For CRAs, what is the maximum hardness of the weld consumable and the weldments?
Understanding the Hardness Limit of Welding Consumables in NACE MR0175
The inquiry is regarding a statement in NACE MR0175, Part 3, Sect A.2.3, which states that the hardness of the weld metal should not exceed the maximum hardness limit of the respective alloy used for the welding consumable.
Clarification on Maximum Hardness Limit of Respective Alloy
The person making the inquiry requests clarification on what the standard means by the “”maximum hardness limit of the respective alloy”” and where to find these values.
Response on Maximum Hardness Limit of Respective Alloy
The response clarifies that the maximum consumable hardness applies to the corresponding base metal (UNS number composition). It is defined as the maximum hardness that is listed in NACE MR0175/ISO 15156 for that UNS number or meets one of the defined alloy classes stated in the standard.
Undefined Answer for Non-corresponding UNS or Alloy Classes
However, if the consumable used does not correspond to an existing UNS or one of the defined alloy classes, there is no defined answer to the inquiry. The response directs to Clause 6.2.2 of ISO 15156-3 for a better understanding of weld cracking resistance requirements, particularly in this latter case.
Urgent Assistance for Welding and NACE MR0175
For urgent assistance in welding and NACE MR0175, one can reach out to the respective team.