NACE RP0472, redesignated as NACE SP0472 and currently in its 2020 version, establishes essential guidelines for controlling carbon steel weldment hardness to prevent environmental cracking in petroleum refining environments. The standard dictates specific practices, such as a 200 Brinell hardness limit, to prevent cracking mechanisms like sulfide stress cracking and alkaline stress corrosion cracking. Purchase the official standard at the AMPP Store.

NACE SP0472 (formerly RP0472) provides the industry-standard "Methods and Controls to Prevent In-Service Environmental Cracking of Carbon Steel Weldments." Key Takeaways for Engineers & Inspectors: Target Hardness:

Option 3: Engineering Association Membership

Are you an ASME or API member? Your library might have a reciprocal agreement with AMPP. Check your member portal for "Standards Access."

Title: 🛡️ NACE SP0472: Preventing Weld Cracking in Sour Service Environments

• The 1972 version (obsolete and dangerous).
• A Chinese or Japanese translation without the hardness tables.
• Scanned, unsearchable, and missing the critical flowchart.

Why Do You Need NACE RP0472?

In wet H₂S environments, even "correct" carbon steel can fail catastrophically if the welding process introduces hard spots, excessive residual stress, or improper heat treatment. RP0472 provides the practical, step-by-step controls to mitigate these risks.