chapter 6 Flashcards

1
Q

During a welding procedure, the welder increases the amperage more than the indicated values. As a result of this change, what would be the effect on weld toughness? (Multiple Choice)
Question options:

A) No effect

B) Toughness of weld and HAZ increases

C) Toughness of weld and HAZ decreases

D) Grains in the HAZ would be small

A

C) Toughness of weld and HAZ decreases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What may be the effect of seawater on the corrosion of carbon steels? (Multiple Choice)
Question options:

A) The corrosion rate of steels in seawater increase exponentially.

B) It is about the same overall as in freshwater but the decrease in electrical conductivity of seawater generally tends toward reducing it.

C) The corrosion rate of steels in seawater depends entirely on the ocean and their degree of salt dissolution.

D) It is about the same overall as in freshwater but the improved electrical conductivity of seawater leads to increases in pitting attack.

A

B) It is about the same overall as in freshwater but the decrease in electrical conductivity of seawater generally tends toward reducing it.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

The Tekken test is suitable to study crack susceptibility in a: (Multiple Choice)
Question options:

A) groove weld.

B) fillet weld.

C) lap weld.

D) corner weld.

A

A) groove weld.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Lamellar tearing is most likely to occur in which of the following? (Multiple Choice)
Question options:

A) Thick T-groove welds

B) T-groove welds in thin materials

C) Large groove welds

D) Groove welds in thin material

A

A) Thick T-groove welds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Hydrogen cracking in carbon-manganese steels: (Multiple Choice)
Question options:

A) can occur in many areas of the weld.

B) can occur only on the weld surfaces.

C) can occur only in the weld root region.

D) can occur only in multi-pass welds.

A

A) can occur in many areas of the weld.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

The partially transformed area of the heat-affected zone has two types of microstructure: (Multiple Choice)
Question options:

A) martensite and ferrite.

B) pearlite and austenite.

C) gamma and delta.

D) ferrite and austenite.

A

D) ferrite and austenite.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The solidification structure that results from a slow welding speed can be described as: (Multiple Choice)
Question options:

A) an elongated weld pool with solidifying crystals growing from the sides towards each other

B) a short weld pool with solidifying crystals growing from the back of the pool

C) an elongated weld pool with solidifying crystals growing from the back of the pool

D) a short weld pool with solidifying crystals growing from the sides towards each other

A

B) a short weld pool with solidifying crystals growing from the back of the pool

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How much is the contribution of the parent material and the welding rod when welding is done with SAW in a butt joint without a gap? (Multiple Choice)
Question options:

A) 50% filler and 50% base

B) 40% filler and 60% base

C) 30% filler and 70% base

D) 20% filler and 80% base

A

D) 20% filler and 80% base

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

The restraint afforded to overall weld metal shrinkage is usually higher in: (Multiple Choice)
Question options:

A) thick plates and groove welds.

B) thick plates and fillet welds.

C) thin plates and groove welds.

D) thin plates and fillet welds.

A

A) thick plates and groove welds.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Steels can be grouped into three zones based on their carbon content and carbon equivalent. In which zone steels are not prone to hydrogen cracking? (Multiple Choice)
Question options:

A) Zone I

B) Zone II

C) Zone III

D) Zone IV

A

A) Zone I

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Beyond a certain thickness the cooling rate is independent of thickness. At what thickness does this occur in carbon-manganese steels? (Multiple Choice)
Question options:

A) 6 mm (1/4 in)

B) 2 mm (1/2 in)

C) 25 mm (1 in)

D) 38 mm (1-1/2 in)

A

D) 38 mm (1-1/2 in)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

According to CSA W59, a damaged container of low alloy SMAW electrodes must be: (Multiple Choice)
Question options:

A) re-baked at temperatures between 370 °C and 430 °C.

B) re-baked at temperatures between 230 °C and 260 °C.

C) re-baked at a temperature above 500 °C.

D) placed in a holding oven at 120 °C for 2-4 hours.

A

re-baked at temperatures between 230 °C and 260 °C.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which element is the most beneficial to steel when exposed to atmospheric corrosion? (Multiple Choice)
Question options:

A) Nickel

B) Phosphorus

C) Silicon

D) Copper

A

D) Copper

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

In some steels a very slow cooling rate may produce a: (Multiple Choice)
Question options:

A) soft, coarse grain structure with low toughness.

B) hard, fine grain structure with high toughness.

C) hard, martensitic structure with low toughness.

D) hard, martensitic structure with high toughness.

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

During welding, the proportion of heat energy that enters the plate is referred to as its efficiency. What is this efficiency dependent on? (Multiple Choice)
Question options:

A) The welding current

B) The welding voltage

C) The welding process

D) The hydrogen content of the electrode

A

C) The welding process

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which of the following processes generate the highest rate of dilutiion? (Multiple Choice)
Question options:

A) GTAW

B) SMAW

C) SAW

D) GMAW

A

A) GTAW

17
Q

A welding engineer/technologist wants to change a DC weld procedure to maintain energy input but increase penetration, How would this be achieved? (Multiple Choice)
Question options:

A) By decreasing the welding speed and increasing the voltage

B) By maintaining the same current but using a larger wire diameter

C) By increasing the welding speed and current

D) By increasing the arc voltage and selecting AC current

A

C) By increasing the welding speed and current

18
Q

In the heat affected zone, regions that are close to the fusion boundary can experience temperatures sufficiently high that growth of the austenite grains occurs. What governs this growth? (Multiple Choice)
Question options:

A) The extent to which they grow depends on the welding process.

B) The extent to which they grow depends on the energy input.

C) Their growth depends on the steel alloy content and the welding process.

D) Their growth depends on the thickness of the steel, the welding process and the alloy content

A

B) The extent to which they grow depends on the energy input.

19
Q

For applications where it is necessary to maintain good fracture toughness, a fine grain structure must be achieved by using welding procedures: (Multiple Choice)
Question options:

A) involving electrodes or fluxes that are acidic in nature.

B) involving large diameter electrodes with high currents.

C) that minimize welding speed and give large beads.

D) placing a limit on the energy input of the process.

A

B) involving large diameter electrodes with high currents.

20
Q

Steels can be grouped into three zones based on their carbon content and carbon equivalent. The HAZ hardness of which group of steels can be controlled by cooling rate

A

Zone II

21
Q

Why is it possible for some multipass welds to have a higher toughness than a single pass weld

A

The passes in the multipass weld refine the underlying grain structure

22
Q

Which of the following joints will provide the most dilution

A

A square groove weld with zero root opening

23
Q

What size of grains are highly recommended for low temperature applications

A

Small grains

24
Q

Welding Institute of Canada developed a test specifically for

ferrite and austenite.
pipeline steel
thick t-groove welds
electroslag welding

A

pipeline steel

25
Q

The most predominant cracking in high strength low alloy steel (HSLA) is in the

gas tungsten arc welding
weld metal zone
haz
thick t-groove welds

A

weld metal zone

26
Q

What is the difference between weld metal microstructure in a carbon steel and the parent plate

  • There is a reheating effect in multipass welds where the heat from one pass refines the grains of the previous passes
  • Control the depth to width ratio of weld beads in the range 0.5-1.0
  • The weld metal cooling rate is usually much more rapid than that of a plate after rolling at the mill
  • In the area of mixed microstructure and at the unaffected base metal border.
A
  • The weld metal cooling rate is usually much more rapid than that of a plate after rolling at the mill
27
Q

increased oxygen content of a weld is likely to
Choose matching definition
1
the slower the weld Cooling rate
2
soft, coarse grain structure with low toughness
3
for precipitation strengthening and Grain refinement
4
lower the upper shelf Charpy energy

A

lower the upper shelf Charpy energy

28
Q

What is the meaning of lean steels
Choose matching definition
1
Steels containing less expensive alloying elements
2
Set through nozzles in thick plate
3
The slower the weld cooling rate
4
Higher preheat temperatures for thicker plates

A

Steels containing less expensive alloying elements

29
Q

s it a good practice to replace welding procedures for cracking tests? Yes or no
Choose matching definition
1
Yes
2
No

A

No

30
Q

Which of the following arc welding processes is the least efficient
Choose matching definition
1
Copper
2
Gas tungsten arc welding
3
Pipeline steel
4
Tig welding

A

Gas tungsten arc welding

31
Q

Good fracture toughness normally requires
Choose matching definition
1
small astm grain size numbers
2
Gas tungsten arc welding
3
small grains
4
a fine grain structure

A

a fine grain structure

32
Q

Which of the following is a feature of the cracking mechanism known as hydrogen embrittlement
Choose matching definition
1
In the area of mixed microstructure and at the unaffected base metal border.
2
it occurs below a temperature of around 150 °C
3
Set through nozzles in thick plate
4
Gas tungsten arc welding

A

it occurs below a temperature of around 150 °C

33
Q

With stress relief heat treatment, what material properties can be expected to change from the as-welded product
Choose matching definition
1
The joint tensile strength will be reduced
2
The slower the weld cooling rate
3
Crack delay
4
The energy input.

A

The joint tensile strength will be reduced

34
Q

High energy input welds typically result in
Choose matching definition
1
small grains
2
small ASTM grain size numbers
3
a fine grain structure
4
saw

A

small ASTM grain size numbers

35
Q
A