Test: Cold Working, Recrystallisation, Rolling & Forging - 1 - Mechanical Engineering MCQ

Assertion (A): To obtain large deformations by cold working intermediate annealing is not required.
Reason (R): Cold working is perfol1ned below the recrystallisation temperature of the work material. 

Consider the following statements: 
When a metal or alloy is cold worked
1. it is worked below room temperature.
2. it is worked below recrystallisation temperature.
3. its hardness and strength increase.
4. its hardness increases but strength does not increase. 

Q.

Of these correct statements are

Assertion (A): In case of hot working of metals, the temperature at which the process is finally stopped should not be above the recrystallisation temperature.
Reason (R): If the process is stopped above the recrystallisation temperature, grain growth will take place again and spoil the attained structure. 

Consider the following statements:
In comparison to hot working, in cold working,
1. higher forces are required
2. no heating is required
3. less ductility is required
4. better surface finish is obtained

Q. Which of the statements given above are correct? 

Assertion (A): Cold working of metals results in increase of strength and hardness
Reason (R): Cold working reduces the total number of dislocations per unit volume of the material 

Cold working of steel is defined as working 

In metals subjected to cold working, strain hardening effect is due to 

Specify the sequence correctly 

Assertion (A): While rolling metal sheet in rolling mill, the edges are sometimes not straight
and flat but are wavy. [IES-2003]
Reason (R): Non-uniform mechanical properties of the flat material rolled out result in waviness of the edges.

Which of the following assumptions are correct for cold rolling?
1. The material is plastic.
2. The arc of contact is circular with a radius greater than the radius of the roll.
3. Coefficient of friction is constant over the arc of contact and acts in one direction
throughout the arc of contact.

Q.

Select the correct answer using the codes given below:Codes:

In the rolling process, roll separating force can be decreased by 

Consider the following statements:
1. Forging reduces the grain size of the metal, which results in a decrease in strength and toughness.
2. Forged components can be provided with thin sections, without reducing the strength. 

Q.

Which of the statements given above is/are correct?

Which one of the following manufacturing processes requires the provision of ‘gutters’? 

In open-die forging, disc of diameter 200 mm and height 60 mm is compressed without any barreling effect. The final diameter of the disc is 400 mm. The true strain is

Consider the following statements:
Roll forces in rolling can be reduced by
1. reducing friction
2. using large diameter rolls to increase the contact area.
3. taking smaller reductions per pass to reduce the contact area. 

Q.

Which of the statements given above are correct?

Assertion (A): Forging dies are provided with taper or draft angles on vertical surfaces.
Reason (R): It facilitates complete filling of die cavity and favourable grain flow. 

In rolling a strip between two rolls, the position of the neutral point in the arc of contact doesnot depend on