ClassNK releases updates to its Guidelines on Laser-Arc Hybrid Welding (2016)

27 September, 2016 (Tokyo) – Leading classification society ClassNK has released Guidelines on Laser-Arc Hybrid Welding (Ver. 3) aiming to support the widespread application of laser-arc hybrid welding in shipyards.

Laser-arc hybrid welding is a high quality and highly-efficient welding process which combines both laser and arc welding methods, capable of achieving the same depth of penetration as the standard arc welding process whilst also inhibiting thermal deformation due to its low required heat input.

This guideline (Ver. 3) newly adopts accurate toughness evaluation methods and acceptance criteria in response to fracture pass deviations (FPD) which may occur during standard Charpy impact tests on the weld joints of laser-arc hybrid welding.

The Guidelines on Laser-Arc Hybrid Welding (Ver.3) are available for download on the ClassNK website for ClassNK “My Page” users. Registration for ClassNK’s “My Page” service is easy and free. Simply go to ClassNK’s website at and click on “My Page Login”.

*Fracture Pass Deviation (FPD)
A phenomenon which occurs when the fracture pass deviates from the hard and narrow weld metal part to the base metal during Charpy impact testing. When a FPD occurs, there is an increase in apparent absorbed energy making it difficult to accurately evaluate the toughness of the weld itself.

For more information on this topic please contact:

ClassNK Executive Operations Department

Tel: +81-3-5226-2047