exam 3

Question 1

Of the following steels, the one with the highest maximum hardness is?

Answer 1

a steel with 1 weight percent carbon

Question 2

true or false. if cooling is too rapid, it is possible to surpress the formation of phases predicted by an equilbrium phase diagram.

Answer 2

true

Question 3

What has the higher yield strength, an alloy that is cold worked 25% or 35%

Answer 3

35%

Question 4

Which would have a higher yield strength, an alloy that was cold rolled 25% or hot rolled 25%

Answer 4

cold rolled 25%

Question 5

true or false. The strength of a precipitation hardened alloy is lower than that of an as-solidefied alloy

Answer 5

false

Question 6

Why is mertensite ever used in the as-quenched condition?

Answer 6

because it is too brittle

Question 7

What is the heat -treatment it is given after quenching is called?

Answer 7

Tempering

Question 8

true or false. The formation of a glass in ceramics is predicted by the phase diagram

Answer 8

false

Question 9

true or false. The strength of a precipitation hardened alloy is lower than that if an as-solidified alloy.

Answer 9

false

Question 10

What is the most probable decomposition product from austenite in a very slow cooled steel or cast iron.

Answer 10

pearlite

Question 11

ture or false. Martensite forms when austenite is cooled very quickly in a steel or cast iron

Answer 11

true

Question 12

true or false. Martensite does not form by a diffusional process

Answer 12

true

Question 13

True or false. In general the strength of steel increases as ther carbon concentration decreases

Answer 13

False

Question 14

What mechanical properties increase during cold working.

Answer 14

Ultamite tensile strength, 0.2% offset yield strength, and hardness

Question 15

What are the three phases of heat treatment

Answer 15

1. solutionize
2. quench
3. age

Question 16

What is true for the recovery stage of annealing?

Answer 16

the corrosion resistance increases and the residual stress increases

Question 17

What alloys are eutectic a and b at room temperature

Answer 17

1. 30% and 70%
2. 71.9% and 28.1%
3. 80% and 20%

Question 18

What increases the modulus of a metal

Answer 18

neither cold or hot working

Question 18

What increases the hardness of a metal

Answer 18

cold working

Question 19

What will close up porosity in a metal

Answer 19

both cold and hot working

Question 20

What will give residual stress in a metal

Answer 20

both cold and hot working

Question 21

What will give significant texture in a material

Answer 21

cold working

Question 22

What will give recovery of electrical conductivity

Answer 22

recovery

Question 23

What will give reduction in residual stress

Answer 23

recovery

Question 24

What will give better surface finish

Answer 24

cold working

Question 25

Which gives the greatest change in mechanical properties

Answer 25

recrystallization

Question 26

What structure is most likely to form in a steel that is slowly cooled through the eutectoid

Answer 26

pearlite

Question 27

Which crve represents a faster cooling rate and a higher undercooling

Answer 27

curve a

Question 28

Which transformation that occurs during cooling through the eutectoid in steel would occur with the highest quench rate

Answer 28

martensite

Question 29

Which transformation that occurs during cooling through the eutectoid in steel would occur with the highest hardness

Answer 29

martensite

Question 30

Would a hot worked 30% or cold worked 20% plate have a higher yield strength?

Answer 30

cold worked 20%

Question 30

Would a hot worked 30% or cold worked 20% plate have a higher ultamite tensile strength?

Answer 30

cold worked 20%

Question 30

Would a hot worked 30% or cold worked 20% plate have a higher hardness?

Answer 30

Cold worked 20%

Question 31

Would a hot worked 30% or cold worked 20% plate have a higher tensile modulus?

Answer 31

they would have the same

Question 32

Would a hot worked 30% or cold worked 20% plate have the best corrosion resistance?

Answer 32

hot worked 30%

Question 33

What direction would have the highest strength before rolling

Answer 33

they would have the same