Mechanical Behaviour Questions and Answers – Applications of Strengthening Mechanisms

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This set of Mechanical Behaviour Interview Questions and Answers for Experienced people focuses on “Applications of Strengthening Mechanisms”.

1. Maraging steels are ____________
a) High carbon steels
b) Low alloy steels
c) Ultra high strength steels
d) Ferritic steels
View Answer

Answer: c
Explanation: Maraging steels are low carbon, high alloy steels. These are ultra-high strength steels. These consist of a martensite matrix.
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2. What is the tensile strength range for plain carbon steels?
a) 350-800 MPa
b) 90-600 MPa
c) 1000-1200 MPa
d) 130-300 MPa
View Answer

Answer: a
Explanation: Plain carbon steels have UTS in range 350 to 800 MPa. It depends on carbon content and microstructure. Heat treated low alloy steel has UTS of 1000-1200 MPa.

3. What is UTS range for cast Aluminium alloys?
a) 350-800 MPa
b) 90-600 MPa
c) 1000-1200 MPa
d) 130-300 MPa
View Answer

Answer: d
Explanation: Cast aluminum alloys have very low UTS range of 130 to 300 MPa. Wrought aluminum alloys have UTS 90-600 MPa. Within the same family, UTS range varies significantly.

4. Which alloying element doesn’t produce precipitation hardenable alloy with copper?
a) Al
b) Si
c) Ni
d) Be
View Answer

Answer: c
Explanation: Ni shows extended solid solubility in copper. So it can’t give precipitation hardening. Al, Si and Be make precipitation hardenable alloys with Cu.

5. Steels having UTS _________ or above are called high strength steels.
a) 300 MPa
b) 1000 MPa
c) 1500 MPa
d) 2000 MPa
View Answer

Answer: c
Explanation: Steels with UTS 1500 MPa or above are high strength steels. Steels which have UTS lesser than 1500 MPa are not high strength alloys.
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6. Grey iron consist of ________ graphite.
a) Spheroid
b) Soft and friable
c) Small volume
d) Blunted ended
View Answer

Answer: b
Explanation: Grey cast iron consist of graphite flakes rather spheroids. These flakes occupy the large volume. These are soft and friable.

7. Maraging steels have high strength due to _________
a) Martensitic strengthening
b) Precipitation hardening
c) Grain refinement
d) Martensitic strengthening and Precipitation hardening
View Answer

Answer: d
Explanation: Maraging steels consist of martensitic matrix and hence martensitic strengthening. Carbides of alloying elements precipitate. It causes precipitation hardening.

8. High strength materials have high _________
a) Tensile strength
b) Fatigue strength
c) Creep strength
d) Tensile and yield strength
View Answer

Answer: d
Explanation: Materials when categorized based on strength, mechanical strength is used. It consists of tensile and yield strength. This strength is more important in structural applications.

9. Higher the tempering temperature _________ is the strength value
a) Lower
b) Higher
c) Constant
d) Depending on other factors too
View Answer

Answer: d
Explanation: Considering secondary hardening, strength may increase with tempering temperature. But generally, it decreases. Because of relieve in stresses.
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10. Nickel doesn’t _____________
a) Stabilize austenite
b) Lower critical temperature
c) Form intermetallic compound
d) Lower strength
View Answer

Answer: d
Explanation: Ni stabilizes austenite in steel. It lowers critical temperature. It forms intermetallic compounds with other alloying elements and gives precipitation hardening.

11. Maraging steels have main alloying elements rare earth metals.
a) True
b) False
View Answer

Answer: b
Explanation: Maraging steels have main alloying elements Ni, Mo and Cr. These give precipitation hardening in martensite matrix.

12. What is not the reason for using low carbon steels?
a) Corrosion resistance
b) Weldability
c) Strength
d) H-embrittlement
View Answer

Answer: c
Explanation: C content improves strength in steel. While it increases corrosion and weld decay susceptibility. It causes H-embrittlement.

13. SG irons consist of nodules of graphite?
a) True
b) False
View Answer

Answer: a
Explanation: SG cast iron consists of graphite nodules in a pearlitic matrix. These are used for structural applications. Impact toughness is good in these cast irons.
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Sanfoundry Global Education & Learning Series – Mechanical Behaviour & Testing of Materials.

To practice all areas of Mechanical Behaviour for Interviews, here is complete set of 1000+ Multiple Choice Questions and Answers.

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Manish Bhojasia, a technology veteran with 20+ years @ Cisco & Wipro, is Founder and CTO at Sanfoundry. He is Linux Kernel Developer & SAN Architect and is passionate about competency developments in these areas. He lives in Bangalore and delivers focused training sessions to IT professionals in Linux Kernel, Linux Debugging, Linux Device Drivers, Linux Networking, Linux Storage, Advanced C Programming, SAN Storage Technologies, SCSI Internals & Storage Protocols such as iSCSI & Fiber Channel. Stay connected with him @ LinkedIn