Standardization of Laser Welding Parameters for Attachment of Thermocouple to Pressurized Capsule for On-Line Creep Rupture Studies

Thermocouples are widely used in reactor applications due to their reliable performance in the reactor operating conditions. It is intended to use thermocouples to detect the in-reactor creep rupture of pressurized capsules. Attachment of thermocouple to the gas region of a pressurized capsule is a challenging task since the joint should withstand the high temperature and the associated high pressure at that high temperature. SS316 sheathed K type thermocouple of overall diameter of 1 mm is used in this study. Laser welding has been successfully adopted for this application, and this paper discusses the challenges involved, and the standardization of laser welding parameters to obtain defect- free laser welds.