Casting Problems on “Air Requirements And Metallurgical Control For Cupola”.
1. What mass of oxygen is required for burning 1 kg of iron?
a) 1.12 kg
b) 2.67 kg
c) 2.35 kg
d) 1.92 kg
Answer: b
Clarification: Oxygen is the primary requirement for the process of burning to take place. For the burning of a metal such as iron, a high amount of oxygen will be needed. The mass of oxygen required for burning iron is 2.67 kg.
2. What volume of oxygen is required for burning 1 kg of carbon?
a) 7.67 m3
b) 9.89 m3
c) 8.98 m3
d) 6.67 m3
Answer: c
Clarification: None.
3. Carbon pickup does not depend on which of the following factors?
a) Size of coke
b) Height of coke bed
c) Cupola temperature
d) Cupola diameter
Answer: d
Clarification: Magnitude of carbon pickup depends on various factors such as the presence of original carbon content, size of the coke, height of the coke bed, temperature of cupola and a few more, but it does not depend on the diameter of the cupola.
4. In the iron-iron carbide diagram, what is the carbon percentage by weight at eutectic point?
a) 0.8%
b) 3%
c) 4.3%
d) 6.67%
Answer: c
Clarification: In the iron iron-carbide equilibrium diagram, the eutectic point is achieved at a temperature of 1147°C. At this point, the percentage amount of carbon is 4.3% by weight.
5. In the iron-iron carbide diagram, what is the carbon percentage by weight at eutectoid point?
a) 0.8%
b) 0.18%
c) 4.3%
d) 6.67%
Answer: a
Clarification: None.
6. At what temperature, in the Fe-Fe3C diagram, does the peritectic region occur?
a) 1400°C
b) 1423°C
c) 1492°C
d) 1539°C
Answer: c
Clarification: In the iron – iron carbide diagram, or the Fe-Fe3C equilibrium diagram, the peritectic transformation occurs at a very high temperature. The temperature point of peritectic reaction takes place is 1492°C.
7. In the iron-iron carbide diagram, what is the carbon percentage by weight in the peritectic region?
a) 0.8%
b) 0.18%
c) 4.3%
d) 6.67%
Answer: b
Clarification: None.
8. Carbon picks up can be of what order?
a) 10%
b) 15%
c) 20%
d) 25%
Answer: b
Clarification: In carbon pick up, there is an increase in the carbon content because of absorption from coke, but there is a reduction also, because of oxidation. The order of carbon pick up can be of 15%.
9. During metallurgical control, what is the amount of manganese that is lost?
a) 5%
b) 10%
c) 15%
d) 20%
Answer: c
Clarification: During metallurgical control, the amount of manganese lost is about 15%. This loss takes place because of the presence of oxygen, that is, an oxidation reaction takes place.
10. Sulphur is present in coke.
a) True
b) False
Answer: a
Clarification: Sulphur is present in coke, but in a very small composition, approximately 0.5% to 1%, which is picked up by cast iron.