welding 321ss

Date 11-29-2005 20:03

I asked if anyone had problems welding 321 ss.. I have found that there is a small amount of contamination that seems to be my root cause. Since we are welding with no filler metal, I also have found that we are welding too hot..Even if the amperage is only 15amps. Using a heat sink to control the heat input seems to help a great deal. Does anyone have any other input that maybe helpful?? I also have been cleaning parts with a scotch-brite pad just before welding which also seems to help..

By Lawrence (*****)

Date 11-29-2005 20:21

When dealing with very low amps there are one or two more things you can do to effect your performance.

Electrode size and tip prep.

Down at 15 amps you will have better arc ignition with 0.040 electrodes.

Tip prep
A long slim taper will slightly reduce penetration (and burn thru)and widen your bead profile by creating a more bell shaped arc.
A short and radical taper will make a slightly more conical arc and increase penetration as well as directional control in fillets.

The radical taper may reduce arc ignition reliability slightly in some older power supplies, but the effect is usually not noticable.

A nice diamond wheel electrode dresser is a good thing to have when working with thin stuff.

I like this one:
http://www.diamondground.com/DGP.html

By Viv

Date 12-16-2005 13:46

To add to Lawrence's reply (and I think Lwrence helped me out last time too;-) we use 321 and had a lot of problems, these were traced to bad prep and a faulty argon regulator.

With 321 I cant stress enough the pre weld cleaning (every one else stressed this too;-), I tried scotch bright but found it still left some oxide, coudn't see it and the surface looked good enough to weld but if we use a fine flap wheel to clean first the result is a much better weld at lower temp settings, so I assume a little oxide was still left on the parent metal.

The second thing was getting the purge right, again I have found this makes a fundamental differance to the weld quality and the way the weld pool behaves, all this I learned from the forum as I am only a novice myself.

From experiance i can now say if you get the purge and prep right the differance you will find is like chalk and cheese!

Hope that helps