scope:

General

This standard establishes a test method for evaluating the resistance of pipeline and pressure vessel plate steels to HIC caused by hydrogen absorption from aqueous sulfide corrosion.

Special procedures or requirements for testing small-diameter (nominal pipe size [NPS] ² through 6), thin-wall (up to 6-mm wall thickness), electricresistance welded (ERW) and seamless line pipe are included. These small-diameter, thin-wall materials shall be tested in the same manner as other line pipe except as otherwise stated in this standard. 

The test method consists of exposing unstressed test specimens to one of the two standard test solutions-either Solution A, a sodium chloride, acetic acid (NaCl, CH3COOH) solution saturated with H₂S at ambient temperature and pressure, or Solution B, a synthetic seawater solution saturated with H₂S at ambient temperature and pressure. After a specified time the test specimens shall be removed and evaluated.

The test method is not intended to duplicate service conditions. It is intended to provide reproducible test environments capable of distinguishing the susceptibility of different steel samples to HIC in a relatively short time. NOTE: The length of the test may not be sufficient to develop maximum cracking in any given steel but has been found to be adequate for the purpose of this test.

This standard does not include acceptance or rejection criteria. The methods used for determining acceptance and rejection, for comparing different steels, for screening of steels, or for other purposes are beyond the scope of this standard.