Metallurgy Interview Questions and Answers

• What is the composition of grey cast iron grade 20?

Carbon: 3.10-3.25%  Silicon : 1.75–1.95%  Manganese : 0.50-0.75% Sulphur : 0.05-0.07%  Phosporous : 0.04-0.07%

• What is the composition of cast iron grade 35? | Metallurgy Interview Questions and Answers

Carbon =2.90-3.10% Manganese = 0.60-1.00% Silicon = 1.50-1.90% Sulphur =0.10%

Phosphorus=0.15%  Chromium=0.30%        Molybdenum = 0.30 %  Cupper=0.25%

• What are the superalloys? | Metallurgy Interview Questions And Answers

A superalloy is an alloy that exhibits excellent mechanical strength and creep resistance at high temperatures, having a good surface finish.

• Why are the Superalloys used for land-based turbines?

Superalloys are the topmost alloys used for their excellent strength, corrosion resistance, as well as oxidation resistance. No other alloy can compete with this grade.

• Only rocket engines can be propelled to space because

  1. They can generate very high thrust.
  2. They have high propulsion efficiency.
  3. These engines can work on several fuels
  4. They are not air-breathing engines.

Answer:

1. They are not air-breathing engines.

• What kinds of NDT methods are available? | Metallurgy Interview Questions and Answers

1. Visual Inspection
2. Microscopy inspection
3. Radiography Test
4. Dye Penetrate technique
5. Ultrasonic testing
6. Magnetic Particle Inspection
7. Eddy Current technology
8. Acoustic Emission
9. Thermograph
10. Replica Metallographic

• What is Stress Corrosion cracking? | Metallurgy Interview Questions And Answers

Stress corrosion cracking (SCC) is a process involving the initiation of cracks and their propagation, possibly up to the complete failure of a component, due to the combined action of tensile mechanical loading and a corrosive medium.

• What is meant by D2 material used for die tooling?

D2-High Carbon Cold Work Tool Steel

D2 is a high carbon, high chromium, Molybdenum, Vanadium, and air hardening alloy tool steel that offers good wear resistance, high surface hardness, through hardening properties, dimensional stability, and high resistance to tempering effects. D2 tool steel is also suitable for vacuum hardening.

Typical composition

C.-1.50%

Si.-0.30%

Cr.-12.00%

Mo. -0.80%

V.-0.90%

• If in a petrol engine, by mistake, diesel fuel is supplied.

  1. The engine will not run.
  2. The engine will run at a lower RPM.
  3. The engine will run at reduced efficiency.
  4. The engine will give dense smoke and will consume more fuel as well as lubrication oil.

Answer:

The engine will not run.

Reason:

Diesel will not vaporize in the carburetor to form an adequate air-fuel ratio, hence the engine will not run

• What is Vacuum Induction Melting? | Metallurgy Interview Questions And Answers

As the name suggests, the process involves the melting of metal under vacuum conditions. Electromagnetic induction is used as the energy source for melting the metal.

Induction melting works by inducing electrical eddy currents in the metal. The source is the induction coil which carries an alternating current. The eddy currents heat and eventually melt the charge.