This set of Aerospace Materials and Processes Multiple Choice Questions & Answers (MCQs) focuses on “Properties of Steel and its Alloys”.
1. The steel being used in the construction of aircraft must be ___________ to fabricate.
Explanation: There are several requirements that have to be checked for materials that have to be used in aircraft construction, like mechanical properties. One of the properties is the ease of fabrication of the material.
2. The amount of carbon present in low carbon steels is ___________
a) 5% to 7%
b) 0.70% to 2.2%
c) 0.10% to 0.30%
d) 0.6% to 0.8%
Explanation: Carbon is an extremely significant material/substance in steel. There are different types of steel based on the amount of carbon present. Low carbon steels have a carbon content of 0.10% to 0.30%. High carbon steel has 0.70% to 2.2% carbon.
3. A large amount of sulphur is present in the steel.
Explanation: The above statement is incorrect. It is not possible for a large amount of sulphur to be present in steel as it is considered to be an undesirable impurity. It has to be present in less than 0.06 percentage.
4. A nickel-chromium alloy can maintain its ductility even after being heat-treated it to an ultimate tensile strength of 250,000 p.s.i.
Explanation: The above statement is true. Chromium is a very advantageous material that gives hardness, strength and corrosion resistance to steel when it is added to it. Combining it with nickel also results in good properties.
5. The amount of carbon present in wrought iron is ___________
a) 3% to 4%
b) Trace to 0.08%
c) 0.30% to 0.70%
d) 2.2% to 4.5%
Explanation: Iron and steel can be categorized based on the amount of carbon present. Wrought iron contains trace to 0.08% of carbon. Medium carbon steel contains 0.30% to 0.70% of carbon. Cast iron contains 2.2% to 4.5% of carbon.
6. Silico-manganese steels have advantageous __________ resistance.
Explanation: Steel contains a very low amount of silicone. Less than 0.3%. The ductility of metal can increase by the addition of a small quantity of silicon. Silico-manganese steels have an advantageous impact resistance.
7. A material that requires __________ heat-treatment is preferred over a material that requires a ___ of heat-treatment.
a) less, higher amount
b) a high, lower amount
c) a moderate, lower amount
d) high, no amount
Explanation: There are several factors that are considered while choosing the metal that has to be used in the construction of components of an aircraft. Materials requiring less heat treatment are typically preferred.
8. Mild ___________ steel is used for aircraft nuts.
Explanation: Steels are used in the construction of different components and tools of an aircraft. Mild carbon steel, also called as cold-rolled stock is used to manufacture some standard parts that also includes aircraft nuts.
9. The steel S.A.E 1025 has an ultimate tensile strength of __________
a) 12,000 p.s.i
b) 6,000 p.s.i
c) 55,000 p.s.i
d) 22,000 p.s.i
Explanation: The steel S.A.E 1025 is also called mild carbon steel and cold-rolled stock. It has an ultimate tensile strength of 55,000 p.s.i. It is bought cold-rolled for aircraft manufacturing purposes. It develops a higher strength when heat treated.
10. As the amount of carbon in steel increases, its ____________ increases.
b) impact resistance
Explanation: Addition of carbon in a substance changes its properties. When the amount of carbon present in a material increases, its hardness also increases. Ductility, impact resistance and weldability decrease.
11. As the amount of carbon in steel increases, its ___________ decreases.
a) range of heat treatment
c) ultimate strength
Explanation: Carbon combines readily with iron and is a very important component of steel. As the amount of carbon in a substance increases, its toughness decreases. Ultimate strength, hardness and range of heat treatment increase.
Sanfoundry Global Education & Learning Series – Aerospace Materials and Processes.
To practice all areas of Aerospace Materials and Processes, here is complete set of 1000+ Multiple Choice Questions and Answers.