Abstract: A steel alloy for use as a material for storage tubes adapted to receive pressed objects of metal powder, which can store hydrogen and release the same, is of the composition comprised of 0.14 to 0.18 weight percent of carbon material 0.15 to 0.3 weight percent of silicon, maximum 0.025 weight percent of phosphorus, maximum 0.025 weight percent of sulfur, from 1.9 to 2.1 weight percent of chrome, from 0.45 to 0.60 weight percent of molybdenum, at least 0.015 to 0.030 weight percent of aluminum, and iron.

Abstract: A process for the optimized heat transfer from carriers of reversible, heterogeneous evaporation processes for the purpose of generating heat and cold by means of the principle of the heat pipe is described, which comprises arranging the carrier of the reversible, heterogeneous evaporation process in the interior of a heat pipe. Moreover, this application describes the apparatus for carrying out the process in which a heat pipe is provided with a heat source at the bottom and with a heat sink at the top and exhibits a carrier of a reversible, heterogeneous evaporation process and a feed line and discharge line for the gas of the reversible, heterogeneous evaporation process.