rk7-1 task 1

Question 1

materials can exist in four forms: solid, liquid, plasma and

1. inert
2. atom
3. BCC
4. gas

Answer 1

d. gas

Question 2

the process of welding metals is similar to the process of their original production because of the similarity in the

1. elements
2. filler materials
3. ingots
4. physical conditions

Answer 2

d. physical conditions

Question 3

when metal solidifies it takes on a characteristic pattern. It forms into a crystalline needle pattern that resembles small pine trees, this structure is called

1. slip
2. twinning
3. dendrite
4. axes

Answer 3

c. dendrite

Question 4

at lower temperatures the strength of grain boundaries are

1. greater than the grains next to them
2. less than the grains next to them
3. the same as the grains next to them
4. unstable

Answer 4

a. greater than the grains next to them

Question 5

the ability of a metal to exist in more than one crystalline form is called

1. dendrite
2. BCC
3. FCC
4. allotropy

Answer 5

d. allotropy

Question 6

the finesse or coarseness of the grain structure of the solid metal is chiefly the result of the

1. temperature to which it is heated
2. speed at which cools
3. atmospheric pressure during cooling
4. process used to manufacture

Answer 6

b. speed at which cools

Question 7

a fine grain steel would be _______ than coarse grained steel.

1. stronger
2. weaker
3. heavier
4. lighter

Answer 7

a. stronger

Question 8

the welding process can alter the grain size

1. true
2. false

Answer 8

a. true

Question 9

when cooled very quickly from a high temperature what kind of structure will carbon steel take on?

1. ferritic
2. austenitic
3. pearlite
4. martensitic

Answer 9

d. martensitic

Question 10

when cooling iron reaches the Curie point it becomes

1. magnetic
2. non-magnetic
3. a combination of magnetic and non-magnetic
4. electromagnetic

Answer 10

a. magnetic

Question 11

up to 4.3% the carbon in molten steel will

1. increase the eutectoid
2. reduce the eutectoid
3. lower the temperature at which freezing occurs
4. increase the temperature at which freezing occurs

Answer 11

c. lower the temperature at which freezing occurs

Question 12

the solution of carbon and iron is called

1. dendrite
2. kryptonite
3. austenite
4. martensite

Answer 12

c. austenite

Question 13

pearlite is a layered combination of pure iron and

1. cementite
2. austenite
3. dendrite
4. martensite

Answer 13

a. cementite

Question 14

locate the following on the phase diagram in Figure 1

1. ___ eutectic point
2. ___ liquid
3. ___ solid
4. ___ mushy stage
5. ___ eutectoid point

Answer 14

1. B eutectic point
2. C liquid
3. E solid
4. A mushy stage
5. D eutectoid point