Arc Welder Power Supply for steppers

I searched and did not come up with any one else asking this question
so here goes. I have been looking for a cheap power source to power 3
Nema 23 steppers and I happened upon a DC arc welder for free. It
puts out 52 volts open circuit and 25 at max load (180 amps). I of
course never hope to hit 180A. But what I am wondering is if I dial
it down to its lowest amp settup ~30 could this be a viable power
source for my steppers? Would I need to run some resistors in line
with the welder to limit the current. I am thinking of adding a fuse
to prevent any high amperages from burning out the driver board or
motors. The steppers, I think, are around 6V so the ~52V from the
welder should work well.

Another related question I have is on the rule of thumb I see often
of supplying 20-25 times the rated voltage on the stepper motor. Does
this always hold true and for all Volt steppers. The reason I ask is
that I see some steppers rated for 12V. This would yeild 240+V power
supply requirements. From what I understand this higher voltage is to
get better responce from the steppers. At what point do you limit the
voltage. One sure limiter is the driver boards voltage limit but are
there others?

Many Thanks
Scott