Lesson 1Welding processes for ship repairs: SMAW, GMAW/MIG, FCAW, and submerged arc—process selectionReview main weldin processes used in ship repair, comparin SMAW, GMAW, FCAW, an SAW fi productivity, access, position capability, an quality, an guidin process selection fi typical structural repairs.
SMAW setup and shipyard applicationsGMAW and MIG variants in repairsFCAW self-shielded and gas-shieldedSubmerged arc for panel renewalsProcess selection decision factorsDistortion and heat input controlLesson 2Corrosion repair for bottom shell plating: local renewals, patch plating, and double-skin/trim patch solutionsExplain corrosion damage mechanisms in bottom shell platin an guide selection of local renewals, patches, an double-skin solutions, wid emphasis pon class rules, load paths, drainage, an long-term corrosion protection.
Corrosion types in bottom shell regionsCriteria for local plate renewalsDesign of insert and patch platesDouble-skin and trim patch conceptsScantling checks and class approvalCoating, anodes, and sealing detailsLesson 3Use of advanced materials and consumables: higher-strength steels, corrosion-resistant alloys, and consumable selectionExamine selection an use of higher-strength steels, corrosion-resistant alloys, an weldin consumables, focusin pon matchin strength, toughness, corrosion behavior, an weldability in typical ship repair scenarios.
Grades of higher-strength ship steelsCorrosion-resistant alloys in repairsMatching and overmatching consumablesHydrogen-controlled consumable typesStorage and handling of electrodesDissimilar metal joint strategiesLesson 4Cutting and removal: oxy-fuel, plasma, and CNC/high-precision thermal cuttingExplain safe an accurate removal of damaged structure usin oxy-fuel, plasma, an CNC thermal cuttin, addressin equipment setup, cut quality, heat-affected zones, an minimizin distortion an rework.
Selection of cutting process by taskOxy-fuel cutting setup and safetyManual and mechanized plasma cuttingCNC and template-guided cuttingControl of HAZ and edge qualityDistortion control during removalLesson 5Prefabrication and modular panel replacement: templates, edge preparation and tolerancesCover plannin an fabrication of modular replacement panels, includin measurement methods, template creation, edge preparation, tolerances, an alignment fi minimize onboard fittin time an weldin distortion.
Damage survey and panel mappingTemplate methods and digital scanningShop fabrication and fit-up checksEdge preparation and root gapsDimensional tolerances and fairnessLifting, handling, and positioningLesson 6Weld quality control: welders qualification, NDT acceptance criteria, and repair limitsCover weld quality control in ship repair, includin welder qualification, WPS compliance, NDT methods, acceptance criteria, an repair limits, ensurin structural integrity an regulatory conformity.
Welder qualification and continuityVisual inspection and weld gaugesUltrasonic and radiographic testingMagnetic particle and dye penetrantAcceptance criteria and defect limitsRepair welding and reinspection stepsLesson 7Damage assessment to repair decision framework and scope definitionProvide a structured framework from initial damage assessment to repair decision an scope definition, integratin class requirements, risk, cost, downtime, an long-term structural performance.
Initial inspection and data collectionUse of NDT and thickness measurementsResidual strength and buckling checksTemporary versus permanent repairsRepair scope and work package definitionCoordination with class and ownerLesson 8Welding procedure specifications (WPS), preheat/postheat, PWHT considerations for common ship steelsDescribe development an qualification of WPS fi ship steels, includin preheat an interpass control, postheat, an PWHT decisions, wid attention to hydrogen crackin, hardness limits, an class documentation.
Essential WPS variables and rangesPreheat and interpass temperature controlPostheat for hydrogen diffusionPWHT need, methods, and limitsHardness and microstructure controlWPS qualification and recordsLesson 9Joint design improvements to reduce stress concentrations and extend fatigue lifeFocus pon joint design improvements fi reduce stress concentrations an extend fatigue life, coverin geometry changes, soft transitions, backin details, weld profiles, an alignment fi optimize load transfer.
Assessment of existing joint detailsNotch effects and stress raisersSmooth transitions and tapersBacking bars and run-on tabsOptimized weld profiles and toesAlignment and fit-up tolerancesLesson 10Fatigue crack repair strategies: stop-holes, full-penetration welds, splice plates, doublers and redesign of detailsDetail fatigue crack mechanisms an repair options, includin stop-holes, weld removal, full-penetration welds, splice plates, doublers, an redesign of details fi improve fatigue life an comply wid class guidance.
Identification of fatigue-prone detailsCrack sizing and monitoring methodsStop-holes and crack arrest drillingFull-penetration weld repair stepsUse of splice plates and doublersDetail redesign to reduce hotspots
