1987 Volume 5 Issue 1 Pages 16-21
This study was carried out to achieve the granulation or grain refinement of solidification structure of fully austenitic stainless steel weld metal by pulsed TIG welding.
Welding variables examined in this study were the pulse frequency and the ratio of base current time (tb) to peak current time (tp) in a rectangular pulsed current wave.
The granulation or grain refinement of the solidification structure depended on the pulse frequency with the most effective refinement achieved at a pulse frequency of nearly 2.5 Hz and al. tb/tp of 9 to 10. The welding conditions in this case were a welding speed of 6 cm/min, average welding current of 50 A, and base current of 10 A.
The pulse frequency-dependent granulation or grain refinement could be explained in terms of the difference in the degree of constitutional supercooling.
