PQR Weld Hardness and Charpy Tests for CS Plates
PQR Weld Hardness and Charpy Tests for CS Plates
(OP)
Code: ASME Section VIII Div I / Section IX
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Lets say plate is A516 G70. Is hardness testing normally requested for in the PQR even if it is a non-NACE service?
Assuming it is a non-NACE application, what advantage does controlled hardness give us?
Thanks.
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Lets say plate is A516 G70. Is hardness testing normally requested for in the PQR even if it is a non-NACE service?
Assuming it is a non-NACE application, what advantage does controlled hardness give us?
Thanks.





RE: PQR Weld Hardness and Charpy Tests for CS Plates
Yes hardness measurements are normally requested for PQR.
Hardness measurements give you good info about the quality of the weld. Normally the base material, HAZ and the weld will be measured.
Excessive hardnesses could be the result of inappropiate welding by using incorrect parameters disqualifying the welds.
This has nothing to do with NACE (sour service), although NACE is specifying additional requirements for welding.
Regards.
RE: PQR Weld Hardness and Charpy Tests for CS Plates
The only time hardness testing would be requested is for temper bead procedure qualification or by an owner/user specification.
RE: PQR Weld Hardness and Charpy Tests for CS Plates
RE: PQR Weld Hardness and Charpy Tests for CS Plates
OK, although its indeed not a code requirement (ASME) we are mainly dealing with engineering specifications from clients (end users) wherein hardness measurements are indeed required to be included into the PQR.
Therefore I have stated 'normally requested'.
So far, realising that this is not a justification for saying that this is always required, I only experienced the hardness measurements as an obligation.
Do you have the same experience? I'm mainly participating in projects for the european market.
Whats your opinion, from a practicle point of view, regarding the value of hardness results related to the quality of the welds?
Thanks and regards
RE: PQR Weld Hardness and Charpy Tests for CS Plates
Let me phrase it this way, for the cost involved in obtaining hardness testing, it is not worth the benefit for use on P-No1 base materials.
RE: PQR Weld Hardness and Charpy Tests for CS Plates
Even more so on P1 steel PQR's because some mobs can tend towards the cavalier in these general type welds.
Cheers
Rob
RE: PQR Weld Hardness and Charpy Tests for CS Plates
1. The hardness values are normally required for PQR by company requirements (spec.) in order to prevent any crack (i.e. SCC, HE, etc.) during operation even though it is in non-sour service. For wet sour service (i.e. NACE MR 0103), please find Table 2.
2. Normally the hardness values required by company specifications for PQR of non-sour service are very similar with that of Table 2 in NACE MR 0103.
3. The hardness values may be based on the surface of HAZ (after PWHT when it applies).
4. If you apply the PWHT (but not required from ASME Section VIII, Div.1, UCS-56) to control the hardness values, you may use the mitigation of impact test requirement (temperature) in ASME Section VIII, Div.1, UCS-68(c).
Thomas Eun
Materials and Corrosion Engineer
RE: PQR Weld Hardness and Charpy Tests for CS Plates
Under ASME I have run across hardness requirements for un-fired vessels of materials with higher Mo content and special service vessels.