This paper presents a test method for the evaluation of carbon steels for resistance to stIess oriented hydrogen induced cracking (SOHIC). It involves the extension of standard non-stressed HIC tests per NACE TM0284 to incorporate the following aspects critical for the evaluation of steels for wet H2S equipment: (1) application of tensile stress, (2) full immersion and one-side exposure, (3) evaluation of welded and non-welded specimens, and (4) crack location coding. A double beam (DB) test specimen adapted from ASTM G-39 loaded in 4-point bending is utilized to provide an applied stress. In addition to conventional analyses for internal cracking per NACE TM0284, analysis were developed for (1) crack location coding relative to weld, HAZ and base metal locations and for position of cracks relative to tension surface or centerline locations, and for (2) a simplified some evaluation procedure involving the measurement of SOHIC crack extension in a notch, non-welded specimen. Data is presented which highlights these particular aspects of the DB test specimen relative to other standard test specimens per NACE TM0177 and TM0284 and for a round robin testing program using the DB specimen.
Keywords: stress oriented hydrogen induced cracking, hydrogen induced cracking, sohic, HIC, hydrogen sulfide, test method, specimen, round robin test program, petroleum, plate steels, double beam test, TM0177, TM0284.