Welding Efficiency & Learning Defects (W.E.L.D) Cards A

Transcription

1 Welding Efficiency & Learning Defects (W.E.L.D) Cards A

2 Ideal weld path and look for tee and butt joints Definition The proper weld filament, consistent path and fusion. Tee Joint V-Groove Joint 2

3 W.E.L.D Define, then check your welder and technique 3

4 Porosity Definition The presence of inclusions or gas pockets in a weld. Causes Improper shielding Contaminated metal Check Your Welder Adjust shielding gas flow Clean nozzle from spatter Clean diffuser from spatter Check Your Technique Keep Contact-To-Work distance ¼ to ½ Keep nozzle out of the weld puddle Clean base metal 4

5 W.E.L.D Define, then check your welder and technique 5

6 Undercut Definition A groove melted into the base metal adjacent to the toe or root of a weld and left unfilled by weld metal. Causes Improper settings Improper work angle Fast travel speed Rust Check Your Welder Decrease voltage or increase wire feed speed Check Your Technique Keep work angle around 45* for a fillet weld and 90* for a groove weld Slow down travel speed Clean base metal 6

7 W.E.L.D Define, then check your welder and technique 7

8 Overlap Definition The overhang of weld metal beyond the bond at the toe of a weld. Causes Improper settings Improper work angle Fast travel speed Rust Check Your Welder Decrease voltage or increase wire feed speed Check Your Technique Keep work angle around 45* for a fillet weld and 90* for a groove weld Slow down travel speed Clean base metal 8

9 W.E.L.D Define, then check your welder and technique 9

10 Incomplete Joint Penetration Definition When during/after a weld, the filler metal fails to penetrate and fuse with an area of the weld joint. Causes Improper settings Fast travel speed Improper work angle Too long wire stick out Improper (too steep) travel angle Improper joint penetration Check Your Welder Adjust settings for the thickness of the base metal Increase voltage if paired with overlap Increase wire feed speed if paired with undercut Check Your Technique Increase root opening Align metal in joint to be even and square Assure proper bevel angle, if necessary Keep work angle around 45* for a fillet weld and 90* for a groove weld Keep travel angle at 0* - 15* Keep contact-to-work distance ¼ to ½ Slow down travel 10

11 W.E.L.D Define, then check your welder and technique 11

12 Incomplete Fusion Definition When during a weld, the failure of a welding process to fuse, or join together, layers of weld metal or weld metal and base metal. Causes Improper settings Travel speed to fast Improper work angle Contamination base metal Improper (too steep travel angle) To long wire stick out Check Your Welder Adjust setting for the thickness of the base metal Increase voltage if bead is large and ropey Increase wire feed speed if bead is small and using proper travel speed Check Your Technique Keep work angle around 45* for a fillet weld and 90* for a groove weld Keep travel angle at 0* -15* Keep contact-to-work distance ¼ ½ Slow down travel speed Clean base metal 12

13 W.E.L.D Define, then check your welder and technique 13

14 Spatter Definition The metal particles expelled during arc and gas welding which do not form a part of the weld. Causes Improper settings Too long wire stick out Improper work angle Contaminated base metal Improper travel angle Check Your Welder Adjust settings for the thickness of the base metal Decrease voltage if paired with undercut Check Your Technique Keep work angle around 45* for a fillet weld and 90* for a groove weld Keep travel angle at 0*-15* Keep contact to work distance ¼ ½ Clean base metal 14

15 W.E.L.D Define, then check your welder and technique 15

16 Cracks Definition A narrow break in the weld metal, base metal, or the crater formed at the end of a weld bead. Causes Stress in the weld and HAZ Improper bead contour Fast cooling Improper travel speed Improper filler Improper weld termination Check Your Welder Use filler metal with a matching tensile strength and similar composition as base metal Check Your Technique Allow metal to cool on its own Preheat metal Adjust travel speed so that contour of weld is proper Pause at end of weld to fill crater 16

17 W.E.L.D Define, then check your welder and technique 17

18 Excessive Concavity or Insufficient Reinforcement Definition When the distance from the weld face perpendicular to a line joining the weld toes curves inward toward the weld joint. Causes Improper settings Fast travel speed Check Your Welder Increase wire feed speed Check Your Technique Slow down travel If multi-pass weld, weld more passes to fill 18

19 W.E.L.D Define, then check your welder and technique 19

20 Excessive Convexity or Reinforcement Definition When the distance from the weld face perpendicular to a line joining the weld toes curves outward and away from the weld joint. Causes Improper settings Slow travel speed Improper travel (too steep) angle Check Your Welder Decrease wire feed speed Check Your Technique Speed up travel If multi-pass weld, weld less passes Grind to proper size Keep travel angle at 0*-15* 20

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