AMSME lX QUALFIED OR NOT FOR X80 TO AISI 4130? 1

[drukvat]

We have Qualified X80 pipe to AISI 4130 flange acc to ASME lX With ABS witnessing Authority.

The Tube/Flange(21") is PWHT condition after welding. Now inspector says, that this procedure is not anymore
According ASME lX, because of the PWHT treatment,

The X80 Yield strength lowers the pipe mechanical properties to 550 Mpa after 4 hours.
This treatment we already did, because the 2hours is just giving us good PWHT properties, any way, if we must repair, we need to treat again. Does this inspector have right conclusion?

 

[metengr]

Sorry but I am having a tough time understanding your post.

Was the original welding procedure specification for joining X80 pipe to 4130 steel qualified with PWHT? How long was the time at temperature for PWHT?

If the procedure was originally qualified with no PWHT, you cannot simply add PWHT as an additional step. The procedure would need to be qualified for this step.

If the procedure was qualified with PWHT and you exceeded the total time at PWHT temperature, this is a nonconformance.

 

[drukvat]

Sorry it was not easy reading, i do mean that material properties of the pipe yield ( X80) are going down from minimum requirments as stated in ASME lX, for material in as welded condition

The Qualification was ok with PWHT 2 hours, and 4 hours, all qualified by witnessing ABS

the point is , does this WPQR still cover ther ASME lX standard if for this material requirments are give 620 MPA for the values meeting ASME lX requirments.

The Welding procedure is fine and ok, only my question is regarding strictely if i still forfill the ASME lX code requirments.

 

[stanweld]

The ASME IX Tensile Test Qualification per QW-152 and QW-153 specify minimum specified tensile strength - not minimum specified yield strength. In that case your procedure is qualified assuming that the tensile test met the minimum specified tensile strength of the X-80 material.

If your design is based on yield strength, you have not verified the design through the test. Noting that thermo-mechanical processing is more than likely used in manufacturing the X-80 material, its yield strength is negatively affected by the time at PWHT temperature. A lower PWHT temperature may well provide the properties desired.