Thermal Conductivity and Thermal Diffusivity Coefficients of 12Kh18N10T Stainless Steel in a Wide Temperature Range

摘要

High-alloy austenitic 12KM8N10T (chrome-nickel-titanium) steel (GOST [State Standard] 5632-72) exhibits a complex of properties which enable one to use this steel as the structural material for vacuum systems, corrosion-resistant, cold-resistant, heat-resistant, and other articles. Data on the coefficients of thermal conductivity X and thermal diffusivity a are required for the calculation of thermal stresses in articles and of thermal fields. Precise and reliable data on X at temperatures below 300 K are given in [1]. The majority of reference books in the range of high temperatures employ data identical to those of [2], for which no error was determined. Measuring the thermal conductivity coefficient in the high-temperature range is a complicated problem, because it is difficult to correctly include the heat transfer between sample and environment. In this situation, instead of measuring X, this coefficient may be found by the results of measurements of thermal diffusivity of the material (for which no measurements of heat fluxes are required) and by the data on heat capacity C{sub}p and density p, using the relation λ = aρC{sub}p. (1) As a rule, the data on C{sub}p and p are much more precise than those on thermal diffusivity; therefore, the error of determination of λ almost coincides with that for a.