If Carburizing is not considered the same as Nitriding in paragraph A. 2.1.5, is it acceptable to have carburized surface treatment (where the surface hardness will be well over HRC 22 hardness) but the core to meet the maximum average hardness of 22 HRC?
Carburizing is not permitted regardless of core hardness except as noted in Q1.
This question is in relation to NACE MR0175/ISO 15156-3 Annex A.1.5.1
Reference: ISO 15156 Maintenance Panel Inquiry #2013-04Q2