4.1 Hard-drawn steel wire as used in prestressed concrete pipe may be exposed to elemental hydrogen favorable to hydrogen induced embrittlement and cracking. Resistance to hydrogen embrittlement is necessary for prestressing wire to provide long-term performance to installed pipe.

4.2 The length of time that a stressed wire specimen resists failure while exposed to a heated solution of NH₄SCN, is an indication of the specimen's resistance to hydrogen embrittlement.

1.1 This test method describes procedures to determine the hydrogen embrittlement (HE) resistance of hard-drawn steel wire used for prestressed concrete pipe.

1.2 HE resistance is reported as time-to-failure of specimens tested in a laboratory.

1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.

1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.