The paper presents ample researches on cavitation erosion of two charges of stainless steel type X3CrNi13-4 on a cavitation stand, through the stationary specimen method. The results of the experimental trials are highlighted in tables and in graphics regarding the reproduction of mass losses and the cavitation erosion rate according to time. The images of the microstructures before the cavitation test and the macrostructures after the cavitation test of the two charges of stainless steel type X3CrNi13-4 are also presented in this paper.

The paper presents the results of the researches regarding the determination of the thermal conductivity coefficient of the moulds used for cast iron parts in Romanian foundries. The instantaneous values of the thermal conductivity coefficient of the moulds are influenced by the type of materials that compose the moulding batch (sand, binder, additional materials) their content (percentage) their characteristics (grains form and dimensions), but also by the temperature. Many software used for casting solidification uses a mean substitutive value. This one include the effect of heat transmission by conduction in the mould wall and the secondary processes that influence the heat transfer throw the mould wall ( burning processes of organic substances, water evaporation and re-condensation processes, mass transport processes). The determination of this mean value in the case of casting grey cast iron parts with thickness of 20 mm is presented in the paper. A regressive method was applied. The solidification time experimentally determined throw thermal analyses is compared with the solidification time obtained by simulation, in three points of the casting. The value of the substitutive coefficient of thermal conductivity that assure the best closeness between the simulated solidification time and the solidification time experimentally determined throw thermal analysis in the three points was established.

This paper presents a comparative analysis between the practical results of pig iron die-type part casting and the results reached by simulation. The insert was made of polystyrene, and the casting was downward vertical. As after the part casting and heat treatment cracks were observed in the part, it became necessary to locate and identify these fissures and to establish some measures for eliminating the casting defects and for locating them. The research method was the comparisons of defects identified through verifications, measurements, and metallographic analyses applied to the cast part with the results of some criteria specific to simulation after simulating the casting process. In order to verify the compatibility between reality and simulation, we then simulated the part casting respecting the real conditions in which it was cast. By visualising certain sections of the cast part during solidification, relevant details occur about the possible evolution of defects. The simulation software was AnyCasting, the measurements were done through nondestructive methods.

The exploitation durability of Kaplan hydraulic turbines blades is first of all determined by their structure, by the steel elaboration technology, respectively by the content of non-metallic inclusions and later by the physical-chemical parameters of the exploitation environment.This paper presents a study regarding the situations in which the elaboration-casting technology of Kaplan blades using alloyed austenitic stainless steel, X5CrNiMo17-13-3 which has an important role in the quality of castings. Thus, the authors verify the formation of sulfides and of oxi-sufides during the steel elaboration process, treatment during a liquid state and their influence in the castings behavior to wearing. It is a well known fact that the presence of sulfides and oxi-sufides in the cast blades structure accelerates the corrosion process in contact with river waters.

This paper presents the study of experimental researches on cavitation erosion behavior of some bronzes with varying percentages of Sn and Pb. These experimental researches were made in „Eftimie Murgu” University of Resita laboratories for three different alloys, namely CuSn5Pb20, CuSn8Pb15 and CuSn10Pb5. After rehabilitation of certain equipment that was operating with running water, some pieces made of bronzes, were replaced and there were taken samples for studying which were analyzed in order to identify the causes that led to their wear. Finally, these materials were compared, after the obtained results regarding the cavitation erosion resistance and after the metallographic analysis.