Best Weld Filler for Higher Carbon Content 2

[tc7]

Our procedure for welding 304 SS (ASTM A204) to HSLAS-F (A1008 Grade 50) calls for ER309L (GTAW). Materials less than 1/2-inch thk. Preheat is 350F, no post weld HT. We have found the HSLAS-F to have slightly higher carbon than spec allows, .3% vs .15%. Is the ER309L filler still best choice?
Thanks.

 

[stanweld]

Since you are welding 304 SS, you can make the weld with ER309L, or ER309.

 

[metengr]

The lower carbon filler will have lower creep strength properties. IF creep strength is not a concern, stick with ER309L as stanweld mentioned.

 

[tc7]

Thanks Stan & Met.
Creep is not a concern for the application. Is the preference for the low carbon filler (309L) suggested so as to offset the high carbon in the HSLAS-F and minimize dilution? I read an article last night on "dilution" but the article wasn't clear what effect this has on weld strength or hot cracking.

Thanks.

 

[metengr]

Is the preference for the low carbon filler (309L) suggested so as to offset the high carbon in the HSLAS-F and minimize dilution?

No. The austenitic low carbon filler metals are used to reduce susceptibility to corrosion from sensitization. The ER309L should be used at ambient temperature service conditions. In your case, because this is a dissimilar metal weld, ER309L is appropriate. Dilution is not really an issue.

 

[tc7]

Thanks again Met-
Suppose my procedure stated ER309 and did not mention 309L (as I said in my first post), would I need to qualify a new GTAW procedure w/309L ? I cannot find an AWS document which provides electrode or filler metal groupings in the way B2.1 groups base metals.

Thankyou.

 

[metengr]

Suppose my procedure stated ER309 and did not mention 309L (as I said in my first post), would I need to qualify a new GTAW procedure w/309L ?

No.