Understanding NACE Hardness Requirements for Parent Metals

Someone recently inquired about the requirements specified in NACE MR0175/ISO 15156-2, 7.3.2 “”Parent metals,”” and NACE MR0175/ISO 15156-3, 6.2.1 “”Hardness of parent metals,”” and whether they pertain only to weldment parent metals or if they are also applicable to machined forgings.

What the Standards Say

The response stated that the stipulations outlined in NACE MR0175/ISO 15156-2 Section 7.3.2 apply to the relevant parent materials applicable to Part 2, which include carbon and low-alloy steels and cast irons. The parent materials also comprise forgings. Additional requirements can be found in Annex A, sections A.2.1.2 and A.2.1.3. On the other hand, the requirements listed in NACE MR0175/ISO 15156-3 Section 6.2.1 apply to parent materials applicable to Part 2, including CRAs and other alloys, which also include forgings.

What This Inquiry Specifically Addresses

This inquiry pertains to NACE MR0175/ISO 15156-3 Clause 6.2.1. Specifically, it addresses the requirements for hardness of parent materials applicable to Part 2, including forgings.