Hardness Requirements for Materials Selection in NACE MR0175

This page aims to answer questions about the hardness requirements for materials selection in accordance with NACE MR0175. While the first section offers information on the limitations of using 22HRC as a hardness requirement, it also advises examining the specific material’s requirements for full compliance.

OGC Energy Team Services

Clients can avail of the services of the OGC Energy team for obtaining confirmation of NACE MR0175 requirements for materials selection. Additionally, the page offers alloy-select, a web-based software designed by Oil & Gas Corrosion, to assist in materials selection for oil and gas assets.

CA6NM and F6NM Materials’ Hardness Requirements

One specific question references CA6NM and F6NM materials’ hardness requirements in accordance with NACE MR0175 part 3, clause A.6. The answer clarifies that the hardness test criteria for welding procedure qualification are specified in ISO 6507-1 or the Rockwell 15N method in accordance with ISO 6508-1 for most materials.

However, for these specific materials, there is currently no conversion from HRC to HV10 in published references, so the conversion must be agreed between the manufacturer and equipment user. The page cites ISO 15156 Maintenance Panel Inquiry #2006-01Q3 as a reference for this.