I need to weld a small bit of mild steel to some hardened steel. Can it be done and tig or mig?
The background is that I have a gear selector on my vans gearbox that runs vertically into the box. There is a hardened steel skirt on the selector
with nodules pressed into it and the reverse light switch operates off one of them except mine doesn't because it's the wrong selector and
replacements are not easy to find. Can I weld mild to hardened?
I know it can be done but is tricky...
Would it not be easier to braze/silver solder the two metals together?
A lot of machine tools are a hardened steel tip brazed onto something softer/cheaper.
[Edited on 22/1/18 by tegwin]
Personally I'd go with Tegwin's approach of brazing or soldering since it shouldn't raise the temperature of the steel too much, otherwise you may end up creating a weak point.
I've never done any brazing. Is the joint strong? I wouldn't want it to drop off into the gearbox.
Some kit manufacturers braze their chassis, as do some motorbike manufacturers so it must be fairly strong. There are arguments that it’s better than
welding because you don’t embrittle the parent metals as you might with welding and risk a later failure. Also think about the example I gave if a
tool tip being crazed on. The forces being exerted on the ti in a lathe or mill are massive... I’d think if you braze properly you’d not have a
failiure on your application.
[Edited on 23/1/18 by tegwin]
[Edited on 23/1/18 by tegwin]
I didn't actually notice the last bit of your example on tool tips, sorry. Sounds a great idea, thanks very much for the tip. Informative and polite as always from this forum unlike others I've been frequenting recently.
quote:
Originally posted by mistergrumpy
I didn't actually notice the last bit of your example on tool tips, sorry. Sounds a great idea, thanks very much for the tip. Informative and polite as always from this forum unlike others I've been frequenting recently.
Regarding brazing I'm not sure it's an easy skill to master, but I do know that bicycle frame builders past and present use the approach - particularly on steel frames. I've also heard the term TIG brazing before, but must admit to not having looked into what this means or how it's done.
Funny you mention TIG brazing as that's what I came across last night. I have a TIG welder and was looking at brazing torches which seem to be quite expensive when compared to a blow torch. TIG brazing seems to be similar to TIG welding but using a different filler rod (simply put), the TIG handle being just a replacement source of heat. For my job I only need a piece around 20mm long by 10mm wide sticking to. I was wondering because of the piece sizes whether that would be an issue with overheating. I need to look a bit more into it.
Done a bit of Tig brazing (or more accurately bronze welding). Use Silicon Bronze rods, low heat (you're not melting the base metal), no flux and pulse sometimes works well. Good to use on thin steel.