Chrome Moly to EN8 welding

[Harry_Worth]

Hi Folks, This is a post on behalf of a mate who's struggling with a project. He's just asked me if you can weld Chrome Moly to EN8. He's anticipating using TIG - This all a bit beyond me as a MIG user restoring an old British sports car!

 

[hotrodder]

Yep. Need more info to advise on the best flavour of filler wire... dimensions (i'm assuming the chromoly side is the related to the bending 4130 tube thread) and weld geometry. Regular er70s-2 (A15) mild steel filler is an undermatch on paper but if talking fillet welds to tube then weld size compensates some making it a better choice most of the time as the result is less brittle than with a stronger flavour of filler wire. Other times a higher strength wire like 312 stainless is better- designed for disimilar joints it can handle the dilution without becoming brittle/resulting in welds prone to cracking

 

[Harry_Worth]

Hi Hotrodder, many thanks for the info. Do you do consultancy if we need more help? Whereabouts are you based?

 

[hotrodder]

I'm in sarf east London and a tinbasher/welder not a metallurgist. Just ask away on the forum, preferably including details*. Send your mate to http://www.netwelding.com/Welding%204130.htm for a read up too

* for example any particular reason why he's using 2" x 0.125 wall 4130 when 1.625" x 0.083 is generally as big/heavy as rule books go for 4130 cage and 45mm x 2.5 / 50 x 2mm when talking T45. That one belongs in the other thread really though

 

[TechnicAl]

Well, I am a Metallurgist and I agree with the tin basher

hotrodder is too modest