Nace Rp0472 Pdf !exclusive! -

Certain welding processes like SMAW with E60XX/E70XX or GTAW with specific ER70S fillers may be exempt from production hardness testing under specific conditions. How to Access the PDF NACE Standard RP0472-2005 - ANSI Webstore

: Keeping hardness below this limit ensures that the microstructure (primarily avoiding untempered martensite) is ductile enough to withstand the "pressure" of hydrogen atoms migrating into the metal lattice. 3. Critical Prevention Strategies