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The paper deals with a modeling of laminate plates and with their buckling analysis. To predict the inception of buckling for plates in plane resultant forces must be included. The buckling analysis is made by the help of finite element method in program COSMOS/M. For rectangular laminate plate consisting of 4 layers with symmetric and antisymmetric stacking sequence a buckling analysis is carried out. In the illustrative example there are depicted buckling modes for symmetric laminates [30/-30]s, [45/-45]s, [60/-60]s, [90/-90]s and results of the buckling analysis for the symmetric and antisymmetric laminates.

The peculiarities of the morphology and structure defects of composite material in the Cu-Mo-Zr-Y system produced from commercially pure raw materials using method of electron-beam evaporation/condensation have been studied. The features of deformation and destruction of the composite have been investigated alongside with its mechanical properties and their change under action of structure defects.

The paper analyzes the influence of the impact rate of up to 120 ms-1 with a constant energy on the relative compression of high-grade unalloyed steels, Cu and Zn, and the evaluation of energy consumed during the impact bending test at the impact rate of up to 80 ms-1. Based on the experiments made, relationships for the prediction of the influence of the strain rate within the range of 10-3 – 2.5.103 s-1 on the mechanical properties of high-grade unalloyed steels with the yield point of 210 – 450 MPa and microalloyed steels with the yield point of 300 – 600 MPa are presented.

The Udimet 500 nickel base superalloy blade exposed for 50000 hours in land base gas turbine working conditions faced the structure degradation. Six different heat treatments procedures have been applied (the blades were exposed at 900 °C and 1000 °C for different periods with maximum hold of 2500 hours) to rejuvenate the degraded structure. Metallographic work was performed, generally, aging at both temperatures modify the gamma prime size, morphology and distribution characteristics substantially. The volume fraction of secondary gamma prime decreased with increasing aging time.

The main tendency towards the development of the methods for predicting long-time data on of metallic materials is to derive the correlation relationships, which should be as general as possible. This paper presents the verification of the fact that a sufficiently accurate estimation of the peculiarities of the portions of experimental diagrams and generalization of this information can be of great importance for a considerable progress in the prediction.

Da bi opstao i zadržao prednost izradbe bešavnih cijevi u odnosu na suvremene valjaonice, kod pilger postupka treba povećati produktivnost, smanjiti troškove prerade i posebice poboljšati kakvoću i površinu cijevi. U članku se daje mogućnost modernizacije pilger stana (pogona, kućišta, posmaka cijevnice, itd.).

The annealing temperature within the range of 1223 - 2273 K has been studied for its effect on the grain size, mechanical properties, cold brittleness temperature, and nature of failure of sheets molybdenum alloys TsM-6 and TsM-10. The method of Auger-electron microscopy has been used to study the change of carbon and oxygen content on grain boundaries of the alloy TsM-10 and the change of mechanical properties associated with it as dependent on the annealing temperature.

The paper analyses the material characteristics of deep-drawability of steel sheets with the thickness from 1 to 1,8 mm, the yield point above 330 MPa and the loading rate up to 150 m/min. The analysis resulted in the finding that with the loading rate up to ca 10 m/min the formability characteristics slightly increase and after exceeding this value these characteristics significantly decrease. In practice, the strain rates are below 1 s–1, therefore the material characteristics determined using standard tests can be used to determine the limit states up to the above-mentioned rate.

The paper analyzes the fatigues properties of galvanized microalloyed steel sheets H220LAD and H380LAD. Under flat bending conditions and the symmetrical cycle, the fatigue limit of the H220LAD sheet is σCo = ± 152 MPa and that of the H380LAD sheet is σCo = ±188 MPa, and the fatigue limit to tensile strength ratio is 0,41 and 0,37, respectively. During fatigue tests with an increasing number of cycles or an increasing stress value, the degradation of the zinc coating increases (relief formation, damage of integrity). As a result, local corrosion, but also continuation of fatigue damage after 107 cycles, and hence corrosion fatigue, can take place during operation.

At the first look very simple and for several hundred years used elastic element can be critical part in complex equipment where its failure invokes extraordinary high losses. In the paper is given a treatment for the solution of this problem by experimental methods and resulting proposal for its final solution.

Low carbon steel AISI 10 was subjected to a severe plastic deformation technique called Equal Angular Channel Pressing (ECAP) at different increased temperatures. The steel was subjected to ECAP with channel’s angle j = 90°, at different temperature in range of 150 - 300 °C. The number of passes at each temperature was N = 3. Light, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) of thin foils were used to study the formation of substructure and ultrafine grains in deformed specimens. The size of newly born polygonized grains (subgrains and/or submicrocrystalline grains) is in range of 300 - 500 mm. The formation of such of predominant submicrocrystalline structure resulted in significant increase of yield stress [Re] and tensile strength of the steel [Rm].

The production of Cu-Zr-Y-Mo Finely-Dispersed (FD) microlayer composite materials for electrical contacts by the method of electron-beam evaporation and layer-by-layer condensation from the vapor phase is described and the chemical composition, structure, density, electrical conductivity, hardness, and main mechanical characteristics of the materials in the temperature range from 290 to 1070 K are studied.

The paper analyzes the influence of the loading rate in the interval from 1 to 1000 mm/min on the mechanical properties of drawing steel sheet H260LAD with the gauge of 1 mm, used for the manufacture of automotive parts, under tension and bending conditions. It describes the aspects of material characteristics under tension and bending conditions, while bending tests were made on notched specimens (a modified impact bending test). The paper presents knowledge that using a modified notch toughness test it is possible to achieve the pressability (formability) characteristics corresponding to dynamic strain rates even under the static loading.

Using the solution of a closed problem of the theory of plasticity some analytic expressions were obtained for determination of the strain parameters of zone of deformation in view of the temperature factor.

The influence of technological factors and constructive parameters of the cold pilger rolling mill to the warm conditions of deformation is observed. The dependences of the heat conditions of pilger rolling on deformation mode and preheating temperature are shown. There was a conclusion drawn about the expediency of combination of warming and cooling of the metal for keeping the deformation zone temperature within limit, which corresponds to the minimal intensity of the metal strengthening.

The paper considers dependencies of metal forming characteristics on dimensionless geometrical parameters of flat pocket die design at direct extrusion of aluminium thin-walled solid profiles. The theoretical analysis of plastic metal flow is carried out by means of the 2 -D FEM model. The new method for flat pocket die design is proposed in the paper. The die design example is given for non -symmetrical U-shape profile.

The paper deals with the classification of steel sheets for automotives industry on the basis of strength and structural characteristics. Experimental works were aimed to obtain the best possible strengthening parameters as well as work hardening and solid solution ferrite hardening, which are the result of thermal activation of interstitial carbon atoms during paint-baking of auto body. Hardening process coming from interstitial atoms is realized as two-step process. The first step is BH (bake hardening) effect achieved by interaction of interstitial atoms with dislocations. The Cottrels atmosphere is obtained. The second step of BH effect is to produced the hardening from precipitation of the carbon atoms in e-carbides, or formation of Fe32C4 carbides. WH (work hardening) effect is obtained as dislocation hardening from plastic deformations during sheet deep drawing. Experimental works were aimed at as to achieve such plastic material properties after cold rolling, annealing and skin-pass rolling, which would be able to classify the material ZStE220BH into the drawing categories at the level of DQ – DDQ. As resulting from the experimental results, the optimal treatment conditions for the maximal sum (WH+BH) = 86 MPa are as follows: total cold rolling deformation ecold = 65 %, annealing temperature Tanneal. = 700 °C.

The aim of this paper is to consider the features of structure evolution during severe plastic deformation (SPD) of steels and its influence on mechanical properties. The investigation have been carried out mainly on low carbon steels as well as on austenitic stainless steels after SPD by torsion under high pressure (HPT) and equal channel angular (ECA) pressing. Structure formation dependencies on temperature deformation conditions, strain degree, chemical composition, initial state and pressure are considered. The role of phase transformations for additional grain refinement, namely, martensitic transformation, precipitation of carbide particles during SPD and heating is underlined.

In the last decade, a lot of effort has been paid to optimising the thermomechanical processing of TRIP steels that stands for transformation induced plasticity. The precise characterization of the resulting multiphase microstructure of low alloyed TRIP steels is of great importance for the interpretation and optimisation of their mechanical properties. The results obtained in situ neutron diffraction laboratory experiment concerning the austenite to ferrite transformation in Si-Mn bulk TRIP steel specimens, displaying the transformation induced plasticity (TRIP), are presented. The advancement of ferrite formation during transformation in conditioned austenite is investigated at different transformation temperatures and has been monitored using neutron diffraction method. The relevant information on transformation proceeding is extracted from neutron diffraction spectra. The integrated intensities of austenite and ferrite neutron diffraction profiles developed during the transformation are then assumed as a measure of the phase volume fractions of both phases in dependence on transformation temperature and austenite conditioning. According to the yielding information on ferrite volume fractions from isothermal transformation kinetics data the thermo mechanical processing of bulk specimen was designed in order to support austenite stabilization through bainitic transformation. The volume fractions of retained austenite resulting at alternating transformation conditions were measured by neutron and X-ray diffraction respectively. The stability of retained austenite in bulk specimens during room temperature mechanical testing was characterized by in situ neutron diffraction experiments as well.

The authors studied the characteristics of strength of filtering composite materials reinforced by a two-layer nickel mesh with a coating depending on the cutting-out angle. The anisotropy of the characteristics of strength is shown to be the closest to the Ashkenazy phenomenological strength criterion in the form of a fourth degree polynomial, which describes the ultimate strength vs net cut-out angle limiting curve.

Investigation results indicating the influence of high-density impulse electric current on impact toughness of Charpy specimens manufactured from low carbon steel are presented. It is shown, that impulse electric current treatment causes a considerable growth of impact toughness of the steel, and type of material fracture is changed from brittle mode to ductile mode.

This document is a supplement to the "Book of Abstracts" for the 17th Symposium on Materials and Metallurgy. It includes summaries of various research studies related to materials and metallurgy. The topics covered include the fatigue life of automobile bellows, the feasibility of power flexible cable production, real-time detection of green pellets, design of an automatic opening and closing manipulator for ore crushing ball mill cover, formation of slag inclusions in billets during casting, use of amorphous alloys to strengthen pipe tools, research on heat engineering processes of secondary metallurgy, efficient recovery of cobalt from spent lithium-ion batteries, influence of process parameters on grain structure in vertical continuous casting, finite element analysis of connecting shafts in cold rolling mills, effect of acid-soluble aluminum content on precipitates and magnetic properties of grain-oriented silicon steel, selection and priming of technological solutions for refining manganese-based alloys, oxidative conversion of methane on freshly reduced iron, constitutive model of high temperature plastic deformation of P91 alloy steel, steel filtration using multi-hole ceramic filters with an innovative design, and the constitutive model of high temperature plastic deformation of TC17 titanium alloy for underwater robot metal material. [Extracted from the article]