The acceptable parameters were obtained only at a welding
speed of 3.4 mm/s in all cases of nitrogen contents in
argon shielding gas with a pulse frequency of 1 pulse/s, base
currents of 42±48 A, and pulse currents of 185±200 A, for
all welding positions. Fig. 8 shows acceptable base and
pulse currents in the ¯at, vertical and overhead positions
with a nitrogen content of 0±3%, v/v., a welding speed of
3.4 mm/s, pulse frequency of 1 pulse/s, and 55% on-time.
Table 3 summaries the appropriate TIG pulse welding
parameters for the 304L stainless steel with the ¯at, vertical
and overhead positions, a welding speed of 3.4 mm/s, a pulse
frequency of 1 pulse/s, % on-time of 55%, a root shielding
gas ¯ow rate of 8 l/min, and a shielding gas ¯ow rate of 16 l/
min. This table shows very narrow possible welding para