VTU Question Paper
Eighth Semester B.E. Degree Examination, June/July 2015
Foundry Technology
Time: 3 hrs. Max. Marks: 100
Note: Answer FIVE full questions, selecting at least TWO questions from each part. '"
PART-A
1. a. Explain in brief, i) Use of solid degassers ii) Vacuum degassing to obtain good casting.(10 Marks)
b. Explain shrinkage of liquid metals. (10 Marks)
2. a. Explain the following: i) Casting predesign consideration ii) Design for directional solidification.
b. Explain: i) Design for minimum casting stresses. ii) Design for low pattern cost. (10 Marks)
3 a. Write a note on refinement and modification of cast structure.
b. Explain Chvorinovs rule and its influence of mold characteristic and cast metal.
4 a. What are the requirements of a riser? Write a short notes on riser shapes and riser size.
5 b. With a neat ketch, explain gating system with modem nomenclature.
PART-B
a. With a neat sketch, explain vacuum moulding (V -process). (10 Marks)
b. In a foundry it was required to obtain a cast metal with the following composition:
Carbon 3.2 to 3.6 % Silicon 2.3 to 2.6%
Manganese 0.6 to 0.8 % Sulphur upto 0.8%
Phosphorous 0.4 to 0.6%
If the following raw ~aterials are available, estimate the best charge proportions.
C Si Mn S P
3.5 3.00 1.00 0.02 0.4
3.2 1.5 0.5 0.01 0.8
3.5 2.5 0.8 0.02 0.5
3.5 1.8 0.6 0.08 0.5
3.2 1.2 0.6 0.10 0.4
6
Pig iron 1
Pig iron 2
Pig iron 3
Scrap I
Scrap 2
Ferrosilicon containing 50% silicon.
If the charge consist of, i) Pig iron] = 25 % ii) Pig iron 2 = ] 5% iii) Pig iron 3 = 10%
iv) Scrap] = 20% v) Scrap 2 = 30%
The loss or gains of various elements is as follows:
C = no gain/loss Mn = loss 15% Si = loss 10%
Phosphorous = no loss / gain
a. i) Discuss the effect of any 5 alloying elements on the properties of steel.
ii) Briefly explain the production of spheroidal graphite cast iron. (10 Marks)
b. What are the different types of melting furnaces employed in ferrous foundries? With a neat sketch explain induction furnace. (10 Marks)
a. Explain melting procedure and casting characteristics of Magnesium based alloys. (10 Marks)
b. Explain melting procedure and casting characteristics of copper based alloys. (10 Marks)
8 a. What is mechanization? What are the advantages of mechanization? Draw the layout of mechanized foundry. (10 Marks)
b. What is the purpose of sand reclamation? Write the flow chart of the process and methods of
reclamation of sands. (10 Marks)
Eighth Semester B.E. Degree Examination, June/July 2015
Foundry Technology
Time: 3 hrs. Max. Marks: 100
Note: Answer FIVE full questions, selecting at least TWO questions from each part. '"
PART-A
1. a. Explain in brief, i) Use of solid degassers ii) Vacuum degassing to obtain good casting.(10 Marks)
b. Explain shrinkage of liquid metals. (10 Marks)
2. a. Explain the following: i) Casting predesign consideration ii) Design for directional solidification.
b. Explain: i) Design for minimum casting stresses. ii) Design for low pattern cost. (10 Marks)
3 a. Write a note on refinement and modification of cast structure.
b. Explain Chvorinovs rule and its influence of mold characteristic and cast metal.
4 a. What are the requirements of a riser? Write a short notes on riser shapes and riser size.
5 b. With a neat ketch, explain gating system with modem nomenclature.
PART-B
a. With a neat sketch, explain vacuum moulding (V -process). (10 Marks)
b. In a foundry it was required to obtain a cast metal with the following composition:
Carbon 3.2 to 3.6 % Silicon 2.3 to 2.6%
Manganese 0.6 to 0.8 % Sulphur upto 0.8%
Phosphorous 0.4 to 0.6%
If the following raw ~aterials are available, estimate the best charge proportions.
C Si Mn S P
3.5 3.00 1.00 0.02 0.4
3.2 1.5 0.5 0.01 0.8
3.5 2.5 0.8 0.02 0.5
3.5 1.8 0.6 0.08 0.5
3.2 1.2 0.6 0.10 0.4
6
Pig iron 1
Pig iron 2
Pig iron 3
Scrap I
Scrap 2
Ferrosilicon containing 50% silicon.
If the charge consist of, i) Pig iron] = 25 % ii) Pig iron 2 = ] 5% iii) Pig iron 3 = 10%
iv) Scrap] = 20% v) Scrap 2 = 30%
The loss or gains of various elements is as follows:
C = no gain/loss Mn = loss 15% Si = loss 10%
Phosphorous = no loss / gain
a. i) Discuss the effect of any 5 alloying elements on the properties of steel.
ii) Briefly explain the production of spheroidal graphite cast iron. (10 Marks)
b. What are the different types of melting furnaces employed in ferrous foundries? With a neat sketch explain induction furnace. (10 Marks)
a. Explain melting procedure and casting characteristics of Magnesium based alloys. (10 Marks)
b. Explain melting procedure and casting characteristics of copper based alloys. (10 Marks)
8 a. What is mechanization? What are the advantages of mechanization? Draw the layout of mechanized foundry. (10 Marks)
b. What is the purpose of sand reclamation? Write the flow chart of the process and methods of
reclamation of sands. (10 Marks)
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