welding stainless to steel

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I know this question probably gets asked a lot, but can I weld mild steel to stainless steel?   I only have a 110V MIG so it will have to be stick welded.  The mild steel is 3/8" and the stainless is 1/4" diamond plate.  It's for a bumper on a Jeep.  ANY help, comments, suggestions are appreciated.  Thanks.
Reply:Originally Posted by cutlerfarmerI know this question probably gets asked a lot, but can I weld mild steel to stainless steel?   I only have a 110V MIG so it will have to be stick welded.  The mild steel is 3/8" and the stainless is 1/4" diamond plate.  It's for a bumper on a Jeep.  ANY help, comments, suggestions are appreciated.  Thanks.
Reply:what I meant was...my Mig is only 110V, BUT... I have a 220V Arc welder.  So it can be done.  What should I do as far as prep?  Do I need to heat one of the metals first?  Is it going to be a huge pain in the butt?
Reply:no it should be pretty straight forward provided 309 rod can be run ac. I've never tried it on anything but dcep.
Reply:I figured as much but just wanted to clarify....some people have some crazy ideas, ya know?  Any more info on how/what you're doing? You say it's for a bumper on a Jeep.....can you elaborate or post some pics?http://all-a-cart.comWelding Cart Kits and accessories
Reply:run it ac?  what is dcep?  The stainless steel diamond plate was given to me 5 years ago as payment for rebuilding the axle in a co-workers jeep.  It's been sitting out side the last 5 years, has no rust, and is not-magnetic.  As far as what kind of stainless steel this is, all I know is that it was used by the Coast Guard.
Reply:I have a piece of 3/8" steel from the broken extend a hoe off of my CAT backhoe.  It measures 5"x7" tube. I want to cut it up and plate the front of the frame and extend the 3/8" mild steel through the bumper.  The bumper would be the 1/4" diamond plate stainless, which I need to have bent into a 2"x5" square tube.  The horizontal is the 2"x5" bumper and the "l" represent the 3/8" steel plates.  The extend through the bumper to provide points for tow hooks.  It doesn't look right after it gets posted....                         l                                l                         l                                l              -----------l--------------------------------l--------------                         l                                l
Reply:Just get 309L electrodes for your stick welder.  3/32 will make that weld no problem and cover just about everything else you'll need to weld.  Run it hot, especially if you use an AC welder.  Vertical welding is more difficult because of the thick slag so try to do all of our welding in a horizontal position.
Reply:Holy chit!  A 1/4" stainless bumper?!?  Don't forget to re-adjust your headlights after mounting....My name's not Jim....
Reply:my wife destroyed the stock bumper on Sunday when a guy decided to stop in the middle of the intersection so I figured now would be a good time for an upgrade.  I'm still trying to decide on whether or not to use the stainless I have, or just buy a piece of 2x4 mild steel and weld it up.  The stainless diamond plate looks soooo cool though.
Reply:I've only ever seen 1/4" s/s checker plate once. Not to be an a$$hole, not knowing your expertise, you sure it's not aluminum?.....Mike
Reply:You can spend the extra money for 309L rod if you want but I would just weld it with 7018.  Welding the SS to mild steel is going to make the weld rust anyway so why spend the extra on SS rod.  Could be SS tread...I have some drop pieces of it at the shop from previous jobs but measure twice, cut once cause that chit is NOT cheap.Whatever you decide to do take pics when your done so we can see how the new bumper looks
Reply:Originally Posted by cutlerfarmerwhat I meant was...my Mig is only 110V, BUT... I have a 220V Arc welder.  So it can be done.  What should I do as far as prep?  Do I need to heat one of the metals first?  Is it going to be a huge pain in the butt?
Reply:Stainless is tough stuff to work with.  How are you going to cut it?  How are you going to bend it?   I have only bent 1/4 inch stainless once, used my O-A torch to get it red hot, and then hit it with a big hammer.   Not easy to bend, even hot.  I had some 1/4 inch plate rolled in a huge industrial shop for me, they did it cold with big machinery, saved me a lot of work, even though I could have done it myself with a torch and a hammer.I too have never seen stainless diamond plate, but I have seen plenty of aluminum diamond plate.   The weight usually gives aluminum away.  Plus aluminum cuts fairly easily with a hacksaw.RichardSculptures in copper and other metalshttp://www.fergusonsculpture.comSyncrowave 200 Millermatic 211Readywelder spoolgunHypertherm 600 plasma cutterThermal Arc GMS300 Victor OA torchHomemade Blacksmith propane forge
Reply:Originally Posted by Fat BastardUm they are both arc welders, NO?
Reply:Inconel is the rod you want to use.I won't act like my dad and ask you how stupid you are.Stainless Steel expands at a faster rate ( something like 3 or 4 times more then carbon steel).  So when you weld two dissimilar metals together, the weld usually cracks - because they also cool at a different rate.http://en.wikipedia.org/wiki/Inconel
Reply:Originally Posted by Booger WelderInconel is the rod you want to use.I won't act like my dad and ask you how stupid you are.Stainless Steel expands at a faster rate ( something like 3 or 4 times more then carbon steel).  So when you weld two dissimilar metals together, the weld usually cracks - because they also cool at a different rate.http://en.wikipedia.org/wiki/Inconel
Reply:The piece measures 6'x3'.  It's NOT aluminum, it's beyond HEAVY.  Like a said the guy I got it from was in the Coast Guard and I'm pretty sure he "borrowed" it from them.  I've had this damn thing for 5 years now and I've never known what to do with it until I got this Jeep.  I talked to Consolidate Metal in Fresno, CA and they said they can cut it and bend it, but it's not cheap. I don't have access to a plasma cutter and I don't know how I would bend it anyway.  I plan on making my rock rails and bumper out of this stainless piece.  I figure it will cost me as much to have this cut and bent as it would to go out and buy the mild steel I would use otherwise.  This will just look different than every other black Jeep bumper.  Just curious, what would this piece cost?  anyone know?
Reply:Originally Posted by cutlerfarmerThe piece measures 6'x3'.  It's NOT aluminum, it's beyond HEAVY.  Like a said the guy I got it from was in the Coast Guard and I'm pretty sure he "borrowed" it from them.  I've had this damn thing for 5 years now and I've never known what to do with it until I got this Jeep.  I talked to Consolidate Metal in Fresno, CA and they said they can cut it and bend it, but it's not cheap. I don't have access to a plasma cutter and I don't know how I would bend it anyway.  I plan on making my rock rails and bumper out of this stainless piece.  I figure it will cost me as much to have this cut and bent as it would to go out and buy the mild steel I would use otherwise.  This will just look different than every other black Jeep bumper.  Just curious, what would this piece cost?  anyone know?
Reply:cutlerfarmer,Since that piece is "non-magnetic" you could sell it to Pinjas for a new top for his welding table.  Take the proceeds and buy new metal to build any bumper you want,Stainless steel in 1/4" is easy to shear.  Most larger fab shops could do it for you with no problem.  Not a big fan of cutting SS with hand held plasma.  Edge still has to be ground to remove the oxides.  CNC plasma cut using nitrogen is a different story.  For that size piece, we'd either shear it or cut it with the water jet.Use the 309 rod and you'll be fine.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:If you use 7018 to weld SS to mild steel, yes the weld will rust quickly.If you use the proper rod for the job like 309L it will cure the rust problem in the weld.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:shoot, if I could be a couple hundred bucks for it, I'd probably sell it.  If I had a shop I'd keep it for a welding table.  Sooo, do you guys think I'm wasting a good piece of SS on a bumper for a Jeep?  I'm just tired of looking at it and wondering what the hell I'm gonna do with it.
Reply:The issue with welding SS to CS is controlling the chemistry of the weld pool so that it remains austenitic, non-hardenable, and ductile, not martensitic, highly hardenable, and brittle.  309 SS filler will generally give the proper chemistry for welding a 300 series SS to CS.Even though you may produce a ductile weld by choosing the correct filler, the heat affected zone of the CS may have poor ductility if CS has high carbon or is alloyed, and the cooling rate is rapid. See some older posts on this topic:http://weldingweb.com/vbb/showthread.php...&highlight=309http://weldingweb.com/vbb/showthread.php...ess+steel+mildhttp://weldingweb.com/vbb/showthread.php...&highlight=309http://weldingweb.com/vbb/showthread.php...&highlight=309http://weldingweb.com/vbb/showthread.php...&highlight=309