THERMOPHYSICAL PROPERTIES OF SELECTED BARREL STEELS

Abstract

This paper is devoted to the study of thermo-physical properties, i.e. thermal diffusivity, thermal conductivity, thermal expansion and specific heat of selected barrel steels. In typical barrel steels, e.g.30HN2MFA, a structural transformation occurs at about 730 , at which material shrinkage occurs. The way to increase the durability of the barrels is to change the steel grade to one in which this transformation does not occur or does occur, but at higher temperatures. The paper presents the results of experimental studies of all the above-mentioned thermophysical properties of five selected barrel steels, i.e. 38HMJ, 30HN2MFA, DUPLEX 2205, WCL and MARAGING 350. Measurements were made in the range from room temperature to about 1100 C. In this way, a database of thermo-physical properties of these steels was created as input data for the calculation of heat transfer in the barrels of small arms and cannons.