Secrets of Stainless...

[davek0974]

Hi all, long time since

I have a possibility of a batch job, did a test piece tonight and it was not as good as expected, 3mm 304 stainless steel, disc is 90mm dia.

Part was cut with 3mm over-burn, no torch-off rule, 3mm lead-in, 45A, 3700mm/min.

Even with the over-burn it has left a big tag on the parts???

So, what can i try here, i want them a bit better naturally

[SeanP]

Same here on stainless Dave, I don't really do much though, I get that on steel over 10mm and use a slow down rule to catch that tag, 2.5mm before end feed rate 40% (include lead out unchecked)
Might be worth a try, you will probably have to experiment a bit the catch it.
Im keeping away from stainless Lettering, too much cleanup for my liking.

[davek0974]

Hi Sean, hope things still going well

I'll try the slow-down on the next test, I was hoping a 3mm over-burn would do it but it seems to make no difference?

I tend not to use lead-outs on internal cuts as if the waste falls, the torch is cutting in air which blows the nozzle, thats my theory anyway

I'll play with slow down.

[ajk2004]

I'm sure you can find several tips on cutting stainless here. One thing that's obvious is that your torch is riding too high, that's evident by the top dross.

[davek0974]

Hmm, that's odd as it usually runs at the right height, i'll have to dive in and do some tests i think as soon as i get a break.

[Gamelord]

Stainless is quite different than steel. I always use a lead in and lead out when cutting or I end up with what you have there, unfinished cuts and divots. Also, make sure you are going the right direction or you will get increased bevel on your part, usually much worse than with steel. I always get more dross with stainless than with steel....it doesn't actually look that bad on your cuts. Keep running tests until you get what you like. Once you get it dialed in it works pretty good and you can get some good results.

[sphurley]

http://www.plasmaspider.com/viewtopic.p ... 933#p71529

[plain ol Bill]

Yeah, what Jim said if you follow the above post. The tip is CLOSE, .02 when cutting. Pierce it as close as you dare and get the torch down to cut height QUICK.

[davek0974]

Will have to play with this i think, might also try the fine-cuts on it.

[jimcolt]

The best cut will be with the Finecut consumables at the cutting specs listed in the Powermax operators manual. Height, cut speed, amperage are critical. Jim Colt. hypertherm

[davek0974]

Thanks Jim, i will be "going back to book" with this as soon as i get a gap.

I did try some at the weekend and improvements were found by piercing at 3mm and cutting at 0.5mm &45A on the 45A consumables plus adding a slowdown to 40% for the last 2mm with a 1mm over-burn, no lead-out.