_ / Матер_али на практичн_ заняття / 3semester / 3.fundamentals of casting practice

FUNDAMENTALS OF CASTING PRACTICE

1. Casting is based on the use of one of the physical properties of liquids. This property consists in the ability of a liquid to take the shape of the vessel it is poured into (under the force of gravity).

2. Metals and alloys heated to a temperature exceeding the melting point become liquid. When cooled, liquid metal or alloy, poured into a vessel, solidifies. The solidified metal will keep the shape of the vessel into which it was poured in liquid state. After the vessel is broken, its shape is kept by the solidified metal. Thus, by using vessels of different shapes, castings of different configurations can be obtained from liquid metals.

3. In blanks production by casting this role is played by foundry mould. The parts of a mould are normally fabricated separately and assembled afterwards. Inside the mould there is a cavity, which has the shape of the blank required. This cavity is filled with molten metal through gating arrangement.

4. The starting material for producing an iron or steel melt are foundry and conversion pig, cast-iron and steel scrap, chips, ferro-alloys and non-metallic materials such as fuels and fluxes.

5. Various melting furnaces are available to melt and overheat ferrous and non-ferrous metals and alloys. Shaft-type furnaces, called cupolas, provide for molten cast iron; electric and open-hearth furnaces for steel, and flame furnaces for cast iron and non-ferrous alloys.

6. To obtain the required structure and mechanical properties of castings and to relieve internal stresses, the cast pieces are often subjected to heat treatment-heating and cooling in ovens strictly to the prescribed schedule (the time and temperature of treatment).

Task 1.

Memorise the following words and word combinations

blank	заготівка
mould	ливарна форма
gating arrangement	ливникова система
cast-iron	чавун
steel scrap	стальний брухт
shaft-type furnace	шахтна піч
open-heart furnace	мартенівська піч
flame furnace	полум’яна піч

Task 2.

Find in the text English equivalents to the following words and word combinations:

литво, ливарне виробництво, фізичні властивості, механічні властивості, виготовляти, форма, точка плавлення, сила тяжіння, сплав, охолоджувати, твердіти, раковина, збирати, вихідний матеріал, флюс, вагранка, внутрішнє напруження, термічна обробка, режим (графік).

Task 3.	Match the words from column A with the Ukrainian equivalents from column B:
А		В
casting property liquid ability gravity alloy vessel blank mould cavity melt scrap chips fuels oven schedule		заготівка графік тяжіння стружка піч лиття розплав здатність порожнина брухт сплав ливарна форма пальне властивість посудина рідина

Task 4.

Make up word combinations and translate them:

physical	metal
melting	mould
solidified	melt
liquid	production
blank	stresses
foundry	materials
gating	materials
starting	properties
steel	furnace
non-metallic	treatment
melting	state
open-hearth	furnace
internal	point
heat	arrangement

Task 5.

Give Ukrainian equivalents to the following words and word combinations:

casting, foundry, to take the shape, to keep the shape, under the force of gravity, the solidified metal, melting point, castings of different configurations, liquid metal, blank production, foundry mould, separately, afterwards, the blank required, molten metal, various furnaces, cupola, to relieve internal stresses, the cast pieces, strictly to the prescribed schedule.

Task 6.

Find in the text antonyms to the following words:

solid, to cool, the same, prior to, outside, metallic, unavailable, ferrous, crystallize.

Task 7.

Fill in the gaps with the missing words:

1. Casting ______ on the ability of a liquid to take the shape of the vessel it is poured into.

2. When metals ______ they become liquid.

3. Liquid metal ______ into the vessel.

4. The cavity inside the vessel ______ with molten metal through gating arrangement.

5. When cooled, liquid metal ______.

6. When metal solidifies the vessel ______.

7. The shape of the vessel ______ by the solidified metal.

8. We can ______ castings of different configurations by using vessels of different shapes.

Task 8.

Answer the following questions:

1. What is casting based on?

2. What shape does the solidified metal keep?

3. How can castings of different configurations be obtained from liquid metals?

4. How is the mould made?

5. In what way is the cavity of the mould filled with molten metal?

6. Name the starting material for producing an iron or steel melt.

7. What melting furnaces do you know?

8. What are the cast pieces often subjected to?

Task 9.

Think of the title to each paragraph of the text and write them down.

Task 10.

Retell the text.