B-9

OPERATION

B-9

 

 

 

STT WELDING

The pictures illustrate the wave shape of current for the process. They are not drawn to scale, and are intend- ed only for the purpose of showing how the variables effect the waveform.

Trim in the STT mode adjusts the tail out and back- ground portion of the waveform. For open root processes, the tail out is fixed, and the trim affects only the background level. Trim values greater than 1.0 add more energy to the weld and make the weld puddle hotter; trim values less than 1.0 reduce energy to weld A nominal value of 1.0 will work for most applications. (See Figure A.7)

For most programs, peak current is adjusted by arc control, also referred to as wave control. A wave con- trol value of +10.0 maximizes the peak current, while a wave control of -10.0 minimizes peak current. In gen- eral, the peak current is proportional to the arc length. (See Figure A.8)

NOTE: The ranges on Wave Control and Trim are dependent on the weld programs. The values shown are typical ranges.

FIGURE A.7

Current

Time

Current

Time

Trim 1.50

Trim 1.00

Trim 0.50

FIGURE A.8

Wave Control +10.0

Wave Control 0.0

Wave Control -10.0

POWER WAVE 455M/STT (CE)

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Image 29
Lincoln Electric IM924 manual STT Welding, Figure A.7