cutting stainless and hastelloy

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Hello,I have a bit of a problem.  I have a Hastelloy cylinder welded to a (what I believe to be stainless steel) plate.  I need to separate the 2.  I was thinking of using a oxy-acetylene torch to cut at the welds or melt the welds.  I went to the gas shop and the girl told me that oxy-acetylene wont cut stainless.  I thought that the 3200*C flame would not care and burn right through.  But through some research I discovered "The oxygen chemically combines with the iron in the ferrous material to instantly oxidize the iron into molten iron oxide, producing the cut" and stainless has a reduced amount of iron (however my stainless does have oxidation).  Also I heard the Nickel in the hastelloy is pretty tough stuff. for the first time in my life I'm hoping the dirty stainless is in fact steel, but I don't think so.I'm wondering if I should even try the oxy-acetylene and attempt to "Melt" the welds, or would it just re-pool and give me more head aches.  The stainless plate is about 1.5" thick.  Are there special saw blade that can handle this cut, if I was to cut it like a pie.  -Brett
Reply:Sounds like a job for an Air-Arc rig.
Reply:Plasma would take care of it pretty easy, how thick is the cylinder?
Reply:The hastelloy (cylinder) is roughly 1in thick at the point of weld.
Reply:Originally Posted by welds4dSounds like a job for an Air-Arc rig.
Reply:Plasma cutter, all the way. Use it to arc gouge the material if it is too thick to cleanly cut in one pass.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:I love my air arc, but you will need a large stick welder, and a high cfm air compressor.  200-250 amp bare minimum but bigger is better.Bruce DeLaetHeavy Equipment Mechanic and Welder1948 SA-200 short hood1949 LincWelder 1801963 SA-200 red faceMiller S-32-P
Reply:Plasma to cut the two apart.I do have to ask, though, what do you plan to do with either part? Hastelloy is unforgiving to work with in my experience. I tried to clean up the sufrace of some one time with a a razor sharp carbide end mill and it wouldn't even touch this stuff!If you plan to salvage the materials for use later on, I would be really curious what you  have in mind. Just not good for "common" jobs.Granthttp://jackalopefab.com/MM210Synchrowave 200DXMiller XMT350 w/60series feederMiller Bobcat 250 with SGA 100 and spoolgunHTP PlasmaFull Machine shop with everything
Reply:Grant- I plan on scraping the the metals, I don't know what I could really do with the 2, the shapes are awkward.  They were originally custom built, so its not like the part can be resold.  And at the price the scrap yard was paying it was totally worth investing in a cutter of some kind.  However the $1000 plasma cutters I looked at could only cut up to 5/8" max.  I know of a few machinists in my area who might possess a cutter of this needed magnitude.  Unless I could make several cuts with one cutter, or does it not leave a wide enough track to retrace a cut?  Im totally new to heavy machining, I came from an electronics background with light duty fabrication.  Thanks everybody.......
Reply:a good steel shop should have a band saw that would easily cut itHave we all gone mad?
Reply:If he is dealing with a vessel worth well over $1000 in scrap and has wall thicknesses in excess of 5/8" it may be hard to fixture in a band saw.  I was going to suggest a grinder with a cut-off wheel but I was thinking thickness in the 1/8th inch realm initially.What about thermal lance?  SLICE or comparable.  A little less expensive for initial purchase than plasma and will cut anything.
Reply:I have cut 1" plate and railroad track with my little Hypertherm 600 (now the Powermax 45). Post your location and find some body with a cutter and pay them to sever it for you.
Reply:Originally Posted by Rotten Kidwhat would something like that cost?  I went to thermadyne's website, the torches are like $400, now would i need a system to drive that or does it just plug into the wall.
Reply:Plasma would be my choice. It is much cleaner, safer and more quiet than arc air. I have gouged lots with my plasma, works great for that.Oxy fuel will not cut stainless steel.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:For gouging with plasma on a thick part it's not too hard. Kinda like cutting a tree with an axe. You bevel a cut in with it at one angle. make another pass at another angle, dissecting the first angle. You can clear out say 3/8" worth of material like that. Then, if you were trying to cut say 5/8" material, you would have a straight shot 3/16"-1/4" cut left to do. I cut some 1" material with my puny little Lincoln PC25 this way. 3 passes of 1/4"-5/16" removed, and then a final sever pass. No portaband blade alive would have done the job; it was 17-4 S.S., heat treated to like a Rockwell 44. The project was pretty straight forward once I figured what I was going to do, and then I just went after it. Air chisel worked well to knock out the cut wedge and dross.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:Have you tried a cut disc on a 4 1/2" grinder?I use em all the time on stainless, cutting stuff up to 1" thick and thicker. They only cost a couple bucks each, as opposed to a grand or two for a plasma cutter.Wear a full face shield and earplugs.
Reply:If I remember correctly, One issue with plasma cutters is the voltage.  Most TIG/Stick welder use 30V open circuit.  The plasma cutters run something like 60V while pushing amps.  So you get a 60 Amp machine at 60V and you are driving as much power as that 350 Amp stick welder.Someone once said the Hypertherm sales rep cut 2" still with the powermax 45.   Really slow and I'm sure duty cycle will come into play, but gives you an idea what can be done.I have the 1000 (older series) which is a 60Amp cutter.  Above that size I'm pretty sure you are talking about a 3 phase setup.  Certainly not a 50A/230V.   The machine will cut 1" steel pretty easily.  Not sure about stainless.Call around to the LWSs and see if they will rent you one.Con Fuse!Miller Dynasty 350Millermatic 350P-Spoolmatic 30AMiller Multimatic 200Hypertherm PowerMax 1000G3Miller Maxstar 200DX
Reply:A picture may help with ideas.Millermatic 200Hobart Handler 120Victor O/A & Ramco BandsawLincoln 225 ACSnapOn AD HoodMiller XMT304/22AHypertherm Powermax 1650 G3Lincoln Idealarc DC600 w/Extreme 12 VSMiller Digital Elite "Joker"
Reply:plasma all the way! a 80 or 100 amp unit ill cut it clean! find someone local!