Corrosion Engineering MCQ

Test your knowledge with important Corrosion Engineering MCQ and their applications. These MCQs are beneficial for competitive exams too. Explore 30 + more Corrosion Engineering MCQs at Bissoy

• Which of the following is/are the limitations of high-temperature non-metallic materials?
  ক

  Lack of ductility

  খ

  Less resistance to thermal shock

  গ

  Weldability, less resistance to thermal shock, lack of ductility and formability

  ঘ

  Weldability and formability
• Which of the following is/are the high melting point metals?
  ক

  Molybdenum

  খ

  Tungsten

  গ

  Columbium

  ঘ

  Molybdenum, tungsten, columbium, and tantalum
• Which of the following nickel-based alloys is/are superalloys?
  ক

  Hastelloy C-276

  খ

  Inconel 718

  গ

  Hastelloy C-276, Inconel 718 and Hastelloy HX

  ঘ

  Hastelloy HX
• Which of the following metallurgical changes that affect the structural stability of metals at high temperatures?
  ক

  Grain growth, phase changes, precipitation dissolution and precipitation over aging

  খ

  Grain growth and phase changes

  গ

  Precipitation dissolution and precipitation over aging

  ঘ

  Phase changes, precipitation dissolution and precipitation over aging
• Which of the following strengthening mechanisms is/are used to attain high-temperature strength?
  ক

  Solid-solution strengthening

  খ

  Precipitation hardening

  গ

  Dispersion hardening

  ঘ

  Solid-solution strengthening, precipitation hardening or dispersion hardening
• Which of the following is/are the adequate high-temperature mechanical properties to avoid fracture?
  ক

  Low creep rate and high stress-rupture strength

  খ

  High stress-rupture strength, low creep rate, and high fracture toughness

  গ

  High stress-rupture strength and high fracture toughness

  ঘ

  Low creep rate and high fracture toughness
• Which of the following is/are true regarding stress rupture?
  ক

  The stress required to cause a rupture in a predetermined time at a constant temperature

  খ

  It is important in short-term high-temperature applications

  গ

  Stress rupture is an important mechanical property for gas turbine or rocket engines

  ঘ

  The stress required to cause a rupture in short-term high-temperature applications at a predetermined time is known as stress rupture and it is an important mechanical property for gas turbines and rocket engines
• Which of the following is/are correct regarding creep?
  ক

  It is the continuous plastic elongation of metal under constant load

  খ

  It is the high-temperature mechanical effect of a metal

  গ

  It is the continuous plastic elongation of metal under constant load at high temperature and it can be minimized by the fraction of grain boundaries

  ঘ

  It can be minimized by reducing the fraction of grain boundaries
• Which of the following mechanical properties is/are important in structural applications of metals?
  ক

  Tensile strength

  খ

  Yield strength

  গ

  Ductility and Elasticity

  ঘ

  Tensile strength, Yield strength, Ductility, and Fracture toughness
• Dilute alloying elements of base metals exhibiting a relatively high solubility and diffusivity for atomic oxygen are subject to internal corrosion.
  ক

  True

  খ

  False
• Which of the following is/are true regarding internal corrosion?
  ক

  Corrosion products precipitate in the metal matrix

  খ

  Corrosion products precipitate in the metal matrix and metals such as Fe, Ni, and Co are highly prone to internal corrosion

  গ

  Corrosion occurs on external surfaces of metals

  ঘ

  It is due to the stable corrosion products of base metals
• Which of the following metals results in the formation of volatile oxides?
  ক

  Molybdenum

  খ

  Tungsten

  গ

  Osmium, tungsten, molybdenum, and Vanadium

  ঘ

  Vanadium
• Which of the following metals results in the ignition in extreme cases?
  ক

  Sodium

  খ

  Magnesium

  গ

  Niobium

  ঘ

  Sodium, magnesium, and niobium
• Metals that follow linear oxidation kinetics at low temperatures tend to oxidize catastrophicallyat high temperatures.
  ক

  True

  খ

  False
• Which of the following metals follows logarithmic oxidation law?
  ক

  Aluminum

  খ

  Copper

  গ

  Iron

  ঘ

  Aluminum, copper, and iron
• Which of the following is/are true regarding parabolic oxidation rate law?
  ক

  It was proposed by C. Wagner

  খ

  It states that square of weight loss is directly proportional to the time of exposure

  গ

  It was proposed by C. Wagner which states that square of weight loss is directly proportional to the time of exposure and it resembles non-steady-state diffusion-controlled reactions

  ঘ

  It resembles non-steady-state diffusion-controlled reactions
• Which of the following metal doesn’t follow linear oxidation law?
  ক

  Sodium

  খ

  Aluminum

  গ

  Niobium

  ঘ

  Potassium
• Which of the following is/are correct regarding linear oxidation law?
  ক

  Weight gain per unit area of the metal is directly proportional to the exposure time

  খ

  It is a characteristic of porous or cracked scale

  গ

  Sodium is an example that follows linear oxidation law

  ঘ

  Weight gain per unit area of metal is directly proportional to exposure time, it is characteristic of porous or cracked scale and sodium follows linear oxidation law
• What are the types of oxidation rate laws?
  ক

  Linear and parabolic law

  খ

  Cubic and logarithmic law

  গ

  Linear, parabolic and cubic law

  ঘ

  Linear, parabolic, cubic and logarithmic law
• Diffusion-controlled oxidation can be minimized by decreasing the concentration of ionic defects in the scale.
  ক

  False

  খ

  True
• Which of the following is/are correct regarding the measurement of the rate of oxidation?
  ক

  Weight loss per unit area of metal is the measure of the rate of oxidation

  খ

  Either weight loss or weight gain per unit area of metal is the measure of the rate of oxidation

  গ

  Weight gain per unit area of metal is the measure of the rate of oxidation

  ঘ

  Neither weight loss nor weight gain per unit area of metals is the measure of the rate of oxidation
• In general, all oxides are nonstoichiometric in nature their composition varies from an ideal molecular formula.
  ক

  True

  খ

  False
• Which of the following is/are the p-type semiconducting oxides?
  ক

  FeO and MnO

  খ

  FeO, MnO, Cu2O, and CoO

  গ

  Al2O3, MnO, and CoO

  ঘ

  CdO2, Cu2O, and Mno
• Which of the following is/are the n-type semiconducting oxides?
  ক

  CdO2

  খ

  TiO2

  গ

  Al2O3, CdO2, and TiO2

  ঘ

  CoO
• Which of the following metal(s) produces metal oxide at a metal-scale interface?
  ক

  Titanium

  খ

  Niobium

  গ

  Zirconium

  ঘ

  Titanium, Niobium, and Zirconium
• The relative thickness of each phase of a metallic oxide is determined by the rate of ionic diffusion through that phase.
  ক

  True

  খ

  False
• Which of the following order is correct regarding the oxides of iron starting from metallic iron to gaseous oxygen interface?
  ক

  FeO, Fe2O3, and Fe3O4

  খ

  Fe2O3, Fe3O4 and FeO

  গ

  Fe3O4, Fe2O3, and FeO

  ঘ

  FeO, Fe3O4, and Fe2O3
• The diffusion of either cation or oxygen ions usually controls the reaction rate of high-temperature metallic oxidation.
  ক

  True

  খ

  False
• Which of the following is/are the interface at which new metallic oxides (MO) are produced?
  ক

  Metal-scale interface

  খ

  Scale-gas interface

  গ

  Metal-scale interface or scale-gas interface

  ঘ

  Neither metal-scale interface nor scale-gas interface
• What is the value of the Pilling and Bed worth ratio of tungsten?
  ক

  1.21

  খ

  3.40

  গ

  2.60

  ঘ

  0.45