Tig welding tips, questions, equipment, applications, instructions, techniques, tig welding machines, troubleshooting tig welding process
User avatar
  • Posts:
  • Joined:
    Sat Nov 09, 2013 12:33 pm
  • Location:
    Udall, KS, United States

A friend is building a three wheel electric car. He found some spindles and control arms from a 4WD ATV and had me turn axles to press into the spindles. The chip coming off the spindles when I was boring them out to accept the axles looked more like cast iron than steel, almost like black sand. I'd intended to tack them with ER70S6 wire in my MIG but worried that it might generate cracks in the casting so now I'm considering TiG brazing. The tacks would be only about 1/2" long on opposite sides. Would this be a good fit for material?

Thanks,
Rick
Attachments
One down and one to go.jpg
One down and one to go.jpg (57.56 KiB) Viewed 864 times
Boring boring boring.jpg
Boring boring boring.jpg (63.24 KiB) Viewed 864 times
Believe those who are seeking the truth, doubt those who find it
-Andre Gide
User avatar
  • Posts:
  • Joined:
    Thu Jan 06, 2011 11:40 pm
  • Location:
    Near New Orleans

I think you're on the right track...

I would lean toward a soldering/brazing process.

I am NOT a fan of TIG brazing. The penetration/heat soak is far too shallow. In your case I'd have to suggest a true (full heat-soak)brazing, whether with silver or bronze.

I broke a "TIG braze" joint three days ago with a 36" pipe wrench and about 60 seconds of serious heat. There was no penetration, just a surface bond.

Steve S
User avatar
  • Posts:
  • Joined:
    Sun Sep 22, 2013 10:14 am
  • Location:
    Minneapolis Mn 55407

Probably cast steel
As Otto says full heat brazing/silver solder
Everlast 250EX
Miller 250 syncrowave
Sharp LMV Vertical Mill
Takisawa TSL-800-D Lathe
Coupla Bandsaws,Grinders,surface grinder,tool/cutter grinder
and more stuff than I deserve(Thanks Significant Other)
User avatar
  • Posts:
  • Joined:
    Wed Aug 06, 2014 12:48 am
  • Location:
    Melbourne, Australia

It looks more like cast steel than cast iron to me. Cast iron will chip. It's unlikely that you would get swarf seen in the image from iron.
Moreover, the design of the piece obviously requires some strength. Cast iron would be less likely to be up to the task.
I agree about the heat soak brazing method too.

It looks like you have a pretty reasonable insertion length with the axles into the housing, and this will provide a good deal of support.

What material are the axles produced from?
EWM Phonenix 355 Pulse MIG set mainly for Aluminum, CIGWeld 300Amp AC/DC TIG, TRANSMIG S3C 300 Amp MIG, etc, etc
Sal Monella
  • Posts:
  • Joined:
    Sun Mar 01, 2015 9:08 am

Should be ductile iron. Ok to weld.

I would have machined an interference fit then heated the housing until it pressed together.

FYI other posters, if your TIG brazing has insufficient pen, you were not hot enough.

Note that TIG brazing is a misnomer, it is actually TIG bronze welding. The bronze will not flow through a joint as in furnace brazing, therefore sufficient veeing and melting of the based metal is required and the finished product is therefore a fusion weld. At 50K tensile, the strength of the bronze is not the weak link in a TIG bronze fusion weld.
User avatar
  • Posts:
  • Joined:
    Sat Nov 09, 2013 12:33 pm
  • Location:
    Udall, KS, United States

Trackranger, The axles are low carbon steel.

Rick
Believe those who are seeking the truth, doubt those who find it
-Andre Gide
User avatar
  • Posts:
  • Joined:
    Wed Aug 06, 2014 12:48 am
  • Location:
    Melbourne, Australia

lsamech104 wrote:Trackranger, The axles are low carbon steel.

Rick
LCS would be fine to bronze. I was just wondering if it was free-cutting, 1040 etc.

I note salmonella's comment about interference fit. That's great but won't allow the bronze to wick will.

It seems you've already machined the correct clearance fit anyway.

Plenty of gentle preheat on the casting, and let it return to room temperature slowly.
EWM Phonenix 355 Pulse MIG set mainly for Aluminum, CIGWeld 300Amp AC/DC TIG, TRANSMIG S3C 300 Amp MIG, etc, etc
Post Reply