Task 5. Fill in the gaps with the verbs given below in proper tense form.

to form, to achieve, to taper, to reduce,

to tap, to line with, to pour, to heat, to fill

1. The finished steel ____ from the furnace into a well heated steel ladle of the required capacity.

2. From the ladle the steel ____ into metal moulds to produce ingots or into sand moulds to obtain steel castings.

3. The mould walls ____ to facilitate stripping from the solidified ingots.

4. As the liquid metal poured into the mould cools, its volume ____ thereby leading to shrinkage of the ingot.

5. A shrinkage cavity, or pipe, ____ in the upper central portion of the ingot where the metal continues to be in the molten state for a long time.

6. Hot tops are extensions of the moulds, they ____ a refractory material.

7. In the top pouring of steel each mould ____ with liquid steel separately.

8. A large economy ____ in the continuous casting of steel.

Task 6. Answer the following questions:

1. How does the tapping of steel start?

2. What size should the ladle be?

3. What cross section may the moulds have?

4. Why the mould walls are tapered?

5. Ingots are produced in a wide size range, aren’t they? Which ingots are the most common size?

6. What is the difference between top and bottom pouring? Which of them provides better surface quality of the ingot? And what is the advantage of the other pouring?

7. When does the shrinkage occur?

8. Where is solidification first in the outside or interior part of the ingot?

9. Where a shrinkage cavity is formed? Why?

10. How can the extent of the pipe (shrinkage cavity) be reduced?

11. How can the metal in hot top be heated?

12. What method of casting is widely applied at the plants?

13. Is vacuum casting as widely applied as continuous casting? Why?

Task 7. Put the following sentences into the proper sequence 1-9. Speak about the continuous casting. Start with: The continuous casting of steel is a new method that is being applied at a number of plants.

1. The completely solidified ingot next passes to the gas-cutting trucks.

2. The ingots continue to travel downwards together with the trucks and are cut into billets of definite length.

3. And at last the billets are rolled into sections of the required shape and size.

4. Then the billets are delivered to the store house.

5. Liquid metal runs in a continuous stream from the ladle into the intermediate device.

6. Upon contact with the seeders and water-cooled walls the liquid metal begins to solidify rapidly on the ingot surface.

7. The billets are carried by conveyers over the inspection table.

8. After that liquid metal runs into the water-cooled solidifiers.

9. It welds to the seeders with which it is pulled downwards, out of the solidifier, by rollers.