Engineering Metallurgy - Jun 2015
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) Define the following:
ii) Ledeburite(4 marks) 1 (b) What is 'isomorphous' system? Explain with one example of the same.(4 marks) 1 (c) Draw Fe-Fe3C phase diagram and write the critical temperatures on it.(4 marks) 2 (a) What is stainless steel? For surgical applications which group of stainless steel is used? Explain in detail.(4 marks) 2 (b) Draw a self-explanatory cooling curves for binary eutectic.(2 marks) 2 (c) With a neat diagram explain working of metallurgical microscope.(4 marks) 2 (d) What do you understand by AISI 1090 and Fe-230.(2 marks)
Answer any one question from Q3 and Q4
3 (a) While selecting any material in corrosion, what are the different factor taken into consideration?(6 marks)
3 (b) Write a short note on Nitriding.(4 marks)
3 (c) Explain strain hardening is one of best strengthening mechanism for pure metal.(3 marks)
4 (a) A large size gear needs to be hardened, suggest a suitable heat treatment for the same and justify your answer.(3 marks)
4 (b) What is Crevice corrosion? How it can be reduced?(3 marks)
4 (c) Explain in brief ?Impressed current cathode protection?.(3 marks)
4 (d) Show the following heat treatment on TTT diagram:
(ii) Conventional Hardening.(4 marks)
Answer any one question from Q5 and Q6
5 (a) In which cast iron, carbon is not present in the free form? Explain the treatment ? Which converts cementite into free carbon-graphite. Draw the microstructure after heat treatment.(6 marks)
5 (b) What is mottled cast iron ? Why the formation of this cast iron is avoided?(4 marks)
5 (c) Discuss advantages of gray cast iron over white cast iron.(3 marks)
6 (a) Write True or False and justify your answer:
(i) Chilled cast iron can be used for manufacturing wheels of road rollers.
(ii) Gray cast iron is used for manufacturing bearings.(6 marks) 6 (b) Draw a microstructure of ferritic 'gray cast iron'.(2 marks) 6 (c) What is Ni-Resist cast iron? How does it differ from Nicrosilal?(5 marks)
Answer any one question from Q7 and Q8
7 (a) Give the composition of ?Duralumin?. What are its properties?(4 marks)
7 (b) What is 'Naval Brass'? What are its applications?(4 marks)
7 (c) How 'Invar' differs from 'Elinvar'? Compare their compositions and give one application of each.(4 marks)
8 (a) What properties are required for bearing materials? Give composition of any one non-Ferrous alloy used as bearing.(4 marks)
8 (b) Give typical composition, properties, applications of the following (any two): (i) Cap Brass
(ii) Statuary Bronze
(iii) Muntz metal
(iv) Leaded brass(6 marks) 8 (c) What is Zinc equivalence in brass?(2 marks)