Casting, Forming and Welding Multiple Choice Questions & Answers (MCQs) on “Classification of Defects & Factors Affecting Salvage of Castings”.
1. Inspection of quality in a unit casting is much easier and beneficial, rather than inspecting it by separating the entire casting.
a) True
b) False
Answer: b
Clarification: It is very important to mention the correct qualifications of criterion usage of quality improvement tools. Separation of casting in parts takes place to investigate all the spheres of formation easily and usage of products to make an accurate inspection, but it may increase the time for inspection of castings.
2. The castings of minor defects can be salvaged economically without any high expense.
a) True
b) False
Answer: a
Clarification: The minor defects, which can totally allow the castings to be economically salvaged and leave a reasonable margin for the profit in a production of castings, but the major defects in the castings cannot be salvaged and results into the rejection of the casting and total loss of the production.
3. Which of the following is not part of an integrated management system in the production of casting?
a) Quality of production
b) Protection of environment
c) Casting yield
d) Safety in working conditions
Answer: c
Clarification: The quality of production, protection of environment, safety and protection of humans and machines in working conditions are integral part of management system. Integrated management system is the system which integrates management systems into one continuous system. Casting yield is another concept which does not considered in integrated management system.
4. The defects in the castings are majorly caused by the surrounding environmental conditions.
a) True
b) False
Answer: b
Clarification: The surrounding has negligible affects on the castings. The defects are majorly caused by unsuitable raw materials used in moulding, using improper tools, equipment, patterns. And sometimes faulty organization and lack of training for the workers can also lead to the inducement of defects in the castings.
5. The decision for rejection or replacement of casting is majorly considered with respect to the functioning of casting instead of defects in the castings.
a) True
b) False
Answer: a
Clarification: The decision for rejection or replacement of casting should be based upon not only the presence of defects in the casting itself but also on the significance in relation to the functioning or working of the casting product. This makes salvaging of casting products more easy and efficient.
6. Varieties or non-standardizing in the production of castings gives more safety and protection from the defects.
a) True
b) False
Answer: b
Clarification: In the production of casting components, close control and standardization of all aspects of technique give the best safety and protection against the inducement of defects in the castings. And it becomes easier to understand the laws and designs related to production by implementing standardization.
7. Defects like sand inclusion in the metal casting can lead to rejection of the whole casting.
a) True
b) False
Answer: a
Clarification: Sand inclusion is one of the most frequent causes for rejection of casting. It is very difficult to diagnose, as this type of defect normally occurs at varying positions in the casting which is caused by eroding of sand by a metal stream and then float to the surface of the casting. So it is not easy to attribute to a local cause.
8. In the case of steel castings, the salvaging operations are costlier than the conversion operations.
a) True
b) False
Answer: b
Clarification: In case of steel castings, the salvaging operation is preferred as a cost of salvaging is much cheaper than the total conversion, while in case of grey cast iron castings, sometimes the salvaging operations are costlier than the conversion process. Salvaging is only preferred when it is economical for the castings.
9. In proper design and working of the casting system, the salvaging operation can be avoided.
a) True
b) False
Answer: a
Clarification: Salvaging is one of the most costs affecting constituent and an avoidable operation. Salvaging can be avoided if the casting process takes place in the correct manner and according to the design considered. The success of the production of castings is indirectly proportional to the extent of salvaging carried out.
10. Electrodes are basically used in the process of salvaging which are more or less similar to the base composition of the casting.
a) True
b) False
Answer: a
Clarification: Despite the continuous technological growth, a certain percentage of castings always possesses imperfections that further cause defects in the casting product. The salvaging is always carried out using electrodes, whose composition is more or less similar to the base composition of the casting.
11. Which of the following is not a gas defect?
a) Blow holes
b) Run out
c) Pinhole porosity
d) Air inclusions
Answer: b
Clarification: Run out is not a gas defect, instead it is a moulding material defect.
12. Which of the following is a metallurgical defect?
a) Hotspots
b) Shrinkage cavities
c) Slag inclusions
d) Metal penetration
Answer: a
Clarification: Hot spots are a type of metallurgical defect. Occurs due to the chilling of the casting.
13. Dropping of loose moulding sand or lumps is responsible for which of the following defect?
a) Misruns
b) Cuts
c) Drop
d) Fusion
Answer: c
Clarification: Drop defect is caused when anything including loose sand and lumps drops from the cope into the drag portion of the casting.
14. Shrinkage cavities are compensated by ___________
a) Providing proper chill techniques to the casting
b) Providing proper feeding of liquid to the casting
c) Using specific risers
d) Using proper ramming during solidification
Answer: b
Clarification: Shrinkage cavities are formed due to volume decreasing phenomena while solidification of liquids. Proper liquid metal feed is given to reduce the effect of shrinkage.
15. Proper ramming is used to eliminate which of the following defects?
a) Swell
b) Run out
c) Pinhole porosity
d) Cuts and washes
Answer: a
Clarification: Heavy metallostatic forces cause the mould wall to move back and result in an increment in dimensions if the casting. Good ramming techniques are used to eliminate this defect.