Weld hardness criteria according NACE - SA-240 S31254

[weldpuzzle44]

Dear Engineers,

Could you please give me your opinion on the below questions that refer to NACE and hardness criteria?
Thanks in advance for your contribution.

Best regards,
Weldpuzzle44

Question:
What is the hardness criteria pertaining to Base Metal and Heat Affected Zone of weldments made of material SA-240 S31254 according NACE MR0175 (ISO 15156-3)?
If no criteria defined in NACE, does it make sense to use the criteria from material specification SA-240 (223 Brinell and/or 96 rockwel B)?

 

[metengr]

For solution annealed 254 SMO with a PRE > 40 there is no hardness restriction. The weld and weld region must not exceed the hardness of the base material.

Yes, you can refer to the solution annealed hardness of the base material per the material specification (SA 240).

 

[weldpuzzle44]

Thank you for your quick reply metengr.
I also found the below answer in NACE MR0175 interpretations (

http://www.iso.org/iso15156maintenance)

Answer to MP INQUIRY #2005-13
"There are no hardness limits for the HAZ of welds of corrosion-resistant alloys when there are no hardness limits in the tables or the text of the document for the base material”.

 

[CoryPad]

Proceed with caution regarding that statement.

The hardness of the HAZ after welding shall not exceed the maximum hardness allowed for the base metal, and the hardness of the weld metal shall not exceed the maximum hardness limit of the respective alloy used for the welding consumable.

Referring to SA240 and other standards is good practice.

 

[weldpuzzle44]

Absolutely, the absence of criteria in the standard does not preclude the manufacturer to follow good practice.