Weld to chromoly

[tiny]

I'm looking to fabricate or have fabricated a kickstand mount for a motorcycle frame. The frame is chromoly steel. I wont be doing the welding on this one (out of my league). But, I'm wondering what would be good choices of metal to do the mount with considering it will need to welded to a chromoly frame and be able to support about 500lbs. I looked into using 4130 and while the plate itself doesn't seem to be too expensive it appears the methods to cut it are (though I could be missing something). Any suggestions? Thx

[jontheturboguy]

Mild steel works fine. I prefer er80s-2 but youll start a hellva internet arm chair quarterback keyboard war if you ask what rod to use.

[skelley521]

From the American Welding Society, Welding Journal:

""When welding 4130 chrome moly in the normalized condition, AWS ER70S-2 filler metal, with its low carbon content; is the proper choice. If the part is to be heat-treated after welding, then a filler metal matching the 4130 chemistry should be employed. This requires preheat and special precautions to avoid cracking.""

[jontheturboguy]

When the aws starts crash testing chassis, you let me know.

[skelley521]

It's only a kickstand that the OP is asking about.
The article was on Nascar and stated for higher strength....
"The use of AWS ER80S-D2, which contains 0.50 moly, will provide a weld deposit with higher strength. When diluted into the 4130 base material, a weld tensile level of 760 to 800 MPa (110,000 to 115,000 lb/in.2) can be achieved. If this higher strength welding wire is employed, a minimum preheat of 65¡C (150¡F) is recommended. "

[zapster]

I have yet to see anyone preheat a chassis on a jig..
Just do it.

...zap!

[skelley521]

Originally Posted by zapster

I have yet to see anyone preheat a chassis on a jig..
Just do it.

...zap!

True, I have a buddy that use to buy his for years and now makes his own, but just because he doesn't preheat doesn't mean he is right either.

TECHNICAL BULLETIN....here.

They recommend...
"• Preheating and interpass temperatures of not less than 300°F must be used during welding."

Hmm, which is it, 150°F or 300°F....I dunno, over me head. Check the WPS

[tiny]

Thanks for the info guys, I really appreciate it. Not that I'd attempt it on anything critical, but am I to understand right that someone skilled (see why i'm not ready) could use 10018-d2 mr rod to stick weld this? (or if not mild steel to chromoly, maybe chromoly to chromoly?) Seeing as I might make hobby welder (at best) status at some point and that a lot of what I might find need to weld (in all honesty) would actually be chromoly steel this interests me. I figured at some point I'd get the attachments so I could use my machine for tig, but in all fairness if I found a rod that I could learn to use that would cover my chromoly needs then that's the route I'd prefer to go.

[bfastwelder]

Hi. I weld high alloy steels everyday. 4130, 4140, etc.... Light preheat getting the ghosting effect as I call it. You will be at 350 to 400 deg. Fer. Weld it with 70s-6 or 71t type wire leave no undercut and always pull back into your weld before finishing a stringer. Hell and for all honesty you can always use 309 stainless if your going to tig it up....

[tiny]

Thanks, I appreciate all the info. For now, I'll have any minor repairs done with the local welder/fabricator with mig. And now I have confidence in what to ask for (dont know his level of expertise yet). But unfortunately that's all he does and if I have any structural repairs, I guess I'll be in for a drive as I'd prefer to have those done with tig or oxy and I haven't found anyone locally to do these yet (small town). I guess I could have some luck with the welding instructor in the local community college.

For myself, I've been trying to read up as much as possible on using stick (as that's what I have). There is very little I can find about using stick on chromoly but seems that it can be done and that people know how but just haven't spoke much of it. From what I gather, it would need to be preheated (on a bike frame? I'm guessing some time under a propane torch might do). Then I could use 7018 but it seems that 10018 (expensive & hard to locate) might be the ideal choice. Followed with some post heating (again i guess the propane torch).

Would love to hear thoughts/info about using smaw on 4130, am i close at least? I know getting the tig attachments and learning that would be ideal but it's gonna be a while on a limited budget for now and it seems I should be able to repair it with stick.

[bfastwelder]

7018 will work fin 3/32 at about 80 to 95 depending on thickness of material. I would recommend atom arc from esab or Lincoln's excalibur. They seem to have always worked the best for me.