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welding cast iron and steel

Posted: Thu Jul 28, 2011 9:50 pm
by jhrusk
Can I use aluminum bronze to weld steel axle tubes to a cast iron center section or is there a better rod for this(strength wise).Thanks

Re: welding cast iron and steel

Posted: Fri Jul 29, 2011 8:52 am
by jpence38
The Aluminum Bronze A2 is a good filler for this application but it would best to not be a novice and try this. Heat control is critical. A2 has a tendancy to be "hot short". And for this application, it sounds as though someone could get hurt if not done properly.

Re: welding cast iron and steel

Posted: Fri Jul 29, 2011 9:20 am
by kermdawg
Hey try searchin the forums, I think I remember a thread about this about 3-4 months back in the mig forums. Good luck

edit-Did the hard work for ya-
http://forum.weldingtipsandtricks.com/v ... f=6&t=1259

Re: welding cast iron and steel

Posted: Fri Jul 29, 2011 12:36 pm
by jhrusk
Thanks for the replies,I am new to the site.I tried a search before posting but could not find anything,probably did not do it correctly.I would think welding this a little at a time would be the best bet to keep the heat input down.I am open to suggestions and thanks again.

Re: welding cast iron and steel

Posted: Fri Jul 29, 2011 9:52 pm
by Otto Nobedder
That center section will be cast steel, not cast iron. Big difference in carbon content.

I've had good success using preheat and 308/309 as fillers. My best guess is the carbon from the cast infiltrates the filler, but with 308 the carbon content doesn't reach the point where the weld is hard enough to crack.

This is not my specialty, so I suggest waiting for or seeking better advice. A lot of people do this every day. Look at the articles on powerblock.com. They probably discuss this, though I frown on some of their welding methods.

Steve

Re: welding cast iron and steel

Posted: Sat Jul 30, 2011 9:28 am
by jhrusk
Thanks for the reply Steve.I too questioned if it was cast steel or cast iron.most people said to do a spark test.When I was prepping the rearend I had to clean some brackets off of it so I was grinding on it and then I would grind on the center section to see if there was a difference in the sparks.There was definitely a difference,the steel tubes would throw long bright yellowish sparks while the center section had minimal reddish sparks and were short.This led me to believe it was cast iron and not cast steel.I am welcome to suggestions.Thanks,James

Re: welding cast iron and steel

Posted: Sat Jul 30, 2011 10:43 am
by turbo388
This isn't as critical as some seem to think, the tubes are pressed in (tight!!) and plug welded from the factory, and with big HP sometimes the diff housing can break the plug welds and rotate on the axle tubes. When that happens yes the axle is junk, but nothing falls out onto the ground or anything like that. Welding the tubes just stops it from twisting. Also, being a press fit with no sealant it's common to have slight leakage/weeping and welding the tubes stops that.

DCEN with 70S2/S6 or 309 will work fine. Or even stick with 7018.

Re: welding cast iron and steel

Posted: Sat Jul 30, 2011 1:37 pm
by jpence38
If the housing is cast steel, then you don't have to worry. It should be an easy weld. But, according to the sparks you said that were coming off of it, it doesn't sound like steel. If it is a cast iron and you weld it like it was steel, you will definitely have problems. I would definitely make sure what it is you are welding and not just guess and start slammin' weld to it. It could definitely ruin your day. Don't get me wrong about this, this is a good site with a lot of knowledgeable people on it, but there are also a lot who will just throw stuff out there to answer a question. When it comes to metal identification, I would not leave it up to a couple of guesses from a website. Others may not take this stuff seriously, but I do. There is always the potential to cause great loss when giving advice whether it is in time, money, or injury. And I am not singling out any particular response on this post, so don't take offense . :)

Re: welding cast iron and steel

Posted: Tue Aug 02, 2011 4:22 pm
by turbo388
No offense taken ;) , and I'd definitely agree with assessing this with an overabundance of caution IF it were a new build-up from scratch, or totally replacing the factory tubes in the original cast diff housing (it happens, but rarely and the people who dive into those sorts of things tend to know what they're doing). Even shortening the axle tubes and/or swapping to a different style bearing flange requires a centering jig & fixtures not common with DIY types.

If the new weld between the original tubes and original diff housing fails, it'll fail in the same manner as if it'd never had the new weld in the first place.

Re: welding cast iron and steel

Posted: Tue Aug 02, 2011 8:44 pm
by jhrusk
Thanks everyone for the replies,well after much searching and deciding how I was going to go about this,I made the decision to go with a high nickel rod.I got a stick rod and removed the flux and cleaned it very well.I used my tig to weld the rearend and I skipped around a little,it welded very nice and I tried to keep the heat input down.After it cooled I checked it with an alignment bar and fortunately everything stayed in line.The rods were $16 for four rods but given the results they were worth it.Thanks everyone.

Re: welding cast iron and steel

Posted: Mon Dec 05, 2011 3:46 am
by TheExpert
Aluminum bronzes are most valued for their higher strength and corrosion resistance as compared to other bronze alloys. So this is good one.

Re: welding cast iron and steel

Posted: Mon Dec 05, 2011 3:48 am
by turbo388
TheExpert wrote:Aluminum bronzes are most valued for their higher strength and corrosion resistance as compared to other bronze alloys. So this is good one.
Will somebody give this spambot the boot already?!