KINETIC CHARACTERISTICS AND FEATURES OF PRINCIPLE OF WIEDEMANN--FRANZ MARAGING STEEL Fe--Ni--Al--Ti IN VARIOUS PHASE-STRUCTURE STATES

摘要

The temperature dependence of kinetic characteristics (such as electrical conductivity, thermal conductivity and coefficient of thermoelectromotive force) of maraging steel on the iron-nickel base of the Fe-Ni-Al-Ti system (N26YT2B) in martensite-austenite states in the temperature range of 4.2-1173 K is investigated. The Lorentz factor is calculated on the basis of the experimental data and its sensitivity to phase-structure transformations was analysed in such a class of alloys. It was found out that titanium in comparison whith aluminium exerts a predominant influence on such alloys as regards their electronic structure, crystal-structural states at various temperatures and the corresponding values of electrophysical and thermal characteristics. It appears that low-temperature dependences of Lorentz factor from the phase-structure state of the maraging steel shows of the temperature of 4.2-200 K not only the maximum but also the minimum. The data about a set of 16 physical and mechanical properties of the alloy in two most typical phase-structure states formed by thermal treatments is given. The tested alloy with its thermo-physical properties can successfully compete with classic cryogenic materials for all that with its unique adaptability to manufacture.