Safety, Tools, Weld Faults & OAW Flashcards
Of previously listed weld faults, which is considered the most serious? Explain your answer.
Cracking. Cracks continue to propagate leading to complete failure of the weld.
For each term, answer whether it is a dimensional, a structural discontinuity or defective property.
A) overlap\_\_\_\_\_\_\_\_\_\_ B) insufficient root opening\_\_\_\_\_\_\_\_\_\_ C) lack of fusion \_\_\_\_\_\_\_\_\_\_ D) warping \_\_\_\_\_\_\_\_\_\_ E) filler metal composition \_\_\_\_\_\_\_\_\_\_ F) excessive reinforcement \_\_\_\_\_\_\_\_\_\_ G) incorrect joint preparation \_\_\_\_\_\_\_\_\_\_ H) incorrect weld size \_\_\_\_\_\_\_\_\_\_ I) excessive hardness \_\_\_\_\_\_\_\_\_\_ J) undercut \_\_\_\_\_\_\_\_\_\_ K) cracking \_\_\_\_\_\_\_\_\_\_ L) porosity \_\_\_\_\_\_\_\_\_\_ M) insufficient tensile strength \_\_\_\_\_\_\_\_\_\_ N) slag inclusions \_\_\_\_\_\_\_\_\_\_ O) stray arc strikes \_\_\_\_\_\_\_\_\_\_ P) poor weld profile \_\_\_\_\_\_\_\_\_\_
A) overlap = dimensional B) insufficient root opening = dimensional defect before welding C) lack of fusion = structural D) warping = dimensional E) filler metal composition = defective F) excessive reinforcement = dimensional G) incorrect joint preparation = dimensional H) incorrect weld size = dimensional I) excessive hardness = defective J) undercut = dimensional defect after welding K) cracking = structural L) porosity = structural M) insufficient tensile strength = defective N) slag inclusions = structural O) stray arc strikes = structural P) poor weld profile = dimensional
Cutting a notch into both ends of a weld and applying force against one end is known as a:
A) stress flow test.
B) weld fault test.
C) weld press test.
D) nick break test.
D) nick break test.
Notch effect in a weld has stress flow lines:
A) concentrated at one point.
B) flowing from left to right.
C) flowing smoothly through the welded joint.
D) stretched beyond the elastic limit.
A) concentrated at one point.
A tapered transition ratio 3 : 1 when joining plates of different thicknesses would:
A) waste time and energy.
B) decrease notch effect.
C) decrease cross-section strength.
D) create a point of high stress.
B) decrease notch effect.
A high concentration of stress in a weld causes:
A) stress flow.
B) high strength.
C) a notch effect.
D) a nick break.
C) a notch effect.
List (3) weld faults that may be caused by each of the following:
A) inadequate heat input: ______________________________
B) excessive heat input: ______________________________
C) incorrect electrode angle: ______________________________
D) travel speed too slow: ______________________________
E) travel speed too fast: ______________________________
F) contaminated joint area (rust, scale, oil, paint, etc.) ______________________________
A) inadequate heat input: slag inclusions, lack of fusion, incomplete penetration
B) excessive heat input: cracking, undercut, excessive penetration
C) incorrect electrode angle: undercut, overlap, lack of fusion
D) travel speed too slow: overlap, excessive convexity, excessive penetration
E) travel speed too fast: cracking, lack of fusion, slag inclusions, incomplete penetration
F) contaminated joint area (rust, scale, oil, paint, etc.): porosity, slag inclusions, lack of fusion, cracking
An insufficient root opening on a groove weld is likely to cause:
A) lack of penetration
B) excessive penetration
C) complete fusion
D) stray arc strike
A) lack of penetration
Which of the following variables would be effective in controlling excessive penetration on a groove weld?
A) reduce the land thickness
B) increase the bevel angle
C) decrease the root opening
D) pre-set the plates to widen the groove opening
C) decrease the root opening
Porosity in a weld can help be reduced by:
A) cleaning the joint area before welding
B) welding with stringer beads instead of weave beads
C) maintaining a fast travel speed with the electrode
D) avoiding the use of low hydrogen type electrodes
A) cleaning the joint area before welding
Undercut is most commonly caused by:
A) current setting to high
B) travel speed too fast
C) using high iron powder electrodes
D) incorrect electrode angle
D) incorrect electrode angle
Distortion can be controlled by:
A) making several passes using a small electrodes at a low current settings.
B) using a long arc length
C) using low hydrogen type electrodes
D) maintaining ac accurate joint fit up
C) using low hydrogen type electrodes
Which of the following can cause a quenched and brittle condition in metal?
A) a stray arc strike
B) welding current set too low
C) an inadequately filled crater
D) using a damp electrode
A) a stray arc strike
Which situation would most likely produce slag inclusions in multi-pass welds?
A) high current setting with a short arc length
B) high current setting with a normal arc length
C) low current setting with a short arc length
D) removing the slag between passes
C) low current setting with a short arc length
Longitudinal cracks in a weld can be caused by:
A) excessive travel speed
B) excessive joint restraint
C) arc length too long
D)incorrect electrode inclination
B) excessive joint restraint
