Resistance spot welding (RSW) was employed to pre-join refractory alloy 50Mo-50Re (wt%) sheet with a 0.127 mm gage. Five important welding parameters (hold time, electrode, ramp time, weld current and electrode force) were adjusted in an attempt to optimize the welding quality. It was found that increasing the hold time from 50 ms to 999 ms improved the weld strength. Use of rod-shaped electrodes produced symmetric nugget and enhanced the weld strength. Use of a ramp time of 8 ms minimized electrode sticking and molten metal expulsion. The weld strength continuously increased with increasing the weld current up to 1100 A, but the probabilities of occurrence of electrode sticking and molten metal expulsion were also increased. Electrode force was increased from 4.44 N to 17.8 N, in order to reduce the inconsistency of the welding quality. Welding defects including porosities, columnar grains and composition segregation were also studied.
|Number of pages||9|
|Journal||Journal of Nuclear Materials|
|State||Published - Jul 1 2007|
Bibliographical noteFunding Information:
This work is funded by KSEF (148-502-03-74). Authors thank Dr Alan Male (University of Kentucky) for helpful discussions.
ASJC Scopus subject areas
- Nuclear and High Energy Physics
- Materials Science (all)
- Nuclear Energy and Engineering