Ewa Kasprzycka DIFFUSION CARBIDE LAYERS PRODUCED ON TOOL STEEL SURFACE IN VACUUM TITANIZING PROCESS Diffusion carbide layers produced on tool steel surface by means of vacuum titanizing process have been investigated. <...> Studies of layers thickness, their morphology, Ti, Cr, C and Fe concentration depth profiles in diffusion zone of titanized layers have been carried out. <...> Tribological properties and corrosion resistance of titanized carbide layers have been determined. <...> INTRODUCTION Diffusion titanizing is one of many types of thermochemical treatment used mainly to improve the hardness and wear resistance of steel surfaces. <...> Titanizing of tool steel results in hard and wear resistant coatings based on titanium carbide. <...> There is considerable bibliographical data concerning the diffusion titanizing process, in particular, problems connected with hard titanium carbide layers are quite well elaborated [1–3]. <...> In the Institute of Precision Mechanics vacuum titanizing method was developed, which consists in holding steel at the temperature over 1000°C in titanium vapour under low pressure conditions [4]. <...> The objective of this paper is to determine the microstructure, tribological corrosion resistance of carbide layers produced on tool steel surface during process. 2. <...> EXPERIMENTAL DETAILS Experiments were carried out on polished samples made of NC10 tool steel (according to the Polish Standard) containing 1,8 % C and 12,0 % Cr. <...> Titanized of this steel samples was carried out in a cold wall vacuum furnace at the temperature range of 1050 – 1100°C at the pressure ranged from 10 Pa down to 10-3 Pa using the novel method [5]. <...> Metallographic examinations and thickness measurements of titanized layers were carried out with an optical microscope. <...> Layer microstructure was revealed by nital etching. <...> Tribological properties of the titanized carbide layers were evaluated by sliding wear tests with 126 Проблемы машиностроения и автоматизации, № 1 – 2007 properties and vacuum titanizing concentrated contact. <...> Wear tests were performed on sets of taper-three rolls testpieces at constant surface pressure in the range 50–300 MPa. <...> Corrosion measurements have been performed by means of electrochemical in 0.1 M <...>