Lesson 1Process selection rationale for root, hot, and fill passes on 6 mm 304L butt joint (e.g., GTAW root + pulsed GMAW fill)Gives a clear way to pick processes for root, hot, and fill passes on 6 mm 304L butt joints, comparing GTAW, regular GMAW, pulsed GMAW for reach, output, bending, and code or customer 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 gas choices for GTAW and GMAW on 304L, pure argon, argon-helium mixes, nitrogen-free backing gases, with suggested flow rates, nozzle sizes, techniques to stop holes and 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 common wire and electrode sizes for 6 mm 304L roots and fills, linking to feed speed, current, deposit rate, tuning settings for penetration, bead shape, position welding needs.
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 ranges for GTAW, GMAW, SMAW on 6 mm 304L plate, balancing penetration, bead shape, bending control, avoiding no fusion 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-casesDescribes when SMAW, pulsed GTAW, pulsed GMAW work well on 304L, for site work, awkward positions, thin-to-thick joins, with 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 methods, how electrode shape, current type, shielding gas control arc focus, 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 joint positioning, rotators for round welds on about 1 m diameter shells, setup, alignment, speed control, safety for steady heat input, bead shape around 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 basics for stainless, short-circuit, globular, spray, pulsed transfer modes, configuring power source, feeder, gun, inductance for steady arcs, low spatter on 304L joints.
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 filler types for 304L stainless, comparing ER308L, ER309L, ER316L, choosing wire/electrode sizes matching joint design, position, strength, rust performance 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 how power source type, polarity affect arc steadiness, penetration, bead shape in GTAW, GMAW on stainless, constant current vs voltage, correct connections per process.
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 systems, trailing shields, backing strips, heat sinks improving shielding, reducing bending, protecting root quality on 6 mm 304L plate, shell joints.
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
