Abstract: Formation of a hybrid coating by the use of plasma nitriding and hard chromium electroplating on the surface of H11 hot work tool steel was investigated. Firstly, specimens were plasma nitrided at a temperature of 550 °C for 5 hours in an atmosphere of 25 vol. % H2: 75 vol. % N2. Secondly, electroplating was carried out in a solution containing 250 g/L chromic acid and 2.5 g/L sulp...

P. Kawulok, I. Schindler, R. Kawulok, S. Rusz, P. Opěla, J. Kliber, M. Kawuloková VSB – Technical University of Ostrava, Faculty of Metallurgy and Materials Engineering, Czech Republic Z. Solowski, K.M. Čmiel Třinecké železárny a.s., Czech republic Formability of hypereutectoid C-Mn-Cr-V steel in hot condition was investigated with use of plastometric methods. A wide range of deformation temper...

The final hot strip profile is a superposition of the roll initial crown, the roll bending and flattening crown, the roll wearing crown and the roll thermal crown. In this research, linear regression models are proposed to predict the roll force, the roll wearing crown and the roll thermal crown using experimental data provided by Mobarake Steel Complex (MSC). The short beam theory based on ela...

 In this work, effects of homogenization time of 3 to 13 h at 1200 °C on the grain refinement of as-cast AISI 301 stainless steel after different hot rolling conditions were investigated. The results showed that the minimum grain size of 16±7 mm was achieved when homogenization took place at 1200 °C for 9 h followed by hot rolling at temperature range of 1000–1200 °C with strain of 0.8 and stra...

The information about the quantitative effects of alloy elements on the hot strength of steels is scarce and contradictory. Its effects can change according to alloy content and specific conditions of the hot forming process, as they can activate different hardening or softening mechanisms. Three empirical approaches were initially adopted in this work to rank and model hot strength in steels i...

The hot compression tests were carried on X45CrNiW189 valve steel (X45) in the temperature range of 1000– 1200 °C and the strain rate range of 0.004 – 0.5 s-1 in order to study the high temperature softening behavior of this steel. For the exact prediction of flow stress, the effective stress-effective strain curves were obtained from experiments under various conditions. On the basis of experi...

The tool wear is an unavoidable phenomenon when using coated carbide tools during hard turning of hardened steels. This   work focuses on the prediction of tool wear using regression analysis and artificial neural network (ANN).The work piece taken into consideration is AISI4140 steel hardened to 47 HRC. The models are developed from the results of experiments, which are carried out based on De...