Chapter Four Quiz Flashcards
The longitudinal free shrinkage of a welded butt joint in steel plate produces?
High tensile stress longitudinally across the weld.
Distortion in structural shapes with eccentric weld joints will produce which type of distortion?
Bending.
A piece of material that has restricted expansion and restricted contraction is said to be?
Restrained.
Residual stresses in the outer portions of hot rolled structural shapes are?
Compressive. First to cool.
In order to square a distorted welded frame, the flame straightening heat should be applied?
On outside of lower angle and inside of the higher angle corner.
The neutral axis of a welded fabrication is defined as?
Axis through center of gravity.
Residual stress is produced by?
Localized heating, causing an upset.
What would be the thermal expansion of a steel bar that is heated at 200 ᵒC?
0.00236m.
A plate was heated uniformly throughout and was left on top of a table to cool down. What would happen to the plate?
Plate would have same dimension as before it was heated.
Is there any correlation between the neutral axis and the centre of gravity of the cross-section of the shape?
Yes.
Flame straightening involves:
Locally heating the weldment to produce contraction.
The coefficient of thermal expansion of a material is considered a/an:
Physical property.
Which type of distortion is likely to be produced by a butt weld in long thin material? Select all that apply:
Longitudinal buckling and longitudinal shrinkage.
Restricted contraction may set up internal tensile stresses enough to cause failure if the metal is not ductile enough to accommodate the deformation.
True.
For a given plate thickness, the distortion is less for a double V groove compared to a single V groove because:
The double V is balanced about the neutral axis.
Which of the following will produce the least angular distortion in a fillet joint?
Single pass welding.
To achieve proper dimensions, the general rule for cutting shapes from plate is:
Workpiece must be kept with remaining large plate until last cut.
Back step welding on long seam joints, is a technique used to?
Reduce the extent of distortion.
The temperature reached during flame straightening must?
Be high enough to produce upset.
Which are the major factors that affect transverse shrinkage in butt welds?
Plate thickness, root opening, cross section area of weld and groove angle.
