Weld defects Flashcards
D
Defect definition
An amount of weld irregularities which exceed the limit of quality control
Discontinuity definition
An acceptable amount of weld irregularities within limits of quality control
Inadequate penetration definition
The weld metal fails to extend completely through the joint thickness
Inadequate penetration cause
Incorrect rod angle, inadequate amperage, inadequate gap or land
Excessive penetration definition
Weld metal exceeds allowable limit of penetration by quality control usually over 1/8
Excessive penetration cause
Excessive amperage, incorrect rod angle, excessive gap or land, feeding to much wire
Insufficient fill definition
Fill places in a v groove which is more than 1/16 below flush
Insufficient fill cause
Incorrect: bead placement, size, travel speed
Internal undercut definition
Gouging or cutting away of the base metal on the root side of metal
Internal undercut cause
Insufficient metal prep, excessive amperage, rod angle, long arching
Wagon tracks definition
Two black parallel lines of slag trapped on each side of root next to bevel 6010 root
Wagon tracks cause
Incorrect method of grinding
Unbroken land definition
Weld metal fails to extend completely through the land thickness, lack of melt through on root pass
Unbroken land cause
Usage of incorrect, rod angle, amperage, gap and or land
Off set and or high-low definition
Incorrect internal alignment of pipe or uneven plates
Off set and or high-low cause
Incorrect alignment while tacking, pipe with two different ID inside diameter
Incomplete fusion definition
Lack of fusion between filler metal and the base metal, inadequate coalescence of molecules
Incomplete fusion cause
Amperage too low, travel speed too fast, improper joint design
Tungsten inclusion definition
Random pieces of unmelted tungsten electrode that are trapped in the weld
Tungsten inclusion cause
Placing the tungsten electrode into the molten weld metal. Generally happens with inexperience
Slag inclusion definition
A non metal substance of irregular shape that is trapped in weld area
Slag inclusion cause
Improper bead placement, insufficient cleaning, improper joint design
Porosity definition
Gas pockets trapped in weld area
Porosity cause
Cracked or missing flux, wind, improper rod angle, moisture, lack of shielding gas
Burn thru definition
Melting or burning through hot pass
Burn they cause
Grinding root to thing, long arching, excessive amperage
