title = "TIG/GTAW Welding: Technique and Applications"

content = """
Gas Tungsten Arc Welding (GTAW), universally called TIG (Tungsten Inert Gas) welding, is used at Ridgecrest Metalworks for applications requiring the highest weld quality, precise heat control, clean appearance, and compatibility with a wide range of metals including stainless steel, aluminum, titanium, copper alloys, and nickel alloys.

The GTAW process uses a non-consumable tungsten electrode to establish the arc. The welder holds the torch in one hand and manually feeds filler rod into the leading edge of the weld pool with the other. A foot pedal or torch-mounted amperage control allows the operator to modulate heat continuously during welding. Shielding gas (argon or helium, or mixtures) flows through the torch cup and protects the tungsten electrode, the arc, and the hot weld pool from atmospheric contamination.

Tungsten electrode selection and preparation are important. For AC welding of aluminum, a pure tungsten or zirconiated tungsten electrode is balled at the tip by the arc during welding—this is normal. For DCEN (direct current electrode negative) welding of steel, stainless, and titanium, a thoriated (2% ThO2) or ceriated (2% CeO2) tungsten is prepared with a tapered point ground in the direction of the electrode axis. Point geometry affects arc stability and bead width.

AC TIG is used for aluminum because the electrode positive half-cycle provides a cathodic cleaning action that breaks up the aluminum oxide layer, enabling fusion. DCEN is used for all other metals; it concentrates heat in the base metal (negative electrode) rather than the tungsten (positive electrode).

Filler rod selection must match the base metal and application. For 304 stainless, ER308L filler is standard. For 316L, ER316L is used. For mild steel, ER70S-2 or ER70S-6 is common. For aluminum 6061, ER4043 or ER5356 is used. Using wrong filler can produce a weld that looks perfect but has poor mechanical properties or cracking susceptibility.

TIG weld quality requires extremely clean base metal (wiped with acetone or cleaned with stainless wire brush) and clean filler rod. Contaminated welds show porosity, black soot, and oxidation. Tungsten contamination (touching the weld pool) produces a hard tungsten inclusion in the weld that must be ground out.
"""

version = "0.0.1"
