Hydrogen failure sensitivity of A516-Gr70 and API 5L-X70 steels in sour environments

作者：Taheri H; Dolati A; Beidokhti Behrooz^*

来源：ANTI-CORROSION METHODS AND MATERIALS, 2015, 62(5): 294-300.

DOI：10.1108/ACMM-01-2014-1340

• Corrosion
• Pipelines
• Hydrogen sulphide
• Polarization
• Steel

Purpose - This paper aims to clarify the corrosion behavior of two famous structural steels in sour environment. These steels have a vast application in oil and gas industries. The study aims to find the effect of different concentrations of sour solution on the origin of crack in these steels.
Design/methodology/approach - After preparation of specimens, different sour solutions were made using the synthetic brine (according to National Association of Corrosion Engineers [NACE], Technical Committee Report 1D182) and various amounts of Na2S center dot 9H(2)O and CH3COOH. The polarization test was done by Potansiostat apparatus model Zahner-IM6 at two temperatures, 25 degrees C and 50 degrees C. The corrosion current densities were obtained from the polarization curves. Finally, the corrosion products and hydrogen-induced cracking (HIC) were investigated by Tescan Vega II XMU scanning electron microscope (SEM) linked to a Rontec energy-dispersive X-ray spectroscopy (EDS) system.
Findings - API 5L-X70 steel showed smaller corrosion current values than A516-Gr70 steel. The HIC cracks propagated parallel to the surface of A516-Gr70 steel in three solutions and confirmed the inappropriateness of this steel for sour environment applications.
Originality/value - This paper studies the effect of sour environment on the behavior of two famous industrial steels at two temperatures by new method.

• 出版日期2015