welding 4140 to st 37

[metaal]

hello,

I need info about welding (corner weld 2 passes) st 37 on a 4140 shaft. Can this be welded with 16%Cr and 65 % Ni electrode ?

 

[Metalguy]

Don't know what st37 is, but you should give a lot of consideration to the HAZ of the 4140, which will probably be quite hard and brittle if you don't use enough preheat. Post weld HT is better.

 

[sayee1]

Are you referring to ENiCrFe2 type of electrode? I.e. Inco-Weld A from |Special Metals for e.g. Refer this link for details

http://www.specialmetalswelding.com/products/incoweld/incoweldwea.htm

Yes, this consumable can be used for the application detailed. Refer to Metalguy's words of caution though.
Metalguy
for St37 refer following posts:
thread330-62886 refersa to St37 which is equivalent of S235
thread330-56039 refers to USt37-2 which is equivalent of A283
Finally see the last post in thread330-17608 which explains what St37 stands for!!!

Thanks and regards
Sayee Prasad R
Ph: 0097143968906
Mob: 00971507682668
email: sayee_prasad@yahoo.com
The whole of science is nothing more than a refinement of everyday thinking!!!

 

[metaal]

Metalguy,

Thanks for reply
Shaft will be preheated at 250degree C(482 degree F) . After welding, the shaft will be "insulated" during some time, so cooling will be slowly.

St 37 Analyse : %C <=0.17
%Si <= 0.55
%Mn <=1.60
%P <=0.04
%S <=0.04

 

[Metalguy]

Your intended preheat is pretty good, but I'd go even higher. What you want to do is avoid cooling thru the range of ~1,300 to 1,000 deg F too fast. This will allow time for the austenite in the HAZ to transform to pearlite.

I did a little study with a low alloy steel (P3) welded with the worst case-a single pass. Preheating to 400 deg. F. wasn't high enough, but we never did go back and try higher temps.

 

[JimMetalsCeramics]

Must you use that much Cr in a weld joint?

 

[metaal]

JimMetalsCeramics,

This is a proposal from manufacturer

 

[JimMetalsCeramics]

If your stuck with it, I would use a high preheat and a slow-cool down. But it's too Cr-rich for my tastes.