chapter 4 Flashcards

1
Q

Shrinkage, tranverse and longitudinal
Angular distortion* caused by transverse shrinkage
Bending distortion caused by longitudinal shrinkage
Buckling caused by longitudinal shrinkage, and to a minor degree transverse shrinkage. It most often occurs when welding large, thin plates and sheets.

A
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2
Q

Is it recommended to apply stress relief following mechanical straightening? Yes or no. (Multiple Choice)
Question options:

A) Yes

B) No

A

A) Yes

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2
Q

Which of the following will produce the least angular distortion in a fillet joint?

Welding with low travel speed

Incorrect Response
Welding with high travel speed

Multi-pass welding

Single pass welding

A

Single pass welding

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3
Q

In the application of a V heating technique for flame straightening, the initial flame should be located: (Multiple Choice)
Question options:

A) in the narrow part of the V heating area first and progress slowly to the wider portion.

B) in either location to obtain the same results.

C) in the wider part of the V heating area first.

D) in the middle of the V area first.

A

A) in the narrow part of the V heating area first and progress slowly to the wider portion.

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4
Q

The longitudinal residual stress in a butt welded joint is: (Multiple Choice)
Question options:

A) low tensile.

B) high compressive.

C) high tensile.

D) low flexural.

A

C) high tensile.

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5
Q

When automatic oxy-fuel gas cutting a strip from one edge of a plate distortion will occur. Why? (Multiple Choice)
Question options:

A) Uneven heating by automatic travel uniformly expands the cut edge

B) Uneven heating by automatic travel expands the edge next to the cut

C) Uneven heating by automatic travel contracts the edge next to the cut

D) Uneven heating by automatic travel shortens the edge next to the cut

A
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6
Q

The purpose of peening the weld metal is to: (Multiple Choice)
Question options:

A) produce tensile residual stresses on the surface.

B) produce compressive residual stresses on the surface.

C) smooth out the weld ripples.

D) produce contraction of the weld metal.

A

B) produce compressive residual stresses on the surface.

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7
Q

The type of heat pattern used to curve a wide flange beam is: (Multiple Choice)
Question options:

A) line.

B) spot.

C) strip.

D) vee.

A

D) vee.

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8
Q

What are the forces exerted by the surrounding material at the spot heated zone? (Multiple Choice)
Question options:

A) Expansion

B) Yield force

C) Compression

D) Thermal expansion

A

A) Expansion

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9
Q

Is residual stress readily visible and measurable? Yes or no. (Multiple Choice)
Question options:

A) Yes

B) No

A

B) No

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10
Q

When using heat spots or wedges, it is a good practice to____________ (Multiple Choice)
Question options:

A) apply heat to the bottom of the part to allow gravity to straighten it.

B) apply heat to the short side of a curved object to stretch it.

C) apply heat to the inside of a curved object to stretch it.

D) apply heat to the long side of a curved object to shrink it.

A

D) apply heat to the long side of a curved object to shrink it.

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11
Q

The welding of seams: (Multiple Choice)
Question options:

A) should be carried up to, or beyond, an unwelded butt joint.

B) must be completed 300 — 400 mm beyond an unwelded butt joint.

C) should be stopped 300 — 400 mm short of an unwelded butt joint.

D) must be welded complete before an unwelded butt joint is started.

A

C) should be stopped 300 — 400 mm short of an unwelded butt joint.

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12
Q

The best area to produce the first tack weld in butt joints in hollow sections to be welded with the SMAW process is: (Multiple Choice)
Question options:

A) where the root opening is the largest.

B) where the root opening is the smallest.

C) where the root opening is intermediate.

D) None of the above

A

B) where the root opening is the smallest.

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13
Q

What is needed in order to produce a permanent upsetting of a part when heated? (Multiple Choice)
Question options:

A) Restricted contraction

B) No external restrain

C) The part needs to be free to expand

D) None of the above

A

A) Restricted contraction

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14
Q

What is the modulus of elasticity or Young’s modulus? (Multiple Choice)
Question options:

A) It is the relationship between strain and stress

B) It is the relationship between stress and strain

C) It is the relationship between ductility and strain

D) It is the relationship between hardness and toughness

A

B) It is the relationship between stress and strain

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15
Q

What is the difference between transverse shrinkage and angular distortion in a butt joint? (Multiple Choice)
Question options:

A) The width in the transverse direction is less, and in angular distortion both plates contract forming a pronounced angle

B) The width in the transverse direction is more, and in angular distortion both plates contract forming a pronounced angle

C) Both mean the same thing

D) None of the above

A

A) The width in the transverse direction is less, and in angular distortion both plates contract forming a pronounced angle

16
Q

For welded fabrications involving butt and fillet weld joints, distortion is influenced by: (Multiple Choice)
Question options:

A) completing the fillet welds before the butt welds.

B) completing the vertical welds before the flat welds.

C) completing the butt welds before the fillet welds.

D) completing the welds in thicker sections first then joints in thinner sections.

A

A) completing the fillet welds before the butt welds.

17
Q

The expansion of metal upon heating is volumetric and results in: (Multiple Choice)
Question options:

A) a shape change not reversible by removal of the external forces which caused it.

B) a shape change caused by local melting of the base material under restraint.

C) a shape change by bending, twisting, or warping due to external forces.

D) a shape change reversible by removal of the external forces that caused it.

A

D) a shape change reversible by removal of the external forces that caused it.

18
Q

When welding heavy plates it is a good idea to have a small root opening rather than butting the parts tightly together because: (Multiple Choice)
Question options:

A) if the parts are butted tightly together, the root pass will act as a hinge and increase angular distortion.

B) the small root opening will increase root penetration thereby increasing cracking resistance due to reduced contraction.

C) the small root opening will allow the plates to move together as the weld shrinks and help to prevent cracking.

D) the small root opening will allow the plates to spread apart as the weld progress and help to prevent cracking.

A

A) if the parts are butted tightly together, the root pass will act as a hinge and increase angular distortion.

19
Q

To produce sweep in a channel with the web on the outside of the curvature then: (Multiple Choice)
Question options:

A) only the web needs to be heated.

B) only the flange needs to be shortened by using vee heat.

C) only the flange needs to be heated by block heating.

D) only the web needs to be vee heated.

A

B) only the flange needs to be shortened by using vee heat.

20
Q

The dimensions and temperature change of the heated area are proportional to: (Multiple Choice)
Question options:

A) the welding speed.

B) the size of the welding electrode.

C) the size of the torch.

D) the resulting expansion and contraction.

A

D) the resulting expansion and contraction.

21
Q

Which alloys expand more after heating, mild steel or austenitic stainless steel? (Multiple Choice)
Question options:

A) Both expand uniformly

B) They expand unequally

C) Austenitic stainless steel expands more

D) Steel always expands more

A

C) Austenitic stainless steel expands more

22
Q

An increase in plate thickness will: (Multiple Choice)
Question options:

A) increase the transverse shrinkage.

B) decrease the transverse shrinkage.

C) have no effect on the shrinkage.

D) decrease the longitudinal shrinkage.

A

A) increase the transverse shrinkage.

23
Q

Mechanical straightening requires the most _____ of the material. (Multiple Choice)
Question options:

A) ductility

B) elastic strain

C) yield strength

D) thermal expansion

A

A) ductility

24
Q

What does the strain gauge measure in the stress-relaxation method? (Multiple Choice)
Question options:

A) Stress

B) Strain

C) Yield strength

D) Ductility

A

A) Stress

25
Q

Reheating of a flame formed area containing residual stresses is ineffective because: (Multiple Choice)
Question options:

A) it changes the chemistry of the part.

B) the subsequent heat stress relieves the first sequence of heating.

C) it results in plate color changes.

D) reheating is acceptable.

A

B) the subsequent heat stress relieves the first sequence of heating.

26
Q

One of the best methods to limit distortion in a stainless steel manifold is to: (Multiple Choice)
Question options:

A) submerge the main manifold in water to just below the weld joints.

B) apply a local preheat to the joints.

C) weld each attachment in sequence.

D) apply flame straightening techniques.

A

A) submerge the main manifold in water to just below the weld joints.

27
Q

The kerf area of an oxy-fuel cut edge represents an area of _________ stress. (Multiple Choice)
Question options:

A) compressive

B) shear

C) flexural

D) tensile

A

A) compressive

28
Q

Ductility is a property of a material that: (Multiple Choice)
Question options:

A) represents the outermost part of an object.

B) allows it to be moulded or shaped.

C) describes elastic strain.

D) prevents or limits movement.

A

B) allows it to be moulded or shaped.

29
Q

The unit of measurement for the coefficient of thermal expansion is: (Multiple Choice)
Question options:

A) inches in length per inches in thickness per degree Celsius (in/in/°C).

B) degrees C per foot (°/ft).

C) centimeters squared per degree Celsius (cm²/°C).

D) micrometer per metre per degree Celsius.

A

D) micrometer per metre per degree Celsius.

30
Q

Distortion in hollow section manifolds can be reduced by using: (Multiple Choice)
Question options:

A) local preheating.

B) uniform preheating.

C) strongbacks.

D) pre-setting.

A

C) strongbacks.

31
Q

Where is the best place to initiate spot heating in a bulged plate? (Multiple Choice)
Question options:

A) At the centre of the bulge

B) Anywhere

C) Second spot outside the centre

D) Never near the centre of the bulge

A

A) At the centre of the bulge

32
Q

Stress relaxation is a method used for: (Multiple Choice)
Question options:

A) compensating for the results of shrinkage stresses.

B) removing distortion.

C) predicting residual stresses.

D) measuring residual stresses.

A

D) measuring residual stresses.

33
Q

How can you use Young’s modulus for estimating compressional forces (restricted expansion) during heating a bar that has restricted expansion? (Multiple Choice)
Question options:

A) You can use it to calculate the total compressive force exerted on the bar

B) Young’s modulus is not part of the calculation

C) Young’s modulus is only useful for steel

D) Young’s modulus applies only to longitudinal distortion

A

A) You can use it to calculate the total compressive force exerted on the bar

34
Q

The final camber should not be checked until the member has cooled completely.(True/False)
Question options:
True
False

A