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Фрагмент инструкции
803 710-A Voltage controls height and width of weld bead. Wire speed (amperage) controls weld penetration (wire speed = burn-off rate) 8-3. Holding And Positioning Welding Gun Welding wire is energized when gun trigger is pressed. Before lowering helmet and pressing trigger, be sure wire is no more than 1/2 in (13 mm) past end of nozzle, and tip of wire is positioned correctly on seam. NOTE 1 Hold Gun and Control Gun Trigger 2 Workpiece 3 Work Clamp 4 Electrode Extension (Stickout) 1/4 to 1/2 in (6 To 13 mm) 5 Cradle Gun and Rest Hand on Workpiece 2 3 5 4 90° 90° 0°-15° 45° 45° 1 0°-15° S-0421-A End View of Work Angle Side View of Gun Angle GROOVE WELDS End View of Work Angle Side View of Gun Angle FILLET WELDS Return To Table Of Contents OM-925 Page 33 8-4. Conditions That Affect Weld Bead Shape Weld bead shape depends on gun angle, direction of travel, electrode extension (stickout), travel speed, thickness of base metal, wire feed speed (weld current), and voltage. NOTE Slow FILLET WELD ELECTODE EXTENSIONS (STICKOUT) ELECTRODE EXTENSIONS (STICKOUT) GUN ANGLES AND WELD BEAD PROFILES 10° 10° GUN TRAVEL SPEED S-0634 Push Perpendicular Drag Short Normal Long Short Normal Long Normal Fast Weld bead shape depends on gun angle, direction of travel, electrode extension (stickout), travel speed, thickness of base metal, wire feed speed (weld current), and voltage. NOTE Slow FILLET WELD ELECTODE EXTENSIONS (STICKOUT) ELECTRODE EXTENSIONS (STICKOUT) GUN ANGLES AND WELD BEAD PROFILES 10° 10° GUN TRAVEL SPEED S-0634 Push Perpendicular Drag Short Normal Long Short Normal Long Normal Fast 8-5. Gun Movement During Welding Normally, a single stringer bead is satisfactory for most narrow groove weld joints; however, for wide groove weld joints or bridging across gaps, a weave bead or multiple stringer beads works better. NOTE 1 Stringer Bead . Steady Movement Along Seam 2 Weave Bead . Side To Side Movement Along Seam 3 Weave Patterns Use weave patterns to cover a wide area in one pass of the electrode. S-0054-A 3 1 2 8-6. Poor Weld Bead Characteristics 2 34 1 Large Spatter Deposits 2 Rough, Uneven Bead 1 3 Slight Crater During Welding 4 Bad Overlap 5 Poor Penetration 5 S-0053-A 8-7. Good Weld Bead Characteristics 1 Fine Spatter 2 Uniform Bead 3 Moderate Crater During Welding Weld a new bead or layer for each 1/8 in (3.2 mm) thickness in metals being welded. 4 No Overlap 5 Good Penetration into Base Metal S-0052-B 2 3 1 4 5 Return To Table Of Contents OM-925 Page 35 8-8. Troubleshooting . Excessive Spatter Excessive Spatter . scattering of molten metal particles that cool to solid form near weld bead. S-0636 Possible Causes Corrective Actions Wire feed speed too high. Select lower wire feed speed. Voltage too high. Select lower voltage range. Electrode extension (stickout) too long. Use shorter electrode extension (stickout). Workpiece dirty. Remove all grease, oil, moisture, rust, paint, undercoating, and dirt from work surface before welding. Insufficient shielding gas at welding arc. Increase flow of shielding gas at regulator/flowmeter and/or prevent drafts near welding arc. Dirty welding wire. Use clean, dry welding wire. Eliminate pickup of oil or lubricant on welding wire from feeder or liner. Incorrect polarity. Check polarity required by welding wire, and change to correct polarity at welding power source. 8-9. Troubleshooting . Porosity Porosity . small cavities or holes resulting from gas pockets in weld metal. S-0635 Possible Causes Corrective Actions Insufficient shielding gas at welding arc. Increase flow of shielding gas at regulator/flowmeter and/or prevent drafts near welding arc. Remove spatter from gun nozzle. Check gas hoses for leaks. Place nozzle 1/4 to 1/2 in (6-13 mm) from workpiece. Hold gun near bead at end of weld until molten metal solidifies. Wrong gas. Use welding grade shielding gas; change to different gas. Dirty welding wire. Use clean, dry welding wire. Eliminate pick up of oil or lubricant on welding wire from feeder or liner. Workpiece dirty. Remove all grease, oil, moisture, rust, paint, coatings, and dirt from work surface before welding. Use a more highly deoxidizing welding wire (contact supplier). Welding wire extends too far out of nozzle. Be sure welding wire extends not more than 1/2 in (13 mm) beyond nozzle. 8-10. Troubleshooting . Excessive Penetration Good Penetration Excessive Penetration . weld metal melting through base metal and hanging underneath weld. Excessive Penetration S-0639 Possible Causes Corrective Actions Excessive heat input. Select lower voltage range and reduce wire feed speed. Increase travel speed. OM-925 Page 36 Return To Table Of Contents 8-11. Troubleshooting . Lack Of Penetration Lack of Penetration Lack Of Penetration . shallow fusion between weld metal and base metal. Good Penetration S-0638 Possible Causes Corrective Actions Improper joint preparation. Material too thick. Joint preparation and design must provide access to bottom of groove while main...