Welding dissimilar metals

[amanites]

Can anyone tell me if there are any repercussions when welding stainless steel pipe to carbon steel pipe.I assume there exists transition weld electrodes but not sure if this practice can be applied to design of a chemical plant due to the ordering of wrong material.

 

[MJCronin]

You do realize that, for piping, this can be a flanged connection (mechanical joint) ?

 

[amanites]

Thanks MJ but problem is we have bought stainless steel socket weld valves for carbonsteel piping.I heard in the distant past of weld electrodes for welding carbon steel pipe to stainless steel but dont know if the practice is acceptable,the integrity of the weld etc.

 

[SJones]

http://www.google.com/custom?domain...000000;GFNT:0000FF;GIMP:0000FF;FORID:1;&hl=en

Steve Jones
Materials & Corrosion Engineer

http://www.pdo.co.om/pdoweb/

 

[JStephen]

I don't think it's any problem to make the weld, just that you may have dissimilar metal corrosion going on in the future.

 

[PAN]

amanites,
What will be painted on the welded joints?

 

[amanites]

if the line is insulated there will be a primer coat and if the line is not insulated there will be 2 coats plus a coded colour.Do you need to know the thickness or quality of paint?.

 

[PAN]

amanites,
Yes, I'm interested in your paint system on stainless steel surface and dissimilar welded joints. I do not worry about welding dissimilar materials. However, I worry about protective paint system for corrosion prevention. This is off-topic. Sorry for all.

 

[0707]

You can weld stainless steel to carbon steel, if you told us the spec of your SS it will be easy for the forum to give you the correct filler metal.


Regards

luis marques

 

[amanites]

Thanks Luis,the SS spec is 304L

 

[PAN]

amanites,

What is your design temperature?

All members,
This case is socket welding. Should we suggest him for dissimilar welding?

 

[0707]

To weld 304L to carbon steel you can use E310-15 or E309-15.

The problem related with this kind of weld is the possibility of galvanic corrosion.

regards

luis marques

 

[amanites]

Thanks once again Luis,do we have any idea how long before this corrosion starts to happen?