Welding 304 to 304L

[steadag]

Hi all,

Are there any problems with welding SS 304 to SS 304L? The weld in question is between two 3'' Sch 40S pipes.

Thanks.

 

[metengr]

There should be no problems with weldability between 304 and 304L. Use 308L filler, keep your interpass temperature below
250 deg F to avoid any more heat input as necessary for 304 stainless steel.

 

[DVWE]

metengr,

What about an interpass temp of 350 deg F? That is what I have most commonly seen and approved.

 

[metengr]

The 350 deg F is ok, but I like to enforce a lower temperature especially when 304 (higher carbon version) is used to reduce susceptibility to sensitization.

 

[EdStainless]

If you have MTRs check and see if the 304 is really 304L, it may be.
There is no reason to weld with anything other than 304L filler, unless the weld must have some special properties.

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P.E. Metallurgy, Plymouth Tube

 

[metengr]

304L filler? 308L works just fine because you have no 304L filler in SFA 5.4 or other SFA filler metal specifications.