Exercises

1. Learn the new words and word combinations:

consumable -той, що плавиться

blast furnace jacket -кожух доменної печі

layer of a solid flux -шар твердого флюсу

to interrupt -переривати

leap -стрибок

source of heat -джерело тепла

pool of a liquid current -ванна рідкого

conductive slag електропровідного шлаку

feasible -можливий

welding wires -зварювальні дроти

welding gap -зварювальний зазор

billet -заготівка

in one pass -за один прохід

ingot -зливок

mould -ливарна форма

achievement -досягнення

application -застосування

new in essence -принципіально новий

casting -лиття

bifilar scheme -біфілярна схема

cross-section -поперечний переріз

2. Read and translate the text.

3. Give the antonyms to the words.

Consumable, successful, long time, under, solid, later, heat, high, thick, liquid, conductive, more, new.

4. Answer the following questions:

1. When was the electro-slag welding founded?

2. What are the characteristic features of ESW?

3. What is the source of heat in ESW?

4. What is electro-slag re-melting?

5. What were the 2 new applications developed in Paton Institute?

6. Are there any benefits of the ESW?

5. Make the nouns from the verbs.

To melt, to fuse, to cool, to produce, to weld, to join, to achieve, to cast, to maintain, to introduce.

6. Combine two sentences in one using the proper linking words (relative pronouns/relative adverbs).

1. We came in. He was cleaning the welding joint.

2. They designed a new electrode. It offers longer arc time.

3. The engineers of our laboratory use modern types of torches and burners. They provide high quality welds.

4. We visited an exhibition of welding equipment. We saw new types of electrodes.

5. I prefer stainless electrodes. They offer higher deposition rate.

7. Put all possible questions to the sentences.

1. The electric arc process of consumable electrode melting has successfully been used in welding practice for about 100 years.

2. The ESW marked a revolutionary leap in the field of thick metal welding.

3. Great changes were achieved by the process of electroslag re-melting.

4. The theoretical and practical achievements of the ESR have brought about a new qualitative leap in the development of electro slag welding process.

5. In 1969-70 the Paton Electric Welding Institute developed two more applications new in essence.

8. Combine the following words to get proper terms:

consumable billets

vertical section

molten arc

slag flux

welding electrode

bifilar position

steel metal

weld pool

open wires

solid scheme

9. Complete the questions on the text

1. Did/Was ______?

2. ___or____?

3. _________didn’t/wasn’t ?

4. When/Why/Where?

5. Who/What______?

10. Communicative situations:

1. Make a report on the topic “ ESW-the revolutionary leap in the thick metal welding”

2. Make up a dialogue on the topic “ Benefits of the ESW”.

11. Retell the text.

Text c ultrasonic welding

It should be emphasized that ultrasonic welding is totally unlike the better-known fusion, diffusion and deformation welding processes. Because of certain similarities in equipment and in application of ultrasonic and resistance welding, it is sometimes difficult to appreciate that the welds are actually very dissimilar and cannot always be evaluated by the same yardstick.

The ultrasonic weld is devoid of cast structure, even though some heat is known to be generated during the welding process. The metallurgical bond is between the cladding layers, while the substrate layers appear unaffected. There is not sheet separation at the edges of the bond zone, and thickness deformation is negligible.

Vibratory welds in the aluminium alloys show slightly different characteristics. Depending on the alloy there may be marked disturbance and disruption at the interfacial plane, or grain growth or crystallization may occur across the surfaces.

Review of tensile strengths for aluminium alloys indicates ultrasonic welds to be superior to resistance spot welds within the range of presently weldable gases, and it appears that extension of the process to heavier material depends only on increasing the power-handling capacity of the equipment.

A further advantage of ultrasonic welding over other types of metallurgical joining is that surface preparation is less exacting. For aluminium alloys, it is necessary only to remove surface grease and oils.

The equipment for ultrasonic welding differs from resistance units in several fundamental respects. The controls are comparatively simple. Once the equipment is turned on, any type of aluminium alloy may be welded by adjustment of only three settings – power, clamping force and pulse time. Thus, in a productive setup, the equipment may be easily operated by inexperienced personnel. In contrast, a resistance welding maсhine may have 25 or more controls that require adjustment and must be handled by skilled operator. Furthermore, the power requirements for ultrasonic welding of aluminium are substantially less than for resistance welding. Thus expensive power installations are not required for ultrasonic welding equipment.