Keyhole gas tungsten arc welding of commercially pure zirconium

Keyhole gas tungsten arc welding (K-GTAW), a novel variant of GTAW, has been used to join commercially pure zirconium. The process enables single pass welding of 6.35 mm thick zirconium using conventional GTAW equipment and a high current torch, without expensive filler metal addition or joint preparation. The mechanical properties and the microstructure of the resulting joints were characterised. It is concluded that the K-GTAW process, with its high productivity combined with low capital investment requirements, can be successfully used for welding relatively heavy section zirconium.