Hydrogen Diagnostics of Metals and Alloys

Abstract

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 hydr ogen 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 te chniques 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 demonstrated 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 multiple errors and even negative values in measurements of low hydrogen concentrations.

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