Gas Tungsten Arc Welding
Gas tungsten arc (TIG) welding at a fabrication shop in Pasadena, on the Houston Ship Channel: power sources, polarity and AC balance, torches and gas lenses, tungsten types and grinding (and the move away from thoriated tungsten), shielding gas and back purging, filler metals and dabbing, GTAW on carbon steel, stainless steel and aluminum, pulsed GTAW, defects and inspection, and a capstone that qualifies for and welds a purged 316L chemical injection line built to ASME B31.3 and repairs a cracked aluminum water tank.
WLD-310 12 lessons · 3 h 14 min ▶ Video lessons coming soon
Offered by HSM University · Welding
This is the American version of this course. See the Canadian version.
What you'll learn
- Explain how GTAW works, what the welder controls, its strengths and limits, its hazards, and calculate GTAW arc energy and heat input with and without a thermal efficiency factor
- Select and set up GTAW power sources, polarity, AC balance, AC frequency and the weld sequence settings from pre-flow to post-flow for steel, stainless and aluminum
- Assemble GTAW torches with matched collets, collet bodies or gas lenses, cups and stickout, set gas flow for the cup, and find and correct gas leaks
- Identify tungsten electrode classifications, explain the hazards of thoriated tungsten and its alternatives, choose diameters for the current, and grind and maintain tungsten tips
- Choose shielding gases, maintain gas coverage at the torch, and set up and verify back purges for stainless steel with oxygen measurement and safe venting
- Select GTAW filler metals for carbon steel, stainless steel and aluminum, keep filler clean, add filler by dabbing and other techniques, and estimate filler consumption
- Weld carbon steel sheet, light plate and small-bore socket joints with GTAW, controlling cleaning, fit-up, distortion and production time
- Weld austenitic stainless steel with GTAW while controlling sensitization, ferrite, heat tint, interpass temperature, heat input and surface contamination
- Weld aluminum with AC GTAW by cleaning correctly, managing heat as the part warms, filling craters, and recognizing the effects of welding on aluminum strength
- Use pulsed GTAW, walking the cup, thin-to-thick technique, tacking and root techniques for specific problems, and calculate average current for pulse settings
- Identify GTAW defects and their causes, apply visual and other examinations including tint and ferrite checks, and remove and repair defects within repair limits
- Complete production GTAW on a qualified stainless process line and a planned aluminum crack repair, from qualification and weld map to inspection and records
Course content
12 lessons · 3 h 14 min total · final exam
- 1 How GTAW works 17 min · quiz
- 2 GTAW power sources, polarity and AC balance 17 min · quiz
- 3 Torches, cups, gas lenses and accessories 16 min · quiz
- 4 Tungsten electrodes: types, sizes and preparation 16 min · quiz
- 5 Shielding gas, purging and gas coverage 16 min · quiz
- 6 Filler metals and adding filler 16 min · quiz
- 7 GTAW on carbon steel 16 min · quiz
- 8 GTAW on stainless steel 16 min · quiz
- 9 GTAW on aluminum 16 min · quiz
- 10 Pulsed GTAW and other techniques 16 min · quiz
- 11 GTAW defects and quality 16 min · quiz
- 12 Capstone: a stainless process line and an aluminum tank repair 16 min · quiz
- E Final exam 20 questions
Requirements
Recommended background. You can start any course at any time.
Description
Gas tungsten arc (TIG) welding at a fabrication shop in Pasadena, on the Houston Ship Channel: power sources, polarity and AC balance, torches and gas lenses, tungsten types and grinding (and the move away from thoriated tungsten), shielding gas and back purging, filler metals and dabbing, GTAW on carbon steel, stainless steel and aluminum, pulsed GTAW, defects and inspection, and a capstone that qualifies for and welds a purged 316L chemical injection line built to ASME B31.3 and repairs a cracked aluminum water tank.