43. Основываясь на содержании текста е, ответьте по-английски на следующие вопросы

1) What types of molding sand is this text about?

2) What sands must be fine (coarse)?

3) Is bond used for light, medium and heavy sands?

4) What material is used as a band?

5) When is heavy sand used?

44. Подумайте, как можно озаглавить текст е.

45. Прочтите текст f, переведите его и ответьте по-английски на следующие вопросы

1) What are the two large groups of casting metals?

2) What alloys do ferrous alloys include?

3) What cast metal is the most important among the ferrous metals?

4) From what material is it made?

5) Is cast iron very strong? Why?

6) Is the melting point of cast iron low or high?

7) Is it economical to produce large machine parts from cast iron?

8) What alloys do the non-ferrous cast metals include?

Text f casting metals

There are two large groups of casting metals: the ferrous metals and non-ferrous metals. Foundries mix the relatively pure metals to produce necessary alloys. The ferrous or iron alloys include all the cast irons, carbon steels and alloy steels.

Among the ferrous metals cast iron is the most important cast material used in the manufacture of products necessary in everyday life. It is made from pig iron by remelting it in the cupola. When the pig iron has been remelted in the cupola, its carbon content is reduced. It contains already from 2 to 5 percent carbon. The more carbon the iron contains, the more brittle it is. That is why the brittleness of cast iron is very high.

So, cast iron is not a very strong material, it is not plastic. But it has a low melting point and is the cheapest, the most economical. It is often used for making objects and machine parts which are to be large but the strength of which is not very important.

The non-ferrous metals used in the foundry are usually alloys of two or more metals. They are copper-base, aluminium-base, zinc-base alloys and some others. All these metals have a lower melting temperature then iron alloys.

Notes to the text F:

to include – включать, содержать в себе

alloy steel – легированная сталь

pig iron – доменный чугун, сырцовый (чушковый) чугун

to reduce - восстанавливать

percent - процент

brittle - хрупкий

base – основа

46. Перескажите текст f по-английски. Part III making a sand mold

1. Прочтите, что обозначают следующие слова и словосочетания. Запомните их

to pack – утрамбовывать, уплотнять, набивать

f.e. We must pack the molding sand for making a sand mold.

f.e. Packing the sand is a very important operation in making a sand mold.

wood – дерево

wooden – деревянный

wax – воск, восковой

f.e. There are wooden, metal and wax patterns.

f.e. Patterns may be made of wood, metal or wax.

solid – цельный, неразъемный, монолитный, сплошной

split – разъемный, составной, состоящий из двух частей

f.e. There are two types of patterns: solid and split patterns.

f.e. Cores may be solid and split.

to shrink – давать усадку

f.e. Molten metal shrinks when it cools.

f.e. All metal castings shrink while they are cooling and solidifying.

upper – верхний

lower – нижний

f.e. If the mold is split, it has the lower part and the upper part.

f.e. A split pattern consists of two parts: lower and upper part.

flask – опока

f.e. Flasks may be wooden or metal.

f.e. Flask is a box for making a sand mold.

f.e. Flask contains the pattern and the molding sand.

cope – 1) верхняя опока; 2) изготовленная в верхней опоке литейная форма (верхняя полуформа)

drag – нижняя полуопока; нижняя полуформа; нижняя полуопока литейной формы

f.e. Drag is a lower part of the flask.

f.e. The flask consists of cope and drag.

top – верхний; верх

bottom – нижний; низ, дно, основание

board – доска, плита, щиток

molding board – (под) модельная плита

mould board – (под) модельный щиток

bottom board – подопочная плита, доска

f.e. Molding board is a board necessary in producing a sand mold.

f.e. Two boards must be used in molding- mould board and bottom board.

to place – помещать, ставить, располагать

f.e. Before packing the sand a pattern must be placed into the flask.

to turn over – переворачивать

opening – отверстие

f.e. The molten metal is poured into the mold through the opening in the upper mold.

parting surface – стыковая поверхность; поверхность стыка; поверхность разъема

joint – стык; разъем

f.e. Parting surface is the surface between two halves of the mold when they are joined together.

parting sand – разделительный песок; припыл

f.e. Parting sand is fine sand which is dusted over (посыпать) the mold surface.

vent hole – вентиляционное отверстие для выпуска воздуха или газа

f.e. Small vent holes are usually made on the surface of the cope.

f.e. They are made in several places.

steam – пар

f.e. Steam is produced in the mold by contact of the molten metal with the sand.

f.e. Steam is formed in the mold cavity during the pouring process.

escape – выпуск; выход; удаление

to escape – улетучиваться; выходить; удалять

f.e. It is necessary that the gases and steam escape from the mold.

f.e. Vent holes are made in the mold for the escape of the air, gases and steam.

properly – как следует, должным образом, правильно

f.e. Sand mold must be properly prepared.

to ram – утрамбовывать; набивать

f.e. In large production of molds the sand is rammed with special machines.

to allow – позволять, разрешать

f.e. Cores allow to produce a casting with a hole.

f.e. Vent holes allow the gases to escape from the mold.

pouring basin – литниковая чаша; воронка

gate sprue – вертикальный литник; стояк в литейной форме

runner – литник; литниковый ход; горизонтальный литниковый канал между стояком и питателями; прибыль (в отливках)

gate – 1) литник; 2) питатель (канал литниковый системы, подводящий металл к отливке)

riser – прибыль (отливки); выпор

f.e. Pouring basin, gate sprue, runner, gate and riser are necessary parts of gating system.

f.e. Pouring basin is made on the top of the cope.

f.e. Some gates may be made in the mold.

f.e. Gates may be of different types.

supply – подвод; питание; подача

to supply – подавать; подводить; питать; поставлять