09A51804 Heat Treatment Technology B.Tech Question Paper : sphoorthyengg.com

Name of the College : Sphoorthy Engineering College
University : JNTUH
Department : Metallurgy And Material Technology
Subject Code/Name : 09A51804/HEAT TREATMENT TECHNOLOGY
Year : December 2011
Degree : B.Tech
Year/Sem : III/I
Website : sphoorthyengg.com
Document Type : Model Question Paper

Download Model/Sample Question Paper : https://www.pdfquestion.in/uploads/sphoorthyengg.com/4813-09A51804%20-HEAT%20TREATMENT%20TECHNOLOGY.pdf

Heat Treatment Technology Question Paper :

B. Tech III Year I Semester Examinations, December-2011
(METALLURGY AND MATERIAL TECHNLOGY)
Time: 3 hours

Related : Sphoorthy Engineering College 09A51805 Iron Production B.Tech Question Paper : www.pdfquestion.in/4812.html

Max. Marks: 75
Answer any five questions :
All questions carry equal marks :
1.a) Draw Fe-Fe3C phase diagram and indicate the points, lines and areas.
b) What is an invariant reaction? Explain three invariant reactions in Fe-Fe3C phase diagram with complete information. [7+8]

2. Discuss the reaction that take place between the following in a furnace under controlled atmospheres and explain their role. (a) Metal and oxygen (b) Metal and carbon (c) Different gases. [15]

3.a) What are TTT curves? Explain the construction of TTT curves for 0.8% C steel.
b) Explain the phase transformations in 0.8% steel cooled from austenite to room temperature under different cooling rates. [7+8]

4.a) Which factors affect the properties of a gray cast iron? How are they controlled to obtain optimum properties?
b) Find the weight percentages of ferrite, graphite and cementite in a pearlitic-ferritic gray cast iron containing 4.0% total carbon and 0.4% combined carbon. [7+8]

5.a) What is quench severity? List the industrial coolants mentioning their quench severity in the increasing order.
b) What is tempering? Explain its importance in the heat treatment of metals and alloys.
c) Discuss the mechanism of heat removal during quenching. [5+5+5]

6. Write short notes on the following:
a. Austempering b. Martempering c. Patenting. [5+5+5]
7. Distinguish between the following surface hardening processes:
a. Nitriding b. Cyaninding c. Carbonitriding. [5+5+5]

8. Classify the type of cast irons with respect to the following: Composition, Microstructure, Mechanical properties and Applications. [15]

R09Code No: 09A51804
SET-2
1.a) Hypo eutectoid steels are completely austenitized while annealing where as hyper eutectoid steels are not. Why? Explain with proper reasons.
b) Maximum solubility of carbon in g-iron is 2.0% while in a-iron is only 0.025. Why?
c) What ASTM stands for? How ASTM grain size is defined? [5+5+5]

2. Write short notes on the following:
a) Conveyor furnace b) Pit furnace c) Muffle furnace [5+5+5]
3. Distinguish between the following:
a. Pearlite, bainite and martensite b. TTT curves and IT curves. [8+7]

4.a) Explain the difference in microstructure, composition and properties of white and gray cast iron.
b) Differentiate between free and combined carbon. c. Discuss the effect of the amount of free carbon on the properties of gray cast iron. [7+8]

5.a) What is annealing? Explain different types of annealing treatments.
b) Explain the effect of size and mass of the material during quenching. [7+8]
6. Write short notes on the following:
a. Spheroidizing b. Ausforming c. Cryoforming [5+5+5]

7.a) Compare and contrast between induction hardening and flame hardening.
b) What is nitriding? Explain the conditions for nitriding of steels. [7+8]

8.a) Distinguish between alloy steels and plain carbon steels.
b) Explain the necessity of adding alloying elements to the plain carbon steels.[7+8]

B. Tech III Year I Semester Examinations, December-2011 :
Heat Treatment Technology :
1.a) What is the grain size when 0.2% steel is observed at 200X and grain size number 4?
b) Why fine grain steel exhibit yield strength near to ultimate tensile strength compared to coarse grain steel? C. Define the terms: Ac1, Ar1, A1,3, Acm and A3 temperatures with respect to Fe-Fe3C diagram. [7+8]

2. Write short notes on the following with neat sketches :
a) Batch furnaces b) Continuous furnaces [7+8]
3.a) Why mild steel cannot be hardened? Explain.
b) What is bainite? Distinguish between bainite and martensite.
c) Distinguish between upper bainite and lower bainite. [5+5+5]

4.a) Distinguish between first stage of graphitization and second stage of graphitization?
b) Explain the effect of malleabilizing cycle on microstructure. [7+8]

5.a) What is hardening? Explain the role of alloying elements on hardening of steels.
b) Compare and contrast between full annealing and normalizing. [7+8]
6. Write short notes on the following:
a. Sub-zero treatment b. Thermo-mechanical treatment [7+8]

7. Explain the following surface hardening treatments with respect to process, temperature and applications:
a. Pack carburizing b. Cyaniding c. Induction hardening. [5+5+5]
8.a) What are maraging steels? Why they are named so?
b) Explain the heat treatment of maraging steels. [7+8]