Engineering Metallurgy - May 2014

Mechanical Engg (Semester 4)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks.

Answer any one question from Q1 and Q2

1 (a) What are the advantages of alloy steels over plain carbon steel.(4 marks) 1 (b) Draw an equilibrium diagram for Ag-Cu system which are partially soluble in the solid state.The data is as follows:- Melting temp. of Ag=961°C, Melting temp. of Cu=1083°C, Eutectic composition-28.1% Cu, Eutectic temp. =7807deg;C, Solubility of Cu in Ag=8.8% Cu at 780°C, Solubility of Ag in Cu=92.1% Cu. The solubility in both decreases to 2% at room temperature. Discuss slow cooling of alloy with 6% Cu from liquids temperature.(6 marks) 1 (c) Explain the weld decay in stainless steels.(3 marks) 2 (a) Draw iron carbon equilibrium diagram.(4 marks) 2 (b) Draw the microstructures of: 1) AISI 1020 steel.(2 marks) 2 (c) State the Hume Rothery's rules of solid solubility.(4 marks) 2 (d) What is coring? Which alloys show cored structures?(3 marks)

Answer any one question from Q3 and Q4

3 (a) Explain secondary hardening.(2 marks) 3 (b) What are the advantages and disadvantages of Induction hardening over Flame hardening.(4 marks) 3 (c) Explain how corrosion can be prevented by taking care in proper design.(3 marks) 3 (d) Explain what is anodic protection.(3 marks) 4 (a) Draw self explanatory diagram for any one of the below:
1) Ausforming
2) Martempering(2 marks) 4 (b) Write short notes on ( Any one )
: 1) Carbonitriding
2) nitriding(4 marks) 4 (c) Explain min 4 types of corrosion .(4 marks) 4 (d) What is cathodic inhibitors.(2 marks)

Answer any one question from Q5 and Q6

5 (a) What is chilled cast Iron, how it is produced? Give its applications?(4 marks) 5 (b) Draw microstructure: 1) Ferritic Spheroidal gray cast iron, 2) 4.3 eutectic cast Iron(4 marks) 5 (c) Explain the cooling of 3.5 % carbon cast Iron from its melting temperature till room temperature.(4 marks) 6 (a) What is Equivalent carbon in cast Iron. Explain role of individual element present in Equivalent carbon in cast iron.(4 marks) 6 (b) Compare S.G. iron and Malleable iron with respect to microstructure, production, composition and one application each.(4 marks) 6 (c) What are the advantages of cast iron over steels?(4 marks)

Answer any one question from Q7 and Q8

7 (a) Give typical composition, property and application for the following ( any four):
1) LM14
2) Invar
3) statuary bronze
4) cartridge brass
5) Gun metal(12 marks) 7 (b) Ni is used in measuring equipment justify its property for this application.(1 marks) 8 (a) Explain classification of Cu base alloys based on the percentage of Cu and Zn? Explain role of Zn in brasses.(4 marks) 8 (b) Write short note on 1) Dezincification 2) coring in Sn bronzes.(4 marks) 8 (c) What are the requirements of bearing materials? explain with suitable example.(5 marks)