The heat treatment to which the steel wire containing > 0.25% carbon is subjected to is___________________?

Related Mcqs:

1. Steel containing low percentage of nickel, chromium & tungsten are termed as the _____________ steel ?

   A. Wrought
   B. Tool
   C. Alloy
   D. Plain carbon

2. Maximum heat dissipation occurs from a steel wire (k = 0.5 W/m. k) of 15 mm diameter exposed to air (h = 20W/m2 .k), when the insulation thickness is ________________ mm?

   A. 15
   B. 25
   C. 10
   D. 30

3. For the irreversible reaction, Ca+ 2C = Ca C2 , Δ H°298 = – 60000 J . mole-1 . If a system initially containing 2 moles of calcium, 3 moles of carbon and 1 mole of calcium carbide is allowed to react to completion, the heat evolved at 298 K will be__________________?

   A. 30,000 J
   B. 60,000 J
   C. 90,000 J
   D. 2,40,000 J

4. The minimum carbon content in steel should be ____________________ percent for it to respond to a hardening treatment ?

   A. 0.2
   B. 0.4
   C. 0.6
   D. 0.8

5. Which of the following are made out of the carbon steel having carbon content of 0.9 to 1%?

   A. Small punches, broaches reamers and springs
   B. Cutlery, screws, rivets and files
   C. Mandrels, twist drills, small lathe tools and razors
   D. Forgings like can shaft, structural steel plate, threading dies and drawing dies

6. Eutectoid composition of carbon steel at room temperature is___________________?

   A. Cementite
   B. Pearlite
   C. Martensite
   D. Ferrite

7. ____________________ are normally subjected to sub-zero treatment?

   A. Highly stressed parts
   B. Gauges or precision parts
   C. Cold rolled sheets
   D. Non machinable materials

8. A cylindrical rod subjected to a tensile strain within the elastic limit undergoes a volume change. If the volume strain is equal to half the tensile strain, then the Poisson’s ratio of the rod is___________________?

   A. 0
   B. 0.33
   C. 0.44
   D. 0.25

9. To improve the machinability of steel, it is generally subjected to _____________________?

   A. Spheroidising
   B. Tempering
   C. Normalising
   D. Annealing

10. Sub zero treatment of steel is done to____________________?

    A. Suppress martensite transformation
    B. Enhance its working performance in sub zero atmosphere
    C. Reduce the retained austenite in hardened steel
    D. Induce temper brittleness after its hardening