Heat Treatment Technology Mid - II, November - 2014

1.Characteristic feature of had field manganese steel is
  • Impact hardness
  • Air hardening
  • Strain aging
  • Quench hardening
Answer: A
2.Hadfield silicon steels are extensively used in
  • Rooter shaft
  • Stator body
  • Transformer core
  • Temperature measurement
Answer: C
3.The main purpose of Chromium in stainless steels is
  • To improve mechanical properties
  • To improve hardenability
  • To improve corrosion resistance d) To improve ductility
Answer: C
4.Microstructure of malleable cast Iron is
  • Temper carbon nodules in pearlite matrix
  • Graphite nodules in pearlite matrix
  • Massive iron carbides in pearlite matrix
  • Graphite cakes in pearlite matrix
Answer: A
5.Major alloying elements in precipitation hardenable stainless steels are
  • Co, Mo
  • Cb, Cu
  • Cr, Ni
  • Al, Ti
Answer: C
6.The gas not used in gas carburizing is
  • Carbon dioxide
  • Carbon monoxide
  • Carrier gas
  • Methane
Answer: A
7.The purpose of alloying of steels do not include
  • Increase hardenability
  • Decrease wear resistance
  • Increase corrosion resistance
  • Improve mechanical properties
Answer: B
8.Find the incorrect statement
  • Silicon and vanadium are ferrite stabilizers
  • Carbide forming elements are very powerful deep-hardening elements
  • Nickel and manganese are austenite stabilizers
  • Chromium and vanadium decrease the wear resistance
Answer: D
9.The gray cast iron exhibit maximum strength and wear resistance when it possess matrix
  • Ferrite
  • Pearlite
  • Austenite
  • Cementite
Answer: B
10. ----------------- produces structures and properties very much similar to tempered martensites without involving in martensitic transformation
  • Martempering
  • Normalising
  • Patenting
  • Austempering
Answer: D
11.In annealing of Ti alloys ______________ atmosphere is used.
Answer: Vacuum
12.What is the percentage of carbon in medium carbon steels _________________.
Answer: 0.3 to 0.6
13.Percentage of Silicon in Hadfield silicon steels is ____________.
Answer: 4.5
14.Nodular cast Iron is also called __________________________.
Answer: Spheroidal graphite or Ductile Iron
15.Carbon Equivalent is given by __________________________.
Answer: % C +1/3(%Si+%P)
16.The effect of the alloying elements on the hardness of tempered steel is very little because _______________________.
Answer: They dissolve in ferrite
17.Addition of chromium (0.15-1%) to cast iron decreases ___________________.
Answer: Machinability
18.Zirconium (0.1-0.3%) addition to cast iron reduces _______________________.
Answer: Its hardness
19.Austenitized steel is cooled with a rate exceeding the critical cooling rate of that steel to a temperature between the nose and Ms, forged or rolled at this temperature and cooled to room temperature in oil. This process is called ___________________.
Answer: Ausforming
20._____________ consists of cooling the austenitized steel with a rate exceeding critical cooling rate in a molten bath held in the bainite region, holding at this temperature for a sufficient period for the completion of bainitic transformation and cooling to room temperature at any desired rate.
Answer: Austempering