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TIG Welding Pulse Parameters - Advanced Control | Knowledge Center

Pulse Parameters in TIG Welding

Advanced Control for Precision Welding

Pulse TIG welding offers superior control over heat input, penetration, and weld appearance by alternating between high and low current levels. Understanding these parameters allows welders to achieve optimal results across various materials and thicknesses.

Key Benefits of Pulse TIG Welding

  • Reduced heat input minimizes distortion on thin materials
  • Improved control over weld puddle for better precision
  • Enhanced penetration profile with narrower heat-affected zone
  • Better arc stability, especially on challenging materials
  • Reduced tungsten erosion for longer electrode life
  • Improved aesthetic appearance with consistent "stacked coins" look

Basic Principles

  • Alternates between peak and base current
  • Controls heat input precisely
  • Creates controlled cooling cycles

Applications

  • Thin materials (0.5-3mm)
  • Heat-sensitive alloys
  • Out-of-position welding

Materials

  • Stainless steel
  • Aluminum
  • Exotic alloys

Peak Current

Maximum Current in Pulse Cycle

Function

  • Provides penetration
  • Creates material fusion
  • Forms weld puddle

Control

  • Typically 150-300% of base current
  • Adjustable independently
  • Precise heat control

Applications

  • Deep penetration
  • Thick materials
  • Root passes

Base Current

Minimum Current in Pulse Cycle

Function

  • Maintains arc stability
  • Allows material cooling
  • Keeps arc alive between peaks

Control

  • Typically 10-50% of peak current
  • Lower limit: Arc stability threshold
  • Upper limit: Desired cooling effect

Benefits

  • Reduced heat input
  • Better control on thin materials
  • Minimized distortion

Pulse Frequency

Pulse Rate (Hz)

Frequency Range Characteristics Applications
Low Frequency
(0.5-5 Hz)		 Visible pulses, distinct cooling cycles Manual filler rod addition, thin materials, visible "stacked coins" appearance
Medium Frequency
(5-50 Hz)		 Less visible pulses, balanced heat control General purpose welding, moderate thickness materials
High Frequency
(50-500 Hz)		 Smooth arc appearance, focused arc column Automated welding, deeper penetration, narrower weld profile

Technical Specifications

  • Range: Typically 0.5 to 500 Hz depending on equipment
  • Higher frequencies create a "stiffer" arc with improved directional control
  • Lower frequencies allow better puddle control and cooling between pulses
  • Arc sound changes with frequency - useful auditory feedback for experienced welders

Pulse Width

Duration of Peak Current

Control Function

  • Percentage of total pulse cycle at peak current
  • Range: Typically 10-90% of cycle time
  • Also called "duty cycle" in some machines

Higher Width Effects

  • More heat input
  • Deeper penetration
  • Wider weld bead

Lower Width Effects

  • Less heat input
  • Better for thin materials
  • Narrower weld profile

Clear Width

Duration of Base Current

Control Function

  • Percentage of cycle at base current
  • Cooling time between peak pulses
  • Inverse relationship with pulse width

Applications

  • Heat-sensitive materials
  • Distortion control
  • Thin-section welding

Balance Considerations

  • Pulse Width + Clear Width = 100%
  • 50/50 for balanced operation
  • 30/70 for minimal heat input

Practical Tips for Pulse Parameter Selection

Thin Materials

  • Lower peak current (30-70A)
  • Lower pulse width (20-40%)
  • Higher frequency (5-10 Hz)

Medium Materials

  • Moderate peak current (70-150A)
  • Balanced pulse width (40-60%)
  • Medium frequency (3-7 Hz)

Thick Materials

  • Higher peak current (150A+)
  • Higher pulse width (60-80%)
  • Lower frequency (1-3 Hz)