typical welding faults - lief sent

7/27/2019 Typical Welding Faults - LIEF Sent

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TYPICAL WELDINGFAULTS


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Typical Welding Faults

Root faults

Fusion faults

Slag inclusions

Pores

Cracks

Unmelted

edgeUndercutt


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70

2-2,5mm

35

1,5mm

Root faults Edge preparation


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Typical Welding FaultsRoot faults Amperage setting

Manipulating electrode


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Typical Welding FaultsFusion faults Amperage setting


Too low amperage setting

Edge preparation

Included angle not sufficient

90


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Typical Welding FaultsFusion faults


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Typical Welding FaultsSlag inclusions Amperage setting


Placing of runs

Not removing slag

Trapped slag

Manipulating

electrode


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Trapped slag


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Typical Welding FaultsPores Hydrogen pores

From moist electrodes

Other sources are:

Rust, oil, paint or

condensation along

welding groove

Oxygen poresLong arc or other reasons

for insufficient arc shielding

N2 N2

O2 O2


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Reinforcement:

1,6 mm for manual welding

3,2 mm for automated

welding

Bead Crown


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Stresses are distributed more uniformly through a flat

or concave fil let weld.


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Max undercut according

to ASME:

Undercut deeper than 0,8 mm

and longer than 6 mm is

unacceptable

Undercut less than 0,8 mm

but longer than 6 mm must

be evaluated form case to

case depending on

circumstances


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Heat CracksImpurities in base

materialTension across weld

Cold CracksHydrogen cracks

HAZ cracks

Shrinkage CracksLengthwise shrinkage


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Typical Welding Faults.

Spray on

Cleaner

Apply Penetrant Wipe surfaceclean

Spray onDeveloper

Inspect Defects wil l showas bright red lines

in white developer


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Typical Welding Faults.


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Magna Flux CrackDetection Kit

3 pcs. Cleaner

2 pcs. Penetrant

3 pcs. Developer

193-653535

Cleaner SKC-S

10 pcs. of 400 ML in box

193-653543

Penetrant SKL-SP1

10 pcs. of 400 ML in box

193-653550

Developer SKD-S2

10 pcs of 400 ML in box

193-653568


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INSPEKSJON AV SVEISEARBEID

FR SVEISINGEr grunnmaterialet i henhold til spesifikasjon? Kvalitet

Type

Dimensjon

Primer

Er overflaten fri for rust, olje, fett eller annen forurensning?Er materialflatene rette/i fasong, og uten skr?

Er fugeforbindelsen i henhold til spesifikasjon? ( vinkler, nesehyde, rotpning)

Er sveisemetoden i henhold til spesifikasjon? (Elektroder,TIG,MIG/MAG,UP)

Er tillsettmaterialet ( Elektroder, trd, pulver ) I henhold til spesifikasjon? (AWS,EN)

Er tilsettet godkjent i klasseselskap? (DNV,ABS,BV,GL,LR)Er gradering korekt? ( 3Y H10 for skrogkvalitet stl )

Er godkjennelsen oppdatert?

Har tilsettmaterialet blitt lagret korekt?

Elektroder,trd og pulver skal lagres i upnede

originale forpakninger

15- 25C Max 50% Relativ fukt ighet>25C Max 40% Relativ fuktighet

Er det krav t il forvarming av t ilsettet fr sveising?

Basiske og rustfrie elektroder kan for kritiske

aplikasjoner forvarmes til 300- 350C i 2 timerHar sveiseren den ndvendige kompetanse/ Godkjennelse?


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PRIOR TO WELDINGIs the base material according to specification? Quality

Type

Dimension

Primer

Is the surface free for rust, oil, grease or any other contamination?Is the material straight/ the right shape, and without cuts?

Is the edge preparation according to specif ication? ( angels, root face, root opening)

Is the welding method according to specif ication? (Electrode,TIG,MIG/MAG,UP)

Is the consumable( Electrodes, wire, flux ) according to specification? (AWS,EN)

Is the consumable approved by the classification society? (DNV,ABS,BV,GL,LR)Is the grading to standard? ( 3Y H10 for ship quality steel )

Is the approval up to date?

Has the consumable been correctly stored?

Electrodes, wire and f lux must be stored in unopened original containers

15- 25C Max 50% Relative humidity>25C Max 40% Relative humidity

Is there a requirement for re-drying of consumables before use?

Basic and stainless electrodes can for crit ical applications be heated to

300- 350C for 2 hoursDos the welder have the necessary approval for the work at hand?

INSPECTION OF WELDED JOINTS


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INSPEKSJON AV SVEISEARBEID

UNDER SVEISINGEr det krav til forvarming av grunnmaterialet fr sveising?( Ce + Tykkelse)

Kontroller at sveiseparameterne er i henhold til sveiseprosedyren

(polaritet, ampere, vol t etc)

Blir mellomlagstemperaturen overholdt? ( interpas temperature )

Ved flerlags sveis, sjekk rotstrengen for full gjennombrenningInspiser hvert lag fr neste lag ( pse god rengjring mellom lagene)

Er det krav til varmebehanling etter sveising?

ETTER SVEISING

Kontroller sveisens overflate for sprekker, porer, slagginnslutninger,underkutt samt at endekratere er fylt.

Kontroller dimensjonelle variasjoner ved hjelp av skyvelret

Kontroller A- ml for: Oversveising

Undersveising

Kontroller likebenhet

Kontroller konveksitet

Maks underkutt I henholdtil ASME:

Underkutt dypere en 0,8 mm

og lenger en 6 mm er

uakseptabelt

Underkutt mindre en 0,8 mmmen lenger en 6 mm m

vurderes fra sak t il sak

avhengig av forholdene

Overhyde:1,6 mm for manual sveising

3,2 mm for automatisert

sveisingFlat eller konkav Konveks

Underkutt


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Max undercut according toASME:

Undercut deeper than 0,8

mm and longer than 6 mm

is unacceptable

Undercut less than 0,8 mmbut longer than 6mm must

be evaluated from case to

case

Reinforcement:

1,6 mm for manual welding

3,2 mm for mechanized

weldingFlat or concave Convexity

Undercut

INSPECTION OF WELDED JOINTS

DURING WELDINGIs there a requirement for pre-heating of base material before welding?(Ce + thickness)

Control that the welding parameters are in accordance with the welding

procedure (polarity, amperage, voltage)

Are the interpass temperature requirements followed ?

When doing mult i-layer welding, check that the root run have fullpenetration

Inspect every run before next run ( clean for slag between layers)

Is there a requirement for post weld heat treatment?

AFTER WELDINGInspect the weld surface for cracks, porosity, slag inclusions,

undercut and that end crater is f illed.

Check dimensional variations using a welders gauge

Check that reinforcement is sufficient but not to high

Check equal leg length

Check for convexity

typical welding faults - lief sent

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