Oxide films trapped within the weld metal Incorrect filler metal, crack sensitive parent metal, high restraint, high heat input (see Chapter 2) Incorrect welder technique, lack of crater fillĬracking in the HAZ or in previously deposited weld metal
Short longitudinal or star-shaped crack in finish crater Metal, high restraint, high heat input (see Chapter 2) Incorrect choice of filler metal, failure to control dilution, incorrect edge preparation, crack susceptible parent Incorrect welder technique - lack of crater fill May be localised, uniformly distributed or alignedĭirty consumables, poorly cleaned or dirty weld preparations, contaminated shield gas, contaminated (hydrogen containing) parent metal – especially castings, oxide film on parent metal, porous gas hoses, leaks in gas delivery system, condensation, poor joint design trapping gas (see Chapter 2)Įlongated gas cavity formed by solidification of large weld poolĮlongated cavity in the weld finish crater Gas entrapped in weld metal giving a cavity. Weld bead too large, current too high, travel speed too slow, prevalent in horiz.– vert. Weld metal that has rolled over at the edges and not fused to the parent metal. Root pass ‘sucked back’ to give a shallow grooveĬurrent too high, root gap too wide, root face too thinĬurrent too high, travel speed too slow, root face too thin, root gap too large Poor welder technique, travel speed too fast, current too low, incorrect torch positioning Insufficient weld metal fill giving groove on weld face resulting in insufficient throat Incomplete fill (face concavity or missed edge). Prevalent at top edge of PB filletĬurrent too high, travel speed too fast, incorrect torch angle, inadequate cleaning Incorrect welder technique (see Section 7.4.1), poor earthingįailure to achieve the minimum penetration specified by designĬurrent too low, travel speed too high, incorrect torch angle, incorrect weld prep.įailure of weld metal to penetrate fully root facesĬurrent too low, travel speed too fast, root face too thick, root gap too small, incorrect torch angle, misalignmentĬurrent too high, travel speed too slow, root gap too wide, root face too thin Lack of fusion beneath weld start position Root bead fully penetrated but not fused to root faceĬurrent too low, voltage too low, travel speed too high, root face too thick, root gap too wide, incorrect torch angle, inadequate cleaning surfaces, inadequate joint cleaning, weld preparation too narrowįailure of weld metal to fuse to preceding runĬurrent too low, travel speed too high, incorrect torch angle, inadequate inter-run cleaning Failure of weld metal to fuse to weld preparationĬurrent too low, travel speed too high, incorrect torch angle, oxide film on prep.
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