chapter 6 Flashcards
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
C) Toughness of weld and HAZ decreases
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.
B) It is about the same overall as in freshwater but the decrease in electrical conductivity of seawater generally tends toward reducing it.
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) groove weld.
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) Thick T-groove welds
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) can occur in many areas of the weld.
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.
D) ferrite and austenite.
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
B) a short weld pool with solidifying crystals growing from the back of the pool
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
D) 20% filler and 80% base
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) thick plates and groove welds.
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) Zone I
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)
D) 38 mm (1-1/2 in)
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.
re-baked at temperatures between 230 °C and 260 °C.
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
D) Copper
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.
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
C) The welding process
Which of the following processes generate the highest rate of dilutiion? (Multiple Choice)
Question options:
A) GTAW
B) SMAW
C) SAW
D) GMAW
A) GTAW
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
C) By increasing the welding speed and current
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
B) The extent to which they grow depends on the energy input.
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.
B) involving large diameter electrodes with high currents.
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
Zone II
Why is it possible for some multipass welds to have a higher toughness than a single pass weld
The passes in the multipass weld refine the underlying grain structure
Which of the following joints will provide the most dilution
A square groove weld with zero root opening
What size of grains are highly recommended for low temperature applications
Small grains
Welding Institute of Canada developed a test specifically for
ferrite and austenite.
pipeline steel
thick t-groove welds
electroslag welding
pipeline steel
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
weld metal zone
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.
- The weld metal cooling rate is usually much more rapid than that of a plate after rolling at the mill
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
lower the upper shelf Charpy energy
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
Steels containing less expensive alloying elements
s it a good practice to replace welding procedures for cracking tests? Yes or no
Choose matching definition
1
Yes
2
No
No
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
Gas tungsten arc welding
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 fine grain structure
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
it occurs below a temperature of around 150 °C
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.
The joint tensile strength will be reduced
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
small ASTM grain size numbers
