Download - Heat Treatment Technology (1)
Ex/MET/T/415/25/2009
BACHELOR OF METALLURGICAL ENG. FINAL EXAMINATION, 2009
(4th Year, 1st Semester)
HEAT TREATMENT TECHNOLOGY
Time : Three hours Full Marks : 100
Answer any five questions.
All questions carry equal marks.
1. Discuss the following : 4×5=20
a) Different type of resistors used in electrical heat
treatment furnace.
b) Exo gas and endo gas atmosphere.
c) Salt bath f/c.
d) Batch f/c and continuous f/c.
2. Discuss about the major defects (any four) : 4×5=20
a) Soft spots.
b) Oxidation and decarburisation.
c) Overheating and burning.
d) Quench Crack.
e) Distortion and warping.
[ TURN OVER ]
( 2 ) ( 3 )
3. a) Define Hardenability.
b) Discuss the factors which are responsible for influencing
hardenability.
c) Compare the advantage and disadvantage of Grossman
Critical diameter test with Jominy End Quench test.
4+12+4
4. Give typical composition, heat treatment cycle and
properties evolved in the following grades of steel :
(any two) 2×10
(a) Maraging steel, (b) High speed steel (c) Martensitic
stainless steel.
5. Write short notes on the following thermomechanical
treatment :
(a) Ausforming (b) Isoforming (c) Cryoforming
(d) HTMT and LTMT. 4×5
6. Discuss the heat treatment schedule of the following :
(any two) 2×10
a) Heat Treatment of wrought AL - Alloys.
b) Heat Treatment of Ti Alloys.
c) Heat Treatment of Mg Alloys.
7. a) A small gear made of 0.15% C is to be carburised to a
depth of 1 mm and heat treated. Give the complete heat
treatment schedule. How can you control the surface
carbon content in the carburised portion ? 6+4
b) Nitriding can be performed at a lower temperature than
carburising — why ?
What is white layer in nitriding ?
How is it avoided ? 3+2+1
c) A steel shaft (50 mm dia) is to be surface hardened and
tempered to get a surface hardness of RC 45. Suggest
suitable steel and heat treatment method. 2+2
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