Clarifying PWHT Requirements for Carbon, Carbon-Manganese, and Low Alloy Steels

This webpage features a question regarding the confusion surrounding post-weld heat treatment (PWHT) requirements for as-welded carbon steel, carbon-manganese steel, or low alloy steel that meets the hardness requirements of Table A.1 with only HRC hardness testing.

PWHT Requirements for HRC Hardness Testing

The answer clarifies that for carbon, carbon-manganese, and low alloy steels, PWHT must be performed for hardness testing via the HRC method only if the design stress exceeds 2/3 SMYS.

Alternative Hardness Testing Methods

However, if hardness testing is performed via the HV or HR15N methods as specified in 7.3.3.2, the restrictions for design stress and PWHT are not required.

Reference and Contact Information

This question pertains to NACE MR0175/ISO 15156-2 Clause 7.3.3.2. For assistance with NACE MR0175 requirements and your welding procedure qualification, you can contact us. We are ready to help you.