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 choose methods for root, hot, fill on 6 mm 304L butts, comparing GTAW, regular GMAW, pulsed GMAW for reach, speed, warp, 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 shield and back gas for GTAW GMAW on 304L, pure argon, argon-helium mixes, nitrogen-free back gas, flow rates, nozzle sizes, tricks to stop holes and rust.
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)Sets common wire electrode sizes for 6 mm 304L root fill, links to feed speed, amps, deposit rate, tuning for depth, 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 approximationsGives real current, voltage, speed ranges for GTAW GMAW SMAW on 6 mm 304L, balance depth, bead, warp control, avoid no fusion or burn.
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-casesSays when SMAW, pulsed GTAW, pulsed GMAW good for 304L, field jobs, odd positions, thin-thick joins, electrode types, sizes, 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 DC compare, tungsten types, tip prep, how shape, current, gas control arc, depth, 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 place, rotators for round welds on 1m shells, setup, align, speed, safety for steady heat, bead all round.
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, set power, feeder, gun, inductance for steady arc, low splatter 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 compare, pick wire electrode sizes for joint, position, strength, rust 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 type, polarity on arc steady, depth, bead in GTAW GMAW stainless, constant current vs voltage, right connections.
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 add-ons like gas lenses, purge systems, trailing shields, back strips, heat sinks improve shield, cut warp, protect root on 6 mm 304L plate shells.
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
