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High Power, In-Vacuum and Narrow Gap Laser Welding

Back to Research Reports Elastic Follow-Up in the Context of Fracture Assessment Review of Process Simulations for Metal Additive Manufacturing Flaw Sizing Techniques Using Guided Waves Flaw Sizing Techniques Using Guided Waves Flaw Sizing Techniques Using Guided Waves 32221-2020-hybrid-composite-to-metal-joining 33557-2020-extreme-high-speed-laser-application-ehla-coatings 32893-2020-mechanical-fastener-coatings-for-corrosion-protection 33557-2020-extreme-high-speed-laser-application-ehla-coatings Applications, Modelling and Manufacturing Processes for Perforated Composites - Literature Review A Review of High Power, In-Vacuum and Narrow Gap Laser Welding Processes for Thick Section Welding A Review of High Productivity Additive Manufacture Using a Hybrid Laser-Arc Deposition (HLAD) Process A Review of Micro Welding with Fibre and Disc Continuous-Wave Laser Sources A Review of Residual Stress Measurement Techniques Used for Components Produced Using the Selective Laser Melting Process A Review of the Machine GTAW Ambient Temperature Temper Bead Repair Technique for Nuclear Power Plant Components A Review of Weld Repairs of Mar-M247 and Similar Alloys Butt Fusion Welding Procedures and Test Methods Used for PE Pipes Duplex Stainless Steel Welding – A Review of Current Practices In-Bore Multi-Positional Laser Welding In-Process Monitoring of Arc Welding for Quality and Defect Detection Mechanical Fastening Technologies for Steel to Aluminium Joining in Automotive Manufacture Process Capability Study for Friction Stir Spot Welding (FSSW) Resistance Spot Welding with Transition Discs – A Review of Dissimilar Joining Using Transition Materials with Specific Reference to Resistance Spot Welding Surface Modification and Micro-Machining with Pulsed-Laser Sources Wire Fed Electron Beam Additive Manufacture – A State-of-the-Art Review
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TWI Technical Literature Review 22958

By C C Hughes and C M Allen


A number of industries require welding processes for high quality, high productivity, low distortion welding of thick (>25mm) section metals, eg for pipe joining, pressure vessel manufacture or heavy support structures. To this end, multi-pass narrow gap arc welding techniques have been developed, but the productivity of these techniques can be an issue in some situations. Higher productivity electron beam (EB) welding is capable of thick section welding in a single-pass, but restrictions on use of some materials, and the requirement for welding in a vacuum, can dissuade some potential users from its adoption.

The welding of section thicknesses much beyond 25mm is still outside the capabilities of most laser welding processes. However, high power lasers (defined here as ?10kW), including modern fibre and disk lasers, can be capable of weld penetration depths in a single-pass at or approaching these values. Laser welding in vacuum, or at subatmospheric pressures at least, has also been demonstrated to increase penetration depth, even at more modest power levels. Section thicknesses >25mm have also been welded previously using a third process variant: multi-pass laser melting of a wire consumable in to a narrow gap/narrow groove preparation, in an analogue of narrow gap arc welding.

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