Weld cast iron and mild steel

[Iron Falcon 72]

I'd like to weld a discbrake rotor to the top of a a mild steel post to mount a machinist vise to. So far internet searches have turned up a lot of pre/post heating for cast iron welding. I don't have the facilities for that. I did a bit of it in school no problem but that was cast to itself not mild steel.

Is this a bad enough idea that I should figure out how to mount it with bolts? Or would a braze hold well enough to hold the twisting and turning on the vise?

[Thomas Dean]

Yes you can weld cast to steel but the best way is to braze it. IMO. I have used a 6" bench vise that had the back jaw brazed back on. It had been broken back in the late '40's and the owner repaired it using brass. I worked for him from '73-'76 and he had that vise in the shop. We did everything we wanted to with the vise and with no hesitation. I am a firm beliver that a better repair of cast iron is with using brass altho there are good products on the market but they are real pricey. Why not use a piece of 1/2" steel plate, drill hole to match the vise base and then weld to the top of said post?

[Bryce Masuk]

you can weld cast iron with Nirod with a stick,

or you can mig weld it

for this applicaton you should be fine with a mig or stick weld
typically a disk brake is more dense than most cast iron items, because of this it shouldnt be a problem to weld as long as you clean it as best as you can grinding it down abit would be best

[ironwolfforgeca]

are you sure rotor is cast Iron ?? use a cutting torch an test if it cuts its steel or if it melts its cast then you know what you have ? then you can test rods 7018 /stainless/
nirod/ mig there are many more to try :)

[Jocko 58]

HI You can weld cast to mild steel With Stainless Steel welding rods, put a bit of heat to cast first
Onya :rolleyes:

[Iron Falcon 72]

It's probably ductile iron (cast w/a fancy name). I was able to get a 1/2" sq steel rod to stick. It looked like a good weld but when I gave it a jerk it just popped right off. The weld broke in the disc. Nice greyish color. I'll probably do the braze. That would be easier for me then fabricating a new mount plate.
I hadn't heard of using stainless rod. I assume it's an stick process.?

[JNewman]

Weld to the studs they are steel. You can either weld a plate with holes for the studs and bolt on or just weld the studs direct.

[Dragons lair]

Not all rotors have studs in them. I have a few of them.
Ken

[horseshoe182]

I have welded cast iron many times with stainless steel rods, stick or tig.


This leg on a guilotine was welded up with S.steel rods many months ago, it is still in good order today.

[Bryce Masuk]

What machine are you using? and what is the amperage with what size rod?

if you have a machine that runs on 220 you will be able to weld them if you know what you are doing

[horseshoe182]

Are you asking me Bryce?
If so, I used an Esab Caddy welder ( small DC mobile welder) I would have used 2.5mm 316 S,Steel rods with amps at about 75-85, and no pre-heat. Not to high with the amps when welding S.steel out of normal position, because the weld pool will runaway on you. This job can be done with any AC or DC welder, no trick welders needed. I use S.steel on all of my cast welding.

[Bryce Masuk]

sorry horseshoe I wanst asking you however it looks like you got the job done,

the question was for iron falcon
i dont understand why he couldnt get it to hold together unless he was using the a 110 machine or with a large rod or something like that

[Iron Falcon 72]

sorry horseshoe I wanst asking you however it looks like you got the job done,

the question was for iron falcon
i dont understand why he couldnt get it to hold together unless he was using the a 110 machine or with a large rod or something like that

I'm using a Miller 180 with 1/8" 6011 rod. About 90 amps DCEP. It made a nice looking weld but snapped off in the HAZ of the brakedisc revealing a very light grey cast iron-looking surface.

[RcRacer]

If you say it snapped in the HAZ then my guess would be the cast iron got too brittle from too rapid a cooling. If you weld cast iron with nickel rod and then cool it slowly, it should help prevent it from getting brittle and cracking.

Edited July 15, 2009 by RcRacer

[JeremyP]

6011 is definatly an improper rod to be welding cast to steel. Like previously stated a stainless rod with lots of nickel alloyed in it will be much more successful for you. You can buy small packages of 'nirod' or 'tricast' smaw electrode at welding supply stores easily. Most salesmen will be able to help you choose a rod that will work if you ask, since each company uses different trade names for their products. If you have access to a torch and brazing rod you can also braze it which can be just as effective as long as everything is super CLEAN. Good luck!

[Vinlander]

The key to welding cast with stainless steel is overcoming "expansion," wherein the weld filler cracks laterally across the bead. While the weld is still hot, peen it with a small hammer. This peening with cause the weldment to "compact" slightly, kind of like forging, and will defeat the expansion/cracking. Weld an inch and then peen it.

It is also important to oscillate with an arc welder rod so you can effect maximum burn in, rather than simply filling the void between the cast and the steel.

Good luck.

Vinlander
[email protected]

[sfDuck]

Hey! I just read your dillima and found myself in the same pickle ! So I tried the 7018 rods; since I had some on hand, and guess what. It worked first time out. You guys are always amazing me with what I can do. I had a hole to file in some cast, and I know it was cast because it had that granular look at the break. So I tried it, my old stick welder acted up a little to get things started so I bumped up the amps and bumped up the amps till I was at the limits and walla it worked. Once I had a good coating of 7018 I filled the rest with 6014 on top. When I ground it out you couldn't see it! Thanks fellas.