Lesson 1Process selection rationale for root, hot, and fill passes on 6 mm 304L butt joint (e.g., GTAW root + pulsed GMAW fill)Gives step-by-step way to pick processes for root, hot, fill on 6 mm 304L butts, comparing GTAW, standard GMAW, pulsed GMAW on access, speed, distortion, code needs.
Evaluating joint access and position limitsGTAW roots for control and low defect ratesPulsed GMAW for fill and cap productivityBalancing heat input and distortion controlExample procedures for 6 mm butt jointsLesson 2Shielding gas selection and flow rates: pure argon, argon-helium blends, and backing gas needsCovers shielding and backing gases for GTAW, GMAW on 304L, pure argon, argon-helium mixes, nitrogen-free backing, flow rates, nozzles, tips to avoid porosity, oxidation.
Pure argon for GTAW and GMAW on 304LArgon–helium blends for higher heat inputBacking gas types and oxygen limitsTypical flow rates and nozzle selectionPreventing porosity and sugaring issuesLesson 3Wire and electrode diameters and feed settings for root and fill passes (typical sizes for 6 mm thickness)Specifies usual wire, electrode sizes for 6 mm 304L root, fill, tied to feed speed, amps, deposition, tuning for penetration, bead shape, position work.
Typical GTAW tungsten diameters for 6 mmSolid wire diameters for GMAW on 304LSMAW electrode sizes for plate and pipeWire feed speed versus amperage relationAdjusting size and feed for position weldingLesson 4Recommended parameter ranges: current type, amperage ranges for 6 mm, voltage, travel speed approximationsSets practical current, voltage, travel speed for GTAW, GMAW, SMAW on 6 mm 304L, balancing penetration, bead, distortion, avoiding fusion lack or burn-through.
Current type and polarity choice by processTypical amperage ranges for 6 mm plateVoltage windows for short, spray, and pulseTravel speed targets for root and fill passesAdjusting parameters for position and fit-upLesson 5SMAW (stick) and pulsed TIG/GMAW when applicable: electrode choices and use-casesCovers when SMAW, pulsed GTAW, pulsed GMAW suit 304L, field jobs, out-of-position, thin-thick joins, electrode types, sizes, operating ranges.
SMAW electrodes for 304L stainless jointsPulsed GTAW for thin or heat‑sensitive areasPulsed GMAW for out‑of‑position weldsElectrode and wire diameter selectionTypical parameter windows for each optionLesson 6GTAW (TIG) fundamentals: AC vs DC, electrode types (thoriated/lanthanated), electrode preparation and sharpeningReviews GTAW basics for stainless, AC vs DC, tungsten types, tip prep, how electrode shape, current, gas control arc, penetration, bead finish.
When to use DCEN versus AC on stainlessThoriated versus lanthanated tungsten typesGrinding and tapering tungsten electrodesAvoiding contamination and arc wanderCurrent limits by tungsten size and tip formLesson 7Joint position and rotator use for circumferential welds on ~1 m diameter shellsCovers positioning, rotators for circumferential welds on about 1 m shells, setup, alignment, speed, safety for steady heat, bead profile round the circle.
Setting up shells on rollers or rotatorsAligning joint gaps and high‑low mismatchSynchronizing rotation and travel speedCable management and operator safetyMaintaining consistent bead profileLesson 8GMAW (MIG/MAG) fundamentals: transfer modes (short-circuit, globular, spray, pulsed), equipment setupIntroduces GMAW for stainless, short-circuit, globular, spray, pulsed modes, setting power source, feeder, gun, inductance for stable arc, low spatter on 304L.
Short‑circuit transfer on thin or root passesGlobular transfer limits and drawbacksSpray transfer for flat and horizontal weldsPulsed spray for positional stainless workKey GMAW equipment setup parametersLesson 9Filler metal classifications for 304L stainless: ER308L/ER309L/ER316L selection rules and wire/electrode diametersExplains AWS fillers for 304L, ER308L, ER309L, ER316L comparison, choosing wire, electrode sizes for joint, position, mechanical, corrosion needs.
Overview of AWS stainless filler designationsWhen to select ER308L for 304L base metalUsing ER309L for dissimilar or butteringUsing ER316L for enhanced corrosion serviceDiameter selection for root and fill passesLesson 10Polarity and power source considerations for GTAW and GMAW with stainlessDetails power source, polarity effects on arc stability, penetration, bead in GTAW, GMAW on stainless, constant current vs voltage, terminal links.
CC versus CV power source characteristicsGTAW polarity and terminal connectionsGMAW polarity for solid and metal‑cored wireEffects of polarity on penetration patternTroubleshooting arc instability issuesLesson 11Equipment accessories: gas lenses, purging systems, trailing shields, backing strips, and heat sinksExplains accessories like gas lenses, purging, trailing shields, backing strips, heat sinks improving shielding, less distortion, root protection for 6 mm 304L, shell joins.
Gas lenses for laminar shielding coverageInternal purging dams and purge monitorsTrailing shields for long stainless beadsBacking bars, strips, and ceramic tilesHeat sinks for distortion and burn‑through
