A high frequency generator is employed for arc starting and stabilization. Pure or zirconiated tungsten electrodes are used for AC welding. Tungsten electrodes should be prepared with a hemispherical shaped tip. The parameters for manual GTAW are dependent upon plate thickness, weld position and joint design. The following settings should be helpful in establishing a procedure.
Settings are for the flat position.
Filler metal transfer is in the spray mode. Clean The Base Metal Cleaning should be done just prior to welding to prevent the formation of oxides. The base metal surface must be free of grease, oil, paint, dirt, etc A clean surface will provide a smoother, stronger joint. Gloves should be worn to prevent hand oil or dirt from getting on the joining surface. If Applicable Preheat is not required for most 300 austenitic grade stainless steels.