Mechanical Engineering Questions And Answers :: Engineering Materials: part5

Mechanical Engineering : Engineering Materials QUESTIONS AND ANSWERS :: part5 : 1 to 5

Following Mechanical Engineering Multiple choice objective type questions and answers will help you in BSNL JTO, GATE 2021 and IES 2021 examinations :

1.Grey cast iron

contains 1.7 to 3.5% carbon in fre< state and is obtained by the slov cooling of molten cast iron
is also known as chilled cast iron am is obtained by cooling rapidly. It i: almost unmachinable
is produced by annealing process. I is soft, tough and easily machinec metal
is produced by small additions o magnesium (or cerium) in the ladle Graphite is in nodular or spheroida form and is well dispersed throughou the material
none of the above is true.

2.The hardness of steel increases if it contains

all of the above.

3.Which of the following element results in presence of free graphite in C.I.


4.Compressive strength of grey cast iron in tonnes/cm is of the order of

3- 5

5.Cobalt in steel

improves wear resistance, cuttin ability and toughness
refines grain size and produces les tendency to caricaturisation, improve corrosion and heat resistant proper ties
improves cutting ability and reduce harden ability
gives ductility, toughness, tensil strength and anti corrosion properties:
none of the above.

More Engineering Materials QUESTIONS AND ANSWERS available in next pages

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