Lecture Notes on Classification of Welding and Joints

Recap of Previous Class

• Introduction to welding
• Classification started:
  • Mechanical bonding
  • Atomic bonding (Welding falls under this category)

Classification of Welding

• Categories based on different aspects:
  1. Source of heat
  2. Application of pressure
  3. Phases of base and filler material
  4. Composition of the joint
  5. Position of the electrode
  6. Mechanism of welding

Source of Heat

• Discussed in previous lecture

Application of Pressure

• Categories:
  • Pressure Welding:
    • Pieces heated to a plastic state and joined using external pressure
    • Also known as plastic welding
  • Non-Pressure Welding (Fusion Welding):
    • Material heated to a molten state and allowed to solidify
    • No external pressure applied
    • Involves inter-material fusion

Examples of Welding Techniques:

• Fusion Welding (Non-Pressure):
  • Arc welding
  • Gas welding
  • Electron beam welding
• Pressure Welding:
  • Solid state welding
    • Resistance Welding
    • Friction Welding
    • Ultrasonic Welding
    • Cold Pressure Welding
    • Induction Welding
    • Spot, Seam, Projection, Butt, and Flash Resistance Welding

Phases of Base and Filler Material

• Categories:
  1. Liquid Phase Welding
  2. Solid Phase Welding
  3. Solid-Liquid Phase Welding

Details:

• Liquid State Welding:
  • All fusion welding processes
• Solid State Welding:
  • Friction, Ultrasonic, and others
• Solid Liquid State Welding:
  • Soldering and Brazing

Composition of Joint

• Categories:
  1. Autogenous (no filler material used)
  2. Homogeneous (same composition of filler and base material)
  3. Heterogeneous (different compositions)

Position of Welding

• Categories:
  1. Down Hand or Flat Welding
  2. Horizontal Welding
  3. Vertical Down Welding
  4. Vertical Up Welding
  5. Overhead Welding

Mechanism of Welding

• Categories:
  1. Manual Welding
  2. Semi-Automatic Welding
  3. Fully Automatic Welding

Key Parameters:

• Feeding of Electrode: Continuous movement of filler material
• Welding Speed: Speed of welding per second or hour

Types of Weld Joints

• Types:
  1. Butt Joint
  2. T Joint
  3. Lap Joint
  4. Corner Joint
  5. Edge Joint

Details of Each Joint:

Butt Joint:

• Formed by laying pieces side by side
• Different edge preparations lead to types such as:
  • Square Groove Butt Joint
  • Bevel Groove Butt Joint
  • V Groove Butt Joint
  • J Groove Butt Joint
  • U Groove Butt Joint

T Joint:

• Formed by placing one piece vertically on another
• Commonly uses fillet welding
• Types of T Joints:
  • V Weld T Joint
  • J Group T Joint

Lap Joint:

• Formed by overlapping two pieces
• Types:
  • Fillet Welded Lap Joint
  • Plug Welded Lap Joint
  • Slot Welded Lap Joint

Corner Joint:

• Formed by placing one piece to create a corner
• Types:
  • Flush Corner Joint
  • Half Flush Corner Joint
  • Fully Open Corner Joint

Edge Joint:

• Formed by bringing two edges together
• Less commonly used
• Types:
  • Square Groove Edge Joint
  • V Groove Edge Joint
  • J Groove Edge Joint
  • U Groove Edge Joint

Edge Preparation

• Importance:
  • Affects strength and accessibility of filler material
• Types of Edge Preparation:
  1. Square Edge
  2. Bevel Edge
  3. J Groove
  4. U Groove

Shape and Name of Different Welds

• Shapes:
  • Butt, Flat, Compound, and various types for joints
• Naming Conventions:
  • Butt Welded Butt Joint
  • Fillet Welded T Joint
  • Compound Welded Lap Joint

Conclusion

• Different parts of a joint include:
  1. Joint Root
  2. Groove Face
  3. Root Face
  4. Root Edge
  5. Root Opening Angle
  6. Groove Angle
  7. Groove Radius

Next Steps

• Detailed discussion on parts of the welded joint in the next lecture.