Thick plates of SS to Inconel are used in nuclear reactors to withstand high temperatures and pressures. This study is to evaluate the GTAW joining of SS316L to Inconel625 to evaluate the weldability; the temperature distribution in the longitudinal and transverse directions, resulting in distortions and the induced residual stresses. To obtain real-time temperature images Infrared thermography measurements were made. Similar welding joints of SS to SS and Inconel to Inconel were used as a reference for comparison with the dissimilar welding parts in this evaluation. Compatible Filler rods were selected: SS316 filler rod was used for welding of SS316L samples and ERNiCrMo-3 was used when a part is IN625. This study reports the temperature distribution for a SS to Inconel weld process and the resulting distortion and residual stresses were within the acceptable limits. © 2019 IOP Publishing Ltd.