RK7-1 task 2

Question 1

while you weld, the difference in temperature between the weld itself and the area immediately surrounding it may be as great as

1. 400°C (932°F)
2. 750°C (1382°F)
3. 1000°C (1832°F)
4. 2000°C (3632°F)

Answer 1

c. 1000°C (1832°F)

Question 2

there are four basic zones in and around a weld. They are

1. blue zone, weld zone, heat affected zone, adjacent zone
2. heat affected zone, fusion zone, weld zone, brittle zone
3. heat affected zone, weld zone, fusion zone, adjacent zone
4. fusion zone, martensite zone, heat affected zone, adjacent zone

Answer 2

c. heat affected zone, weld zone, fusion zone, adjacent zone

Question 3

the admixture of carbon from the base metal during welding is one reason why the root pass is often more ______ than later passes.

1. ductile
2. tough
3. plastic
4. brittle

Answer 3

d. brittle

Question 4

the heat affected zone is given that name because

1. it gets hot and that is all
2. it is not affected in any permanent way
3. the heat it absorbs affects others zones
4. the heat it absorbs changes its structure

Answer 4

d. the heat it absorbs changes its structure

Question 5

thick base metal will draw way welding heat ______ thin base metal.

1. more slowly than
2. more quickly than
3. more erratically than
4. at the same rate as

Answer 5

b. more quickly than

Question 6

what type of grain structure do single pass welds tend to form as they solidify?

1. ductile
2. coarse columnar
3. austenitic
4. fine

Answer 6

b. coarse columnar

Question 7

In multi-pass welds, later passes recrystallize the grains in the earlier passes and also

1. relieve stresses
2. remove impurities
3. increase the cooling rate
4. equalize heat input

Answer 7

a. relieve stresses

Question 8

the metallurgical advantage of multi-pass welds over single pass welds is

1. a harder structure
2. more grain refinement
3. decrease ductility
4. a coarser grain structure

Answer 8

b. more grain refinement

Question 9

cracking in a weld is the result of

1. only mechanical factors such as joint restraint
2. only metallurgical factors such as embrittlement
3. either mechanical or metallurgical factors
4. High atmospheric pressure

Answer 9

c. either mechanical or metallurgical factors

Question 10

cracks that penetrate the base metal at 90° to the weld are called

1. underbead cracks
2. radial cracks
3. toe cracks
4. root cracks

Answer 10

b. radial cracks

Question 11

preheating helps reduce the likelihood of cracking by

1. reducing the thermal conductivity of the base metal
2. reducing the tendency for martensite to form
3. removing grease, oil and scale
4. all of the above

Answer 11

d. all of the above

Question 12

two devices which can be used to maintain accurate preheat temperatures are

1. thermocouple and a pyrometer
2. thermocouple and a tempilstik
3. tempilstik and a pyrometer
4. millivoltmetre and to Tempilstik

Answer 12

c. tempilstik and a pyrometer

Question 13

in addition to relieving stresses, postheating is a means of

1. controlling the cooling rate
2. cleaning the weld
3. increasing hardness
4. improving corrosion resistance

Answer 13

a. controlling the cooling rate