316 pipe with 304 filler?

[atlantafab]

ANyone care to chime in on the resulting strength of 316 pipe and flange GTAW with 304 filler? I know it's not as corrosion resistant but, what are the structural sacrifices if any?

[atlantafab]

yes I should have used 316L but I used 309L (not 304)

[Wheelchair]

None, I accidently welded an x-ray 316L pipe, with 309 and after QA qualified the procedure it passed.


Wheelchair

[atlantafab]

wheel chair - thanks for the reply. No point of me selling the structural integrity - long story - so I cut it apart, got the grinder out (wish I had a lathe) and put it back with 316L. 2 pipes mushroomed from 4.25 hours to 10 hours ouch.

[usmcpop]

According to Lincoln, "316L or 316 applications generally require molybdenum and 309L contains no molybdenum."

From Azom.com, "The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments.".

[donald branscom]

According to Lincoln, "316L or 316 applications generally require molybdenum and 309L contains no molybdenum."

From Azom.com, "The molybdenum gives 316 better overall corrosion resistant properties than Grade 304, particularly higher resistance to pitting and crevice corrosion in chloride environments.".

316 does not "require" molybdenum, it contains molybdenum (4%) for the corrosion resistance below the waterline in salt water.

304 grade is used above the water line.

As far as 309 passing a x ray test, all that means is there were no holes and you had CJP, it does not mean the weld chemistry is optimal.

[usmcpop]

To clarify the comments from Lincoln, they meant that 316 parent material is used in applications where the Moly content is desired/required, and 309 filler would not match the Moly content.

[donald branscom]

To clarify the comments from Lincoln, they meant that 316 parent material is used in applications where the Moly content is desired/required, and 309 filler would not match the Moly content.

OK...I understand.

[sooeey2u]

ANyone care to chime in on the resulting strength of 316 pipe and flange GTAW with 304 filler? I know it's not as corrosion resistant but, what are the structural sacrifices if any?

To begin with, there is no such filler wire as 304.

There is however 304 base metal which is welded with 308 filler metal.

Base metal differences of 316 & 304 is 316 is higher in Nickel and the addition of Molybdenum

304
0.08 Carbon
2.00 Manganese
.045 Phosphorus
18.0-20.0 Cr
8.0-10.5 N

316
0.08 Carbon
2.00 Manganese
.045 Phosphorus
16.0-18.0 Cr
10.0-14.0 N
2.00-3.00 Molybdenum

[sooeey2u]

As far as 309 passing a x ray test, all that means is there were no holes and you had CJP, it does not mean the weld chemistry is optimal.

I concur.

On any project I have been associated with, QC would not have allowed that pipe weld to be put in service. Weld would have been rejected, cut out, rewelded and subsequent RT.

[Blacksmith]

We had a turbine application in corrosive service where the filler material was not matched to the base metal. (Attaching erosion shields) The filler material robbed the parent alloy with resultant corrosion and failure under centrifugal loading at the junction between the weld and the depleted base material. Agree that QA should not let the joint be placed into service. It may not be that the strength is compromised today, but if stainless was specified, corrosion may change the situation in service.