Heat Treatments 3

COEP
Lets Crack Online Exam

Subject: Heat Treatments

ITI Trade: Fitter, Turner, Machinist

 

Part 3: List for questions and answers of Heat Treatments                                                             

 

Q1.Which one of the following groups of quenching media is in order of their severity of the cooling rate, i.e. from slow to rapid cooling ? 

a) Oil, forced air, brine solution 

b) forced air, oil, brine solution

c) Brine solution, oil, forced air 

d) Forced air, brine solution, oil 

 

Q2.One component of C50 steel is heated to 830°C, soaked it for some time and then quenched in oil. Again it is heated to 600°C and quenched in oil. Name this process of heat treatment. 

a) Annealing 

b) Normalizing 

c) Hardening and tempering 

d) Case hardening 

 

Q3.The purpose of heat treatment is 

a) To change the mechanical properties of steel 

b) To change the internal structure of steel 

c) To change the appearance of the component 

d) To change the chemical properties of steel 

 

Q4.A approximate hardness of HSS milling cutter is 

a) 45 HRC 

b) 52 HRC 

c) 62 HRC 

d) 75 HRC 

 

Q5. Lower critical temperature of high carbon steel while hardening is 

a) 960°C 

b) 900°C 

c) 723°C 

d) 560°C 

 

Q6.Which one of the following processes is used for hardening the surface of tool steel? 

a) Carburizing 

b) Cyaniding 

c) Induction hardening 

d) Hardening 

 

 

Q7.The instrument used to measure high temperature in the furnace is 

a) Thermometer 

b) Barometer 

c) Colorimeter 

d) Pyrometer 

 

Q8.H.S.S. is tempered at 

a) 220°C to 230°C 

b) 230°C to 270°C 

c) 280°C to 400°C 

d) 550°C to 600°C 

 

Q9.In nitriding process ammonia gas is produced at 

a) 500°C to 560°C 

b) 575°C to 600°C 

c) 600°C to 650°C 

d) 650°C to 700°C 

 

Q10.The external surface of the part made of mild steel can be hardened by 

a) Tempering 

b) Normalizing 

c) Case hardening 

d) Hardening 

 

Q11.Heat treatment of metals is necessary 

a) To produce certain desired properties 

b) To make good appearance on the component 

c) To increase strength of the metal 

d) To make the metal rust-proof 

 

Q12.A punch is made out of alloyed steel. After hardening it, a crack takes place. What can be the reason to develop this crack? 

a) The punch is heated for too long 

b) The punch is heated too little 

c) The punch is quenched too slowly 

d) The punch is quenched suddenly 

 

Q13.After heating up to required hardening temperature, why must tool steels be quenched? 

a) To induce internal stresses 

b) To build up hardening structure 

c) To fall off the scale 

d) To retain it to its original structure 

 

Q14.’Cyaniding’ and ‘Nitriding’ are two methods of 

a) Hardening 

b) Case Hardening 

c) Tempering 

d) Normalizing 

 

Q15.In a case hardening process, ammonia gas is produced on steel; the process is known as 

a) Cyaniding 

b) Nitriding 

c) Carburizing 

d) Ammonising 


Part 3: List for questions and answers of Heat Treatments                                                             

 

Q1. Answer: b

 

Q2. Answer: c

 

Q3. Answer: a

 

Q4. Answer: c

 

Q5. Answer: c

 

Q6. Answer: c

 

Q7. Answer: d

 

Q8. Answer: d

 

Q9. Answer: a

 

Q10. Answer: c

 

Q11. Answer: a

 

Q12. Answer: b

 

Q13. Answer: b

 

Q14. Answer: b

 

Q15. Answer: b