Diagnostics, Resource and Mechanics of materials and structures Issue 6, 2018 http://dream-journal.org ISSN 2410-9908 37 Hydrogen diagnostics of metals and alloys / A. M. Polyanskiy, V. A. Polyanskiy, K. P. Frolova, Yu. A. Yakovlev // Diagnostics, Resource and Mechanics of materials and structures. – 2018. – Iss. 6. – P. 37–50. – DOI: 10.17804/2410-9908.2018.6.037-050. Received: 09.06.2018 Revised: 05.09.2018 Accepted: 19.10.2018 DOI: 10.17804/2410-9908.2018.6.037-050 HYDROGEN DIAGNOSTICS OF METALS AND ALLOYS A. M. Polyanskiy 1, a) , V. A. Polyanskiy 2, 3, b)* , K. P. Frolova 2, 3, c) , and Yu. A. Yakovlev 2, 3, d) 1 RDC Electron & Beam Technology, Ltd., 6 Bronevaya St., St. Petersburg, 198188, Russian Federation 2 Peter the Great St. Petersburg Polytechnic University, 29 Politekhnicheskaya, St., St. Petersburg, 195251, Russian Federation 3 Institute for Problems in Mechanical Engineering, RAS, 61 Bolshoy Ave., V. O., St. Petersburg, 199178, Russian Federation a) https://orcid.org/0000-0002-6470-9583 ampol@electronbeamtech.com; b) https://orcid.org/0000-0002-1199-1028 vapol@mail.ru; c) https://orcid.org/0000-0003-0376-4463 kspfrolova@gmail.com; d) https://orcid.org/0000-0002-5041-0441 yura.yakovlev@gmail.com * Corresponding author. E-mail: vapol@mail.ru Address for correspondence: V. O., Bolshoy pr., 61, St. Petersburg 199178, Russian Federation Tel.: +7 921 748 06 37; fax: +7 812 321 47 71 Within the framework of this paper, we review the development of the problem of hydrogen diagnostics for metals. Metal sample enrichment techniques based on the hydro- gen vacuum extraction method had been used for a long time. The development of industrial control technologies has led to the almost complete replacement of vacuum techniques with atmospheric ones. As a result, systematic errors have occurred. These errors lead to multiple differences of certified hydrogen concentration values from measured ones for standard samples. In this paper, we analyze reasons for the genesis of systematic errors observed for hydrogen measurements while applying the thermal conductivity cell technique. As a result, we have demon- strated that measurements resulting from sample heating and melting in an inert gas flow depend on the heat capacity of the sample and the surface temperature of the melting pot. This explains multi- ple errors and even negative values in measurements of low hydrogen concentrations. Keywords: hydrogen diagnostics, hydrogen analyzer, extraction in an inert gas flow, thermal con- ductivity cell. Acknowledgment The research was supported by the RFBR, projects No. 18-08-00201, 18-31-00329 and 17-08-00783. References 1. Gesner G.W. Process of making alloys of iron and hydrogen. US Patent 670,775 , 1901. 2. Kinzel A.B. Method of casting steel ingots. US Patent 1,888, 1932. 3. Andrew T., Thomas K.B. Process of manufacturing steel. US Patent 695,264, 1902. 4. Bernhard O. Leitfaden fьr GieЯereilaboratorien, Berlin, Heidelberg, Springer, 1915. 44p. ISBN 978-3-662-40626-7. DOI: 10.1007/978-3-662-41106-3. 5. Keiichi O. On the importancy of hydrogen-brittleness as a defect in steel qualities. Tetsu-to- Hagane, 1938, vol. 24, no. 11, pp. 1005–1013. DOI: 10.2355/tetsutohagane1915.24.11_1005.