Welding Defect Analysis

Learn how to evaluate parts for welding defects associated with resistance, MIG, and projecting operations. Students will learn the troubleshooting skills necessary to address weld quality issues and suggest potential counter measures in the automotive manufacturing environment. 

Course Outline  

1.0 How a Weld is Made 
1.1 Resistance Spot Welding
1.2 Characteristics of the Weld Nugget 
1.3 Making a Spot Weld  
- Single Spot 
- Double Spot 
- Projection Weld 
1.4 Relationship of the Welding Variables 
- Single Spot 
- Double Spot 
- Projection Weld 
1.5 The Elementary Welding System 

2.0 Weld Schedules Metals and Other Variables 
2.1 Resistance Spot Welding 
2.2 Basic Welding Circuit
- Producing Weld Heat 
- Spot and Projection Welding Components 
- Electrodes and Other Current-Carrying Members 
- Pressure System 
2.3 Weld Sequence 
- Squeeze 
- Weld Time 
- Hold 
2.4 Welding Variables (Single, Double, Projection Welds) 
- Weld Circuit Effects on Weld Heat 
- Current and Voltage 
- Electrode Face Area
- Time 
- Weld Loop Impedance 
- Electrode Force  

3.0 Protective Coatings and Contaminants 
3.1 Galvanized Steel 
- Hot Dipped 
- Electroplate 
3.2 Contaminants on the Metal 
- Drawing Compound 
- Dirt and Scale 
- Oils 
- Rust 
- Sealer 
3.3 Composition of Metal (Metallurgy) 
- Weld Heat Balance 
- Equal Thickness 
- Unequal Thickness 

4.0 Weld Schedules 
4.1 Weld Tables 
- Three-ply Weld Schedule 

5.0 Weld Quality Defects (Spot and Projection Welds) 
5.1 Surface Defects 
- Indentation 
- Surface Deformation Surface Burning 
- Surface Expulsion (Whiskers) 
- Cracks 
- Blow Holes 
5.2 Weld Nugget Defects 
- Undersize Nugget 
- Low Penetration 
- Porosity 
- Expulsion 
- Misshapen Weld Nugget 
- Poor Part Fit-up 
- Fixture Related Issues 
- Poor Electrode Alignment  
5.3 Corrective Action for Eliminating Spot Weld Defects 
- Correction of Surface Defects 
- Correction of Weld Nugget Defects 

6.0 General Maintenance 
6.1 Weld Schedules 
6.2 Caps  
6.3 Water Tubes 
6.4 Contaminants on the Metal 
6.5 Guns 
6.6 Cables 
6.7 Fixtures 

7.0 Troubleshooting 
7.1 Generic Weld Inspection Process 
- Destructive Testing 
- Non-Destructive Testing (W&A) 
7.2 Troubleshooting Flow Chart 
7.3 Welding Sequence Consequences 
- Spot and Projection Welding 
- MIG Welding 
- Laser Welding 

8.0 Exercises 
Interactive hands-on exercises designed to introduce the students to the troubleshooting process: 
Exercise 1: Identifying Common Spot Weld defects 
Exercise 2: Evaluating Spot Weld Defects on Assemblies 
Exercise 3: Identifying Common Projection Weld Defects 
Exercise 4: Identifying Common MIG Weld Defects 
Exercise 5: Evaluating MIG Weld Defects on Assemblies 
Exercise 6: Evaluating Projection Weld Defects on Assemblies 
Exercise 7: Rework Methods for Weld Defects

Who should attend?
All types of Engineers, Product Designers, Tool and Die Makers, Welding Maintenance, and Launch Personnel.