Tasdiqlayman“Chet tiilar” kafedras imudiri M. B. Ganikhanova

Toshkent davlat texnika universiteti “Chet tillar” kafedrasi

Tasdiqlayman“Chet tiilar” kafedras imudiri M.B.Ganikhanova. ___________ -сонли баеннома/ / /20 й.

_____ guruh talabasi______________ning ingliz tili fani bo’yicha yakuniy nazorat ishi Sana___________

VARIANT X

Translate the sentences

1. Machine parts are subjected to x-ray examination.

2. We were shown a number of experiments illustrating the presence of high-energy particles in the cosmic radiation.

3. Many power plants are being built in our country.

4. The atomic power has been applied to all fields of man’s civilian activity.
Make the questions for each sentence

1. Some substances do not conduct heat.

2. These computers will have to perform millions of operations per second.

3. Mechanization is to be distinguished from more primitive tool using.

4. Metals conduct electricity better than semiconductors do.
Read and translate the text.

Annealing

Annealing involves heating to and holding at a suitable temperature, followed

by cooling at an appropriate rate, primarily for softening of metals. When annealing iron-based alloys, the work is 50 to 100°F above the critical temperature range. The alloy is held for a period of time to insure uniform temperature throughout the part, and then allowed to cool slowly by keeping the parts in the furnace and allowing both to cool . The cooling method should not permit one portion of the part to cool more rapidly than another portion. Its purpose is to remove stresses;

induce softness; alter ductility, toughness, and magnetic properties; change grain size; remove gases; and produce a definite microstructure.

Steel is annealed for one or more of the following reasons:

• 
  To soften it for machining or fabrication operations;
  
• 
  To relieve stresses in the material (often necessary after casting or welding operations);
  
• 
  To alter its properties;
  
• 
  To condition the steel for subsequent heat treatments or cold work;
  

To refine grain size, improve ductility and promote dimensional stability.