NACE hardness testing specifications

[CWEng]

Do NACE MR0175 and MR0103 call out the correct hardness testing standards? NACE MR0175-2015 says to use ASTM E384, and NACE MR0103 says ASTM E92 has been replaced by ASTM E384. Yet both ASTM E92-17 and ASTM E384-17 appear to be active. ASTM E384 is only for microhardness up to 1000g, and E92 is for Vickers hardness testing over 1kg. Since NACE specifies hardness testing at either 5kg or 10kg, it seems like they are calling out the wrong standard? Am I missing something, or did ASTM not do something NACE was expecting with regards to standard replacement?

 

[SJones]

MR0175 calls up ISO 6507-1 whose scope includes microhardness testing, hence the note under 7.3.3.2, and confirmation by Inquiry #2006-08 in the Inquiries & Interpretations.

https://isotc.iso.org/livelink/live...c=ll&objId=3340364&objAction=browse&sort=name

There would appear to be a definite error in Annex C, C.1 of ISO 17945/MR0103, since the required forces are outside of the scope of the referenced test standard.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[CWEng]

Thanks Steve. I was paraphrasing a bit in my initial post since I didn't have the specs in front of me at that time, but looking at MR0175, it says in 7.3.3.2 "Note: For the purposes of this provision, ASTM E384 is equivalent to ISO 6507-1..." In my case, we need to use ASTM E92, as the labs we have used have ISO 17025 certification (per our customer requirement) to E92, but not ISO 6507-1. But NACE says E384 is equivalent, even though microhardness testing is not being done.

 

[SJones]

Just convince the customer that E92 is also technically equivalent to ISO 6507-1. E384 is, effectively, a supplement of E92.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.