Does NACE MR0175 allow additional heat treatment for stress relief of CA6NM and F6NM?
I have a question regarding NACE MR0175/ISO 15156-3. On Table A.18, the heat treatment requirements for CA6NM and F6NM are listed. Is this the only approved heat treatment? If we follow this heat treatment initially, are other heat treatments allowed as long as they do not exceed the original? We’re trying to find out if a supplemental stress relieve is acceptable to try and lower the material hardness.
Only the heat treatments listed are currently acceptable. Other heat treatments may be qualified in accordance with the requirements of NACE MR0175/ISO 15156-3 Annex B.
This question is in relation to NACE MR0175/ISO 15156-3 A.6.2. Table A.18
Reference: ISO 15156 Maintenance Panel Inquiry #2006-19