?

We can get rust-proof steels by adding chro­mium to steel.

9. What is used to form a hard surface on steel?

Heating in the presence of carbon or nitrogen-rich materials is used to form a hard surface on steel.

10. What are high-speed steels alloyed with?

High-speed steels are alloyed with chromium and tungsten plus smaller amounts of vana­dium, molybdenum and other metals.

Answer 2

1. Steel is an alloy composed of iron and carbon.

2. The main properties of steel are its strength and stiffness. It is also resistant to corrosion, although certain types of steel, such as stainless steel, have even greater resistance to corrosion.

3. The main drawback of steel is that it easily corrodes through rusting. However, this can be mitigated by using stainless steel or other special steels that resist corrosion.

4. There are several kinds of steel:

• Mild steels, which have low carbon content and are ductile. They are used in the manufacture of sheet iron, wire, and pipes.
• Medium-carbon steels, which contain 0.2 to 0.4 percent carbon and are tougher and stronger. They are used as structural steels and are suitable for forging and welding.
• High-carbon steels, which contain 0.4 to 1.5 percent carbon and are hard and brittle. They are used in cutting tools, surgical instruments, razor blades, and springs.
• Tool steel (silver steel), which contains about 1 percent carbon and is strengthened and toughened by quenching and tempering.
• High-speed steels, which contain chromium, tungsten, and smaller amounts of vanadium, molybdenum, and other metals. They are important in machine-tools.

5. The addition of manganese to steel gives extra strength and toughness. Steel containing 4 percent silicon is used for transformer cores or electromagnets because it has large grains that act like small magnets. The addition of chromium gives extra strength and corrosion resistance, resulting in rust-proof steels.

6. Mild steels can be used to manufacture sheet iron, wire, and pipes. Medium-carbon steels are suitable for forging and welding, and they are commonly used as structural steels. High-carbon steels are used in cutting tools, surgical instruments, razor blades, and springs.

7. Both mild steels and medium-carbon steels are suitable for forging and welding.

8. Rust-proof (stainless) steel can be obtained by adding chromium to the steel. Chromium provides extra strength and corrosion resistance, resulting in a steel alloy that resists rusting.

9. A hard surface can be formed on steel through a process called case-hardening. This process involves heating the steel in the presence of carbon or nitrogen-rich materials.

10. High-speed steels are alloyed with chromium and tungsten, and they may also contain smaller amounts of vanadium, molybdenum, and other metals. These alloys are essential in machine-tools.