| 1.0 |
How a Weld is Made |
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1.1 Resistance
Spot Welding |
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1.2 Characteristics of the Weld Nugget |
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1.2.1 Making a Spot Weld |
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· Single Spot |
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· Double Spot |
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· Projection Weld |
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1.3 Relationship of the Welding Variables |
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· Single Spot |
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· Double Spot |
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· Projection Weld |
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1.4 The Elementary Welding System |
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| 2.0 |
Weld Schedules, Metals and Other Variables |
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2.1 Resistance Spot Welding |
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2.2 Basic Welding Circuit |
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· Producing Weld Heat |
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· Spot and Projection Welding Components |
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· Electrodes and Other Current-Carrying Members |
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· Pressure System |
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2.3 Weld Sequence |
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· Squeeze |
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· Weld Time |
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· Hold |
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2.4 Welding Variables (Single, Double, Projection Welds) |
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· Weld Circuit Effects on Weld Heat |
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· Current and Voltage |
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· Electrode Face Area |
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· Time |
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· Weld Loop Impedance |
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· Electrode Force |
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| 3.0 |
Protective Coatings and Contaminants |
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3.1 Galvanized Steel |
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· Hot Dipped |
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· Electroplate |
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3.2 Contaminants on the Metal |
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· Drawing Compound |
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· Dirt and Scale |
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· Oils |
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· Rust |
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· Sealer |
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3.3 Composition of Metal (Metallurgy) |
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· Weld Heat Balance |
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· Equal Thickness |
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· Unequal Thickness |
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| 4.0 |
Weld Schedules |
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4.1 Weld Tables |
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· Three-ply Weld Schedule |
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| 5.0 |
Weld Quality Defects (Spot and Projection Welds) |
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5.1 Surface Defects |
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· Indentation |
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· Surface Deformation Surface Burning |
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· Surface Expulsion (Wiskers) |
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· Cracks |
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· Blow Holes |
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5.2 Weld Nugget Defects |
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· Undersize Nugget |
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· Low Penetration |
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· Porosity |
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· Expulsion |
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· Misshaped Weld Nugget |
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· Poor Part Fit-up |
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· Fixture Related Issues |
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· Poor Electrode Alignment |
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5.3 Corrective Action for Eliminating Spot Weld Defects |
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· Correction of Surface Defects |
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· Correction of Weld Nugget Defects |
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| 6.0 |
General Maintenance |
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6.1 Weld Schedules |
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6.2 Caps |
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6.3 Water Tubes |
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3.2 Contaminants on the Metal |
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6.4 Guns |
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6.5 Cables |
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6.6 Fixtures |
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| 7.0 |
Troubleshooting |
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7.1 Generic Weld Inspection Process |
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· Destructive
Testing |
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· Non-Desctructive
Testing (W & A) |
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7.2 Troubleshooting Flow Chart |
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7.3 Welding Sequence Consequences |
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· Spot
and Projection Welding |
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· MIG Welding |
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· Laser Welding |
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| 8.0 |
Exercises |
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| Interactive hands on exercises designed to introduce the students
to the troubleshooting process: |
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Exercise 1: Identifying Common Spot
Weld defects |
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Exercise 2: Evaluating Spot Weld Defects on Assemblies |
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Exercise 3: Identifying Common Projection Weld Defects |
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Exercise 4: Identfying Common MIG Weld Defects |
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Exercise 5: Evalauting MIG Weld Defects on Assemblies |
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Exercise 6: Evaluating Projection Weld Defects on Assemblies |
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Exercise 7: Rework Methods for Weld Defects |
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