WPS QW-409 Electrical Characteristics

ASME Section IX WPS : QW-409 Electrical Characteristics Example

ASME Section IX Welding Variables for a WPS : QW-409 Electrical Characteristics

• QW-409.1

  • An increase in heat input

  • For arc welding the heat input increase shall be determined by the following

    • Non-waveform controlled

      • a : Heat input formula

      • b : Volume of weld metal

      • c : Instantaneous Energy or Power

    • Waveform controlled:

      • b : Volume of weld metal

      • c : Instantaneous Energy or Power

• QW-409.3

  • The addition or deletion of pulsing current to DC power source

• QW-409.4

  • A change from AC to DC or vice versa

  • A change from DCEN to DCEP or vice versa

    • DCEN : Direct Current Electrode Negative (Straight Polarity)

    • DCEP : Direct Current Electrode Positive (Reverse Polarity)

• QW-409.8

  • A change in the range of amperage for SMAW or GTAW

  • A change in the range of voltage for waveform controlled welding

  • Wire Feed Speed (WFS) may be used as an alternative to amperage (See Appendix H)

• QW-409.12

  • A change in the type or size of tungsten electrode

• QW-409.30

  • A change from AC to DC or vice versa

  • A change from DCEN to DCEP or vice versa

  • This variable does not apply for

    • P-No. 8 (austenitic stainless steel alloy)

    • P-No. 21 thru 26 (aluminum alloys)

    • P-No. 41 thru 49 (nickel alloys)

• QW-409.32

  • At least one of the following transfer modes shall be specified

    • short circuiting

    • globular

    • spray

    • pulsed spray

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Essential Variable: Variables for which a change is considered to affect the mechanical properties (other than notch toughness) of the joint. Essential variable changes that fall outside their qualified range requires re-qualification. 

Supplementary Essential Variable: Variables for which a change is considered to affect the toughness properties of the joint, heat-affected zone (HAZ), or base material.

Supplementary essential variables become additional essential variables in situations where toughness testing is required. When toughness testing is not required supplementary essential variables are not applicable. 

Non-Essential Variable: Variables for which a change is considered to not affect the mechanical properties of the joint. This allows for editorial revisions to procedures within that permitted by Section IX without the need to requalify the procedure. Nonessential variables shall be documented on the procedure. 

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