METHOD OF TESTING STEEL UNDER ACTION OF HYDROGEN Russian patent published in 2025 - IPC G01N17/00 

FIELD: measuring.

SUBSTANCE: invention relates to testing of materials, namely to methods of cyclic corrosion-mechanical tests of pipe steels under action of gaseous hydrogen or hydrogen-containing gas mixture. Method of testing steel under action of hydrogen consists in the fact that rectangular specimen with rounded side faces on external surface is cut from wall of defect-free section of main gas pipeline. It is prepared for testing, during which the sample is subjected to cyclic loading in air and at constant contact of the external surface of the sample with a corrosive solution. Tests are carried out before initiation of cracks in the working part of the specimen. Then the sample is cooled in liquid nitrogen, destroyed by impact action, the value of increment of the formed cracks in length and depth of the sample is measured. Their ratio to the number of applied loading cycles is used to determine the rate of crack growth in air and with a corrosive solution. At least one through hole is drilled in the sample equidistant from the central part along the cross-section centre on both sides symmetrically and equidistant from the central part, in the cavity of which on each side of the sample there are inserted nozzles, which are equipped with gas supply branch pipes, gas shutoff and measuring valves, through which hydrogen-containing gas mixture is supplied to through holes of the sample under constant pressure, which is maintained until the end of tests.

EFFECT: high accuracy of measuring crack growth rate and reliability of predicting crack resistance of steel pipes in conditions close to real ones.

5 cl, 2 dwg