III B.Tech I Semester Regular Examinations,Nov/Dec 2009 HEAT TREATMENT TECHNOLOGY Metallurgy And Material Technology Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) What is solution treatment? Explain its significance in aerospace industry.
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(b) Why do many aluminium alloys respond to age hardening? Give some examples. [8+8] 2. (a) Explain why hardening by quenching is followed by tempering.
(b) Only mechanical properties not physical properties can be altered by heat treatment. Explain.
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(c) Explain the effect of size and mass effect on the hardenability of steels. [6+5+5] 3. (a) What are vacuum furnaces? Explain their role in heat treatment industry. (b) Compare the vacuum furnaces with atmosphere controlled furnaces.
[8+8]
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4. What do you mean by critical temperature? What is its importance? Explain. Name the various critical temperatures that you come across in the Fe-Fe3 C diagram and explain their importance. [16] 5. (a) Which type of steels are best suitable for the following thermomechanical treatments and why? Explain. i. iso-forming ii. ausforming iii. cryoforming
[10+6]
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(b) Expalin the treatments given to steels before nitriding is done.
6. What is SG iron? Explain the different heat treatments given to these cast irons. [16]
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7. Briefly discuss about the following: (a) Paramagnetic steels
(b) Permalloys
[16]
8. (a) Compare and contrast chromium base and tungsten base hot work tool steels. (b) What are shock resisting tool steels? What are the required properties for these steels? With examples, explain a few of them. [8+8] ?????
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Code No: 45042
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III B.Tech I Semester Regular Examinations,Nov/Dec 2009 HEAT TREATMENT TECHNOLOGY Metallurgy And Material Technology Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ?????
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1. (a) Explain advantages offered by salt-bath furnace over other heat treatment furnaces. (b) Write short notes on controlled atmospheres in heat treatment. [8+8]
2. (a) Distinguish fully between steels & cast-irons (b) What is the effect of undissolved carbides on the Ms & Mf temperatures? Discuss [10+6]
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3. What are magnetic grade steels? Explain theircomposition, heat treatment and applications of each type of magnetic grade steels. [16] 4. (a) Describe the factors which control graphitization in cast iron. (b) What is carbon equivalent of gray cast iron? Explain its significance.
[8+8]
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5. (a) Explain the similarities and dissimilarities between cyaniding and carbonitriding process. (b) What are residual stresses? Explain about the presence and nature of residual stresses after carburizing ? How are they eliminated/reduced? Explain. [8+8]
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6. (a) Name a few of the important commercial non-ferrous alloys which are age hardenable. (b) Explain the phase transformations occur during the aging of duralumin alloy. (c) Discuss the effect on corrosion resistance of copper by increasing additions of i. zinc, ii. tin, iii. nickel. [16]
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7. (a) Write the Ms temperature equation. Explain it. Calculate the Ms temperature for carbon steels with 0.2%C, 0.4%Si and 0.7%Mn. (b) Explain the differences between hardness and hardenability. (c) What is the need for sub zero treatment?Discuss. [6+5+5] 8. (a) Water hardening steels are used for upsetting dies for cold heating of bolts, thought they are shallow hardening type. Explain why? (b) Explain the advantages and disadvantages of cold working and hot working. [8+8] ????? 2
Code No: 45042
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III B.Tech I Semester Regular Examinations,Nov/Dec 2009 HEAT TREATMENT TECHNOLOGY Metallurgy And Material Technology Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. Explain the effect of the following elements on the properties of tool steels
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(a) Carbon (b) chromium (c) vanadium (d) tungsten
[16]
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2. Draw Fe-Fe3 C phase diagram and label the phase fields. Discuss in brief the different reactions that take place in this system. [16]
3. What are the various methods of carburizing? Explain any one method in detail. Also give the advantages & limitations of this method over other methods of carburizing. [16]
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4. (a) Explain the difference between cast tough-pitch copper and wrought toughpitch copper? (b) What would be the temper of 0.25” diameter copper wire cold drawn from 0.5” diameter soft wire? (c) What is season cracking? How may it be minimized?
[16]
5. Discuss the applications, advantages and disadvantages of the following:
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(a) Muffle furnace
(b) Vacuum furnace
(c) Continuous furnaces
[16]
6. (a) Explain the classification of Heat resistant steels.
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(b) Explain the heat treatment of heat resistant alloys.
[8+8]
7. (a) Why are graphite flakes in gray iron very often surrounded by ferrite areas? (b) Why should the iron-iron carbide diagram not used to determine the structures in gray iron? (c) Why is malleable iron made only from hypoeutectic white iron?
[16]
8. (a) What is the science of heat treatment? Explain that whether it is true that heat treatment is given to obtain metastable phases.
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Code No: 45042
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(b) Discuss the crystallographic theory of martensitic transformation. Also explain the important properties of martensite. [8+8]
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Code No: 45042
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Set No - 4
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III B.Tech I Semester Regular Examinations,Nov/Dec 2009 HEAT TREATMENT TECHNOLOGY Metallurgy And Material Technology Time: 3 hours Max Marks: 80 Answer any FIVE Questions All Questions carry equal marks ????? 1. (a) Explain the difference in microstructure, composition and properties of white and gray cast iron.
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(b) Differentiate between free and combined carbon.
(c) Discuss the effect of the amount of free carbon on the properties of gray cast iron. [16] 2. (a) Explain about semi ferritic & semi-austenetic alloys.
[12+4]
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(b) Why is it important to know the austenitic grain size of a steel. 3. What are Martensitic valve steels? Explain them with respect to (a) Composition (b) Microstructure
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(c) Heat treatment
[16]
4. (a) Discuss how austenite grain size and carbon content affect hardenability. (b) Distinguish fully between pearlitic transformation and bainitic transformation. [6+10] 5. (a) Explain about
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i. single stage nitriding ii. double stage nitriding
(b) Explain the advantages & disadvantages of nitriding process.
[9+7]
6. (a) Explain the mechanisms of hardening by coherent particles.
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(b) Explain why hardening effect is reduced during overaging. (c) Discuss the heat treatment of Copper-berrylium alloys.
[16]
7. Give a detailed account of classification of heat treatment furnaces. Explain the principle and operation of any two furnaces belonging to two different categories. [16]
8. (a) What do you mean by chromium based hot work tool steels? What are those steels? Give examples. Give the properties and applications of these steels. (b) Explain why we should study i. depth of hardening 5
Code No: 45042
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ii. resistance to decarburization with respect to tool steels.
2. (a) Explain why hardening by quenching is followed by tempering. (b) Only mechanical properties not physical properties can be altered by heat · treatment.
Young's modulus = 35 Ã 1010 Pa and the specific surface energy = 2 J/m2 · (b) Give a brief account on the various stages of creep rate with reference to design.
All Questions carry equal marks · ***** · 1. Explain the microbial production of aminoacids with one example. [16] · 2. What are biofuels? How these are produced ...
1. Explain tree based indexing and hash based indexing techniques. [16] · 2. Explain the .... 1. Explain in detail the structure of B+ tree with an example · [16].
Describe the methods of manipulating DNA for gene cloning purpose. [16] · 5. What are transposons? and describe about the types of bacterial transposons. [16].
what do you understand by Lubrication of Joints? [16] · 5. (a) Explain the three features of viscoelasticity in detail · (b) Explain the working principle of oscillating ...
Perform a Chi-square test at .o5 level whether there is a significance difference ... (b) Derive formulae to find the mean and variance of the Binomial distribution.
and T1 = sink temperature) for a Carnot refrigerator whose COP is 5. Also ... fusible plug, at what temperature should the plug melt to limit the maximum.
[8+8] · 7. (a) List out equipments used in pathology and blood bank departments of a · hospital. (b) Discuss about various blood groups present in humanbeings.
medical equipment. (b) Write a note on responsibilities of BME Department. [8+8] · 8. Discuss the sanitation procedures and laundry services with in a hospital.
Define and derive the equation for the vorticity of a flow. Hence prove that ... out from the leading edge to the trailing edge of a symmetrical airfoil. (b) State and ...
Check whether the following impedance functions are LC, RL or RC? (a) Z(s) = ... amplitude 5 V. Find autocorrelation function and energy spectral density. [8+8].
3. Regeneration is possible in the fixed-bias transistor flip-flop if the base-to-base · voltage gain exceeds unity. Verify that this gain condition is satisfied provided ...
Set No - 2. (b) Write about bus structures. ... (b) Explain time-shared common bus in detail. [8+8] ... (c) Asynchronous serial transmission with one stop bits · [16].
Consider a telegraph source having two symbols, dot and dash. The dot duration · is 0.2s.The dash duration is 3 times the dot duration. the probability of the dots.
(a) Explain how one can test for homogeneous catalyzed reaction using integral · method of Analysis. (b) An ampoule of radioactive Kr- 89 (half life = 76 minutes ) ...
(c) Cell Suspension cultures. ... 6. Explain the process of producing secondary metabolites in culture. ... (a) Discuss the importance of plant tissue culture in India.
3. Effect of radiation on Bone Marrow. (a) Describe the ... (b) Write short notes on artificial respiration. [8+8] ... (b) Write a note on Meta static bone diseases. [8+8].
(a) Explain the terms : Compilers, Linkers, Loaders, Assemblers. (b) Describe the program execution in a system with a neat diagram. [8+8] · 4. (a) Explain Read ...
(c) Explain why XML uses both streaming and tree-based parsing. [4+7+5] · 2. Explain the functionality of javax.servlet package for web servers. Discuss about.
of the offset point D on the coupler AB, and the angular velocities of links OA and ... lengths AB : OO1 : OA :: 1 : 2 : 2.5 for the point P to move in an approximate.
