Lesson 1Distortion prevention: stitch welds, backstep technique, clamping, low heat input processes, balanced welding sequence, and pre-bending allowanceThis lesson shows stopping warp with stitch welds, backstep, clamps, low-heat methods, balanced order, and pre-bend for join shape and thickness.
Stitch welding and skip sequence planningBackstep technique for shrinkage controlUse of clamps, strongbacks, and fixturesLow heat input processes and passesPre-bending and presetting componentsLesson 2How to prevent hot cracking: filler selection, heat input control, bead sequencing, and use of stabilized/low-carbon fillersThis lesson covers hot crack stops, focusing filler pick, heat control, bead order, and stabilised/low-carbon fillers for freeze mode and stress handling.
Selecting fillers for proper ferrite balanceUsing stabilized and low-carbon filler gradesHeat input limits and interpass temperatureBead sequencing to spread shrinkagePreheat and cooling control for crack resistanceLesson 3Repair/mitigation of distortion: mechanical straightening, local heating, re-welding strategy, acceptance criteria and rework planningThis lesson tackles warp fix and ease, covering straight pull, local heat, smart re-weld, and checks against okay limits to pick fix, redo, or pass.
Measuring distortion and recording baselinesMechanical jacking, pressing, and peeningLocal heat straightening proceduresRe-welding strategies to counter shrinkageAcceptance criteria and repair documentationLesson 4Distortion and warping mechanisms in circumferential shells and brackets: longitudinal and transverse shrinkage, uneven heat distributionThis lesson explores warp and bend in round shells and brackets, focusing length/width shrink, uneven heat, and how join layout/order shape end form.
Longitudinal shrinkage around circumferencesTransverse shrinkage and ovality in shellsBracket-induced local bending and twistHeat input distribution around the jointPredicting distortion from weld size and pathLesson 5Three-pronged prevention methods for fusion/penetration defects: joint prep, parameter control, and techniqueThis lesson details how join prep, setting picks, and skill team up to stop fusion/penetration lacks, stressing steady setups, checks, and procedure records.
Joint design, bevel angle, and root face selectionRoot opening, land, and fit-up tolerancesCurrent, voltage, and travel speed windowsArc length, electrode angle, and manipulationVerification of fusion with visual and NDT checksLesson 6Repair and post-weld remediation of porosity: grinding, re-weld, vacuum backing if needed, and re-inspectionThis lesson details post-weld hole fixes, grinding bad spots, controlled re-weld, optional back/vacuum, and re-check for quality standards.
Identifying porosity extent with NDTGrinding and blending porous regionsRe-welding techniques to avoid repeat poresUse of backing bars or vacuum assistanceFinal inspection, records, and traceabilityLesson 7Hot cracking (solidification cracking/intergranular cracking): root causes in stainless (composition, high sulfur/phosphorus, restraint, heat input)This lesson breaks down hot cracking in stainless welds, tying makeup, dirt levels, join hold, heat to freeze and grain cracks, spotting risks on shop floor.
Solidification cracking in austenitic stainless weldsIntergranular hot cracking along grain boundariesEffects of sulfur and phosphorus impuritiesInfluence of joint restraint and fit-upHeat input, cooling rate, and crack susceptibilityLesson 8Repair strategies for hot cracking: stop-drill and gouge, re-weld with controlled heat input, post-weld cleaning and inspectionThis lesson covers hot crack fixes, stop-drill, gouge/grind, controlled re-weld, full post-clean and check to clear cracks without return.
Crack mapping, marking, and extent assessmentStop-drill techniques to arrest crack growthGouging and grinding to sound metalControlled re-weld with adjusted heat inputPost-weld cleaning, NDT, and documentationLesson 9Lack of fusion and lack of penetration: how they occur on circumferential butt joints and filletsThis lesson clears fusion/penetration lacks in round butt and fillets, linking shape, reach, position, skill to fault spots and check focus.
Root fusion problems in pipe butt weldsSidewall fusion loss in narrow groovesLack of penetration in double-sided weldsFillet weld throat and leg size issuesInspection focus zones on circumferential weldsLesson 10Prevention strategies for porosity: cleaning, gas control, travel technique, purge integrity, and weld pool manipulationThis lesson gives real ways to stop holes, stressing cleans, gas picks/flows, travel skill, purge checks, pool work to let gases out pre-freeze.
Pre-weld cleaning and degreasing proceduresShielding gas composition and flow settingsTorch angle and travel speed for gas escapePurge dams, venting, and leak testingStringer versus weave beads for porosity controlLesson 11Repair methods for lack of fusion/penetration: grind-out, re-weld procedures, preheat/interpass controls, and NDT acceptance limitsThis lesson outlines fusion/penetration fixes, grinding out faults, qual re-weld plans, pre/interpass heat, NDT okay limits pre-final okay.
Locating fusion defects with UT and radiographyGrinding and carbon arc gouging techniquesRe-weld parameters for full penetrationPreheat and interpass temperature controlApplying code NDT acceptance limitsLesson 12Porosity causes in stainless welds: contamination, inadequate shielding, purge failures, and entrapment of gasesThis lesson checks hole forming in stainless welds, linking dirt, poor shield, purge fails, gas traps to hole shapes, and join/position gas paths.
Surface contaminants and moisture sourcesShielding gas flow, turbulence, and draftsBack purging failures in root passesGas entrapment in deep or narrow groovesRecognizing porosity patterns in radiography
