LECTURE PRESENTATION

Reading Assignment

• 30.1 Introduction to Consolidation Processes
• 30.2 Classification of Welding and Thermal Cutting Processes
• 30.3 Some Common Concerns
• 30.4 Types of Fusion Welds and Types of Joints
• 30.5 Design Considerations
• 30.6 Heat Effects
• 30.7 Weldability or Joinability
• AWS Certified Welding Engineer

Additional Reading

• Welding Principles and Applications, 4th ed., 1999, Larry Jeffus
• AWS/ANSI Z49.1 – Safety in Cutting, Welding, and Allied Processes (pdf download)
• Study Guide – Welding
• AWS D1.1/D1.1 M2006 Structural Welding Code – Steel (in library)
• B5.16:2006, Specification for the Qualification of Welding Engineers (see AWS)

Outline

Thermal Joining

• Welding
• Brazing
• Soldering

Welding

Major Classifications

• Solid State Welding
• Fusion Welding

AWS Classifications

• Oxyfuel Gas Welding (OFW)
  • Oxyacetylene Gas Welding (OAW)
  • Pressure Gas Welding (PGW)
• Arc Welding (AW)
  • Shielded Metal Arc Welding (SMAW)
  • Gas Metal Arc Welding (GMAW)
  • Gas Tungsten Arc Welding (GTAW)
  • Flux Cored Arc Welding (FCAW)
  • Submerged Arc Welding (SAW)
  • Plasma Arc Welding (PAW)
  • Stud Welding (SW)
• Resistance Welding (RW)
  • Resistance Spot Welding (RSW)
  • Projection Welding (RPW)
• Solid State Welding (SSW)
  • Forge Welding (FOW)
  • Cold Welding (CW)
  • Friction Welding (FRW)
  • Ultrasonic Welding (USW)
  • Explosion Welding (EXW)
  • Roll Welding (ROW)
• Unique Processes
  • Thermit Welding (TW)
  • Laser-Beam Welding (LBW)
  • Electroslag Welding (ESW)
  • Flash Welding (FW)
  • Induction Welding (IW)
  • Electron-Beam Welding (EBW)

Safety Considerations (General)

• Electrical Shock
• Fumes and Gases
• UV Radiation (see ANSI Z49.1 & Z87.1)
• Fire & Explosion Hazards
• Flying Metal (from welding, chipping, grinding, cooling, etc. )
• Gas buildup
• Hot Parts & Electrodes
• Magnetic Fields
• Noise
• Cylinder safety

Basic Weld Positions and Joints

• Weld Nomenclature
  • Root
  • Leg
  • Face
  • Throat, Effective Throat
• Weld Types
  • Fillet
  • Plug
  • Stud
  • Groove
    • V-groove
    • J-groove
    • U groove
  • Intermittent
  • Surfacing
• Joint Types
  • Positions
  • Weld Joint Types
    • Lap
    • Corner
    • Butt
    • T-Joint
    • Edge Joint
• Material Considerations
  • Base Metals must be compatible
    • With each other
    • With filler metal
    • With process
  • Base metal must be clean
  • Base metal must be ground appropriately
• Heat Effects
  • Thermal expansion
  • Distortion and cracking
  • Weld pool is a casting
  • HAZ surrounds weld area
  • Post-Weld heat treatment
  • Techniques to minimize distortion
    • Intermittent welds
    • Restraints

Weld Defects

• Porosity
• Cracks
• Cavities
• Inclusions
• Unacceptable weld shape
• Incomplete fusion
• Incomplete penetration
• Arc Strikes
• Spatter
• Metallurgical changes
• Excessive Distortion

Design Considerations

• Monolithic Structure
• Crack propagation
• Vibration and stress transfer
• Rigidity

Inspection Techniques

Destructive Tests

• Bend Test (guided/free)
  • Root Bend
  • Face Bend
  • Side Bend
• Tensile Test
• Elongation
• Hardness
• Impact Values
• Macroscopic and Microscopic Testing

Nondestructive tests

• Magnetic Particle Inspection
  • Dry Method
  • Wet Method
• Dye Penetrant
• Radiographic Inspection
• Ultrasonic Inspection
• Electromagnetic Testing (Eddy Current)
• Proof Testing
• Leak Testing

Critical Variables

• Electrical Variables
• Consumables
• Dimensions
• Heat Input

Weld Symbols

AWS A2.4:2007

• Weld All Around
• Field Weld
• Weld Type
• Arrow Side/Other Side
• Increments/Staggering
• Process Designation