308 Stainless Rod For Carbon Steel?

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I believe 309 stainless rod is recommended for carbon steel........is 308 stainless rod okay?If not.......why?
Reply:308 is a stainless rod, primarily for 304 grade SS to itself.  309 is primarily for joining stainless-to-carbon steels. For standard carbon/mild steel to itself you need ER70xx rod. 1st on WeldingWeb to have a scrolling sig! HTP Invertig 400HTP Invertig 221HTP ProPulse 300HTP ProPulse 200 x2HTP ProPulse 220MTSHTP Inverarc 200TLP HTP Microcut 875SC
Reply:You could use 308 to carbon for none critical/ none code compliant  applications
Reply:http://www.lincolnelectric.com/en-us...al-detail.aspx.  309 for welding stainless to mild steel, 308 for fusing austhenitic stainless to stainless.  If you are asking can 308 be used to fuse mild steel to mild, then the answer is "yes", but "not recommended".  You definitely won't see any WPS and code work spec'd for mild to mild steel using 308 filler.  See post #2 of http://www.millerwelds.com/resources...ainless-filler.  The resulting low Ferritic Number after mixing (dilution) can result in hot cracking.Last edited by ManoKai; 08-10-2014 at 05:59 PM."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:What are you welding? I use 308 L 16 on many things, mostly because I'm too lazy to dig out my 7018 from the truck. If it's for you and not a critical weld, I don't see why not. But that depends on the project at hand.Thermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter
Reply:This is what I used the 308 stainless on. This is a buffer of sorts. Goes into the receiver hitch. The friend that I did this for backs his truck up against a wall.......this will protect his rear bumper.
Reply:There is no way in he!! That is coming apart. I'd worry more about the wall he's backing into. You might need to install some rubber or vinyl bumpers on the wall.Thermal arc 211iCk flex-loc 150 & 130Clamps, saws & grindersHarbor freight 80 amp inverter
Reply:The issue with using 308 to weld mild steel is the weld itself will not be resistant to rust. It will be mixed with the mild steel enough that it will not be corrosion resistant. 309 rod contains extra alloys to ensure a corrosion resistant weld when joining mild steel to stainless steel. Considering the cost of stainless welding rod, I'd be using 7018 rod for welding mild steel to mild steel. That would lower the weld cost of this job significantly.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:Originally Posted by snoeproeThe issue with using 308 to weld mild steel is the weld itself will not be resistant to rust. It will be mixed with the mild steel enough that it will not be corrosion resistant. 309 rod contains extra alloys to ensure a corrosion resistant weld when joining mild steel to stainless steel. Considering the cost of stainless welding rod, I'd be using 7018 rod for welding mild steel to mild steel. That would lower the weld cost of this job significantly.
Reply:The other reason that 308L filler metal is not recommended for welding mild steel is that under certain conditions, the welds will suffer from hot cracking problems.  Whether or not hot cracking occurs mostly a function of 2 things:1 -  how restrained the joint is(yours was not excessively restrained),2 -  how much dilution there is with the base metal.There's risk that the corrosion resistance of the weld won't match that of the base metal; which is normally 300 series stainless.  In your case this doesn't really matter.Since your weld didn't split down the middle immediately following your laying the bead down, I'd say you're OK.  There can be hot cracking issues welding stainless on steels that are contaminated with sulfur and phosphorus as well.  Again, not so much an issue in your case.The other big reason using 308L isn't recommended is it costs a lot of extra money to use it; when much cheaper ER70S-6 will do the job cheaper and with fewer potential issues.Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector