Welding A36 to 304L

[autiger74]

Guys,

I am considering an 8' diameter rotating cylindrical dryer that will have .375" 304L stainless shell near a burner and .375" A36 shell on either side butt welded together.
My concern is with the radial expansion of the two different metals at the butt joints. If the stainless expands much more than the carbon steel will that be enough to cause joint failures at the stainless to carbon joints? The maximum temperature the metals will see is approximately 800 deg. F.

 

[Duwe6]

Use the usual: 309L. Another good choice is Inconel 625, i.e. ERNiCrMo-3.
With 8-ft in diameter and only 3/8" thick, your degree of restraint is very, very low.

 

[tbuelna]

There will be some small amount of strain created at the weld joint due to CTE mismatch between the 304L cres and A36 mild steel. But unless the cylindrical shell ends create a very stiff structure at the weld locations, the joints should be OK. Of course, you might want to reconsider using A36 steel at temperatures of 800degF.

 

[weldstan]

Go with a nickel base filler metal, especially if the weld is subject to thermal cycling.