Ewa Kasprzycka DIFFUSION LAYERS PRODUCED ON IRON AND STEEL SURFACE IN CHROMIUM CHLORIDE ATMOSPHERE AT LOW PRESSURE Chemical vapor deposition of chromium on the surface of iron and low-carbon steel has been investigated using a novel method that combines the low cost of pack cementation method with advantages of vacuum technique. <...> The processes have been performed in chromium chlorides atmosphere at a low pressure range from 1 to 800 hPa, the treatment temperature 800 to 950oC. <...> The effect of the vacuum level during the process and the process parameters such as time and temperature on the growth kinetics of diffusion layer on steel surface has been investigated. <...> The investigations have proved that the chromizing process under low pressure, with static vacuum instead of dynamic vacuum conditions during the holding is the most effective as far as the growth kinetics of diffusion layers is concerned. 1. <...> INTRODUCTION Diffusion chromizing is a thermochemical treatment employed today for improving properties of steel surface such as corrosion resistance and wear [1ч6]. <...> Chromized layers of that structure can be obtained only on the pure iron and on special low-carbon steels stabilized by means of strong carbidizing elements (Ti, Nb, V) binding the carbon in steel as the stable carbides [1]. <...> The diffusion chromizing consists in holding steel at the temperature over 800oC in chromium compounds (e.g. chlorides) atmosphere. <...> Chromium is transferred to the steel surface by one or more of several possible deposition reaction (of interchange, of reduction, or of thermal dissociation types) and then it diffuses in it to create a layer. <...> In this paper, a novel method that combines the low cost of pack metallization and the advantage of vacuum technique was investigated [7]. <...> The proposed method was obtained by means of heating a batch in a dynamic vacuum and then holding it in a static vacuum [6, 7]. <...> However, in such conditions, also reactive vapours e.g. chromium chlorides, necessary to produce a layer, are taken away, and consequently, chromizing process. <...> The objective of this paper was to determine the effect of the vacuum level during the process and the process parameters such as time and temperature on layer diffusion growth on iron and low carbon steel surface. 2. <...> The oven construction makes it possible <...>