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U članku je dan prikaz programa djelatnosti Hrvatskog metalurškog društva (HMD) za 2023. godinu.

Cilj rada je dati osvrt u budućoj Monografiji „Obljetnice Hrvatske metalurgije“: - Utemeljenje i razvitak Hrvatskog metalurškog društva (HMD-a) iz Društva inženjera i tehničara Željezare Sisak, Sisak (DITŽS / 1952.-2022.), uz postignuća i aktivnosti. - Razvoj metalurgije u svijetu čiji počeci datiraju u 7 tisućljeće pr.k., te 6000 godina metalurgije na tlu današnje Hrvatske: Vučedolska, Keltska, Rimska i poslije dolazak Hrvata. Povijest metalurgije u Hrvatskoj, te postignuća i kolaps (1990. – 2012.). Ima više tiskovnih priopćenja javnosti u cilju opstanka i revitalizacije Hrvatske metalurgije (X Privitaka). - Šezdeset godina od utemeljenja i razvitka Sveučilišnog studija metalurgije u Sisku (1960. -2020.). Od Metalurškog odjela Tehnološkog fakulteta Sisak, reorganizacija 1974., 1979., 1991., i samostalnog Metalurškog fakulteta (MF) uz rezultate i poteškoće tijekom 60 godina, daju se citati radova autora o MF-u, a dio citiranih radova i kao cjeloviti tekstovi (XV Privitaka). - Šezdeset godina tiska časopisa Metalurgija 1962. – 2022. sa 199 svezaka (238 brojeva), objavljeno 2721 znanstvenih (i stručnih radova), 287 priloga – ukupno 3008 radova od 3575 autora / koautora. Posebice i objavljeno sa 14 simpozija Hrvatskog metalurškog društva „Materijali i metalurgija“ (14 Uredničkih knjiga) „Zbirka sažetaka“ – sa 6009 sažetaka i cca 10 000 autora / koautora – Bibliografija 1962. – 2022., The goal of this work is to give an overview in future tense Monograph „Anniversaries of Croatian Metallurgy“: - The Foundation and Development of Croatian Metallurgical Society (CMS) from the Society of Engineers and Technicians of Steelwork Sisak (SETSS /1952-2022), with achievements and activities - The Development of metallurgy in the world whose beginnings date 7 000 years also 6 000 y metallurgy on the territory of today Croatia: Vučedol, Celtic and Roman, after with the arrival of Croatia to this territory. History of metallurgy, achievements and the destructions (1990-2012). It have also several press notices to the public information in order to sustain and revitalize the Croatian metallurgy (X Supplements) - Sixty years of the Foundation and Development of University studies of metallurgy in Sisak (1960-2020). From Metallurgical Dep. of Technological Faculty Zagreb, reorganizations in 1974, 1979, 1991 y till status of Metallurgical Faculty (MF) with incorporation in University of Zagreb. By results and difficulties during 60 years, gave citations Author´s works about MF, and parts of them also as whole texts (XV Supplements). - Sixty years of the publishing of the Metalurgija Journal (1962 – 2022), with print: 199 issues (238 Numbers), published 2721 Scientific (and Technical) papers, 287 contributions, a total of 3008 works, from 3575 Authors and Co-authors. Separately published from 14 Symposiums „Materials and metallurgy“ of Croatian Metallurgical Society (14 Editorial Books), „Book of Abstracts“ – 6009 Abstracts from approx. 10 000 Authors / Coauthors – Bibliography 1962-2022.

The paper deals with structure and properties development of AHSS (advance high-strength steel) and UHSS (ultra high-strength steel) steel grades for various groups of automotive parts. C-Mn-Si type steel properties are evaluated based on the results of laboratory controlled rolling and cooling. The important influence on mechanical and plastic properties, amount of residual austenite (RA) and final structural type has, except for cooling rate, also starting temperature of intensive cooling (TIC) which follows after hot plastic deformations. If TIC is from interval of 620- 760°C the final structure predominantly consists of ferrite with RA. Mostly acicular ferrite with RA, as well as bainite with RA was obtained when TIC was kept in the range of 760-850°C.

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 contribution deals with the evaluation of wear resistance three types thermally sprayed coatings deposited by HVOF spraying. The wear resistance of these coatings was evaluated by simulation of erosive wear. Erosive wear was simulated by abrasive blast cleaning process using abrasive - brown corundum. Simultaneously there was studied influence of various impact angles on wear resistance of HVOF coatings. Study of properties the coatings was supplied also by measuring thickness, adhesion, microhardness and by EDX analysis. Construction and structure of coatings were studied using optical and electron microscopy. The research results showed that all coatings exhibit comparable resistance against erosive wear, greater weight loss was observed at impact angle 75°. v Adhesion of coatings after heat load slightly decreased, but within 10 thermal cycles stayed relatively stable. Despite these results, it is not possible to recommend to the operational conditions with high and fluctuating temperature neither coating WC-Co-Cr by reason of its thermal cracking nor WC-17Co coating for its strong oxidation during thermal cyclic loading. The best properties in conditions of high temperature showed coating Cr3C2-25NiCr.

The authors conducted an investigation into changes in the structure, electrical conductivity and mechanical properties of a copper-tungsten composite, depending on the content of tungsten. The composite is obtained by the electron beam physical vapour deposition (EB-PVD) technique. New morphological peculiarities of the condensed composite that cause changes in the material properties are found. The conditions for the formation of structural defects are studied along with their effect on the mechanical properties and fracture behaviour during tensile tests.

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.

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.

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.

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.

Minutes of the Meeting of the Editorial Board of the Journal Metalurgija.

6th International Symposium of Croatian Metallurgical Society "Materials and Metallurgy".

Revief and correction of foudation of Croatian Metallurgical Society.

The paper analyses the influence of blasting conditions on the properties of steel sheet RSt 37-2 having the gauge of 3 mm. Due to blasting, the surface roughness increases by an order and the surface strain hardening takes place to the depth of ca 0.06 mm, which results in compressive stress on the sheet surface. The above-mentioned changes, among others, increase the yield point and decrease the fatigue life in the tension-zero cycle. The increase of the yield point and the decrease of the fatigue life are more significant if the diameter of the blasting medium (within the tested interval from 0,56 to 0,9 mm) and the impact angle (30 to 75°) are greater at the air pressure of 0,4 to 0,5 MPa., U radu se analizira utjecaj pjeskarenja na svojstva čeličnog lima RSt 37-2 debljine 3 mm. Zbog pjeskarenja hrapavost površine se povećava za neki red veličine, a hladno otvrdnjavanje površine se proteže do 0,06 mm dubine, posljedica toga je tlačno naprezanje na površini lima. Gore spomenute promjene, između ostalog, povećavaju granicu razvlačenja a smanjuju vrijeme umora materijala pri cikličkom naprezanju. Povećanje granice razvlačenja smanjenje vremena umora materijala su značajniji ako su promjer medija pjeskarenja (unutar ispitivanog intervala od 0,56 do 0,9 mm) i udarni kut (30 do 75°) veći pri zračnom tlaku od 0,4 do 0,5 MPa.

The paper presents description of the production technology of microlayer composite materials for electric contacts of the system copper-zirconium-yttrium-molybdenum obtained by the method of electro-beam evaporation and layer condensation from the vapor phase and a study of their chemical composition, structure, electric conductivity, hardness, and main mechanical characteristics in the temperatur range from 290 to 1070 K.

A technique for determining strength characteristics of thin-sheet microlayer composite materials in transverse direction has been developed and tested. It has been found that the ultimate strength of the microlayer composite MDK-3 of the system Cu-Zr-Y-Mo in transverse direction, which characterizes the interlaminar strength of the material, is 350 to 400 MPa.

This paper deals with calculations of stress field, deformation field, strain rate field and temperature field in plastic deformation (rolling). The results of mathematical and physical simulations of rollings arc compared as well as the results of the software product in this paper. In metal forming we are mainly interested in the simulation of material flow. forces and stresses. Therefore an adequate material model is essential. For the analysis of forming problems we use a general mathematical description which expresses physical relations between stresses and deformations. Solving this equation is either possible by means of the method of finite differences or the finite element method (FEM). In technical applications we mainly use FEM. The base of software, which are used for the big plastic deformations such as MARC, FORGE, DEFORM, FORM, FORMFEM, is FEM.

The authors studied the regularities in the variation of characteristics of short-term, low-cycle, and long-term static strengths at short test duration in the temperature range from 290 to 3020 K, as well as the mechanism of plastic deformation and fracture modes for tungsten, molybdenum, niobium, and their alloys with hard-solution, dispersion, and mixed hardening produced by the vacuum arc melting (VAM) and powder metallurgy (PM) methods with the account taken of the material structural state and the manufacturing factors. Analysis and generalization of the obtained experimental data revealed that both specific and generalized correlation relationships exist among the mechanical characteristics of the refractory materials under the above loading conditions. The established correlation relationships make it possible to perform an accelerated evaluation and prediction of the characteristics of low-cycle and long-term static strengths and creep resistance of materials from the results of short-term tests.

The work presents a short theoretical review of the residual element influence on the plasticity and gives the comparison of the relations of the allamed residual element quantity steel, given in the world literature. Our research, carried out by torsion test methods in the temperature range 800 to 1250 °C, proved that residuals had a bad influence on the plasticity and yield stress casting structure, depending on ingot sue deformed structure.

The strength, deformability, and load-carrying capacity of niobium alloys of the Nb-W-Mo-Zr and Nb-Mo-Zr-C systems both in the initial state and with ceramic slip coatings based on molybdenum and hafnium silicides have been studied under conditions of short-term and long-term static tension in vacuum, inert medium, and in air in the temperature range from 290 to 2070 K. The investigation of the damage accumulated in the niobium alloy/silicide-ceramic coating composites under conditions of high-temperature tension revealed that cracks in the coating initiate already at early stages of plastic deformation (up to 0, 5 %). As a result of the investigation of creep and long-term strength of the composites, the values of the limits of 0, 5 % and 1, 0 % creep were obtained at temperatures of 1770 and 2070 K for the test time of 0, 1 ; 1, 0 and 10 hours. For instance, the creep stress of the niobium alloy of the Nb-W-Mo-Zr/silicide-ceramic coating composite inducing strains of 0, 5 % within the test time of 1 hour in argon is 25 MPa at 1770 K and 8 MPa at 2020 K. In air, the above values are higher accounting for 30 MPa at 1770 K and 10 MPa at 2020 K.

At the present time the topic of intense research is the refining of various type material structure, which has the low value of the basic deformation resistance during the bulk deformation processes by severe plastic deformation - SPD at the ambient temperature. The purpose of SPD is to obtain the result structure at the nm level (ultrafine structure) from the original mm level one. There are two ways of SPD realization: Equal-channel angular pressing - ECAP, and High-pressure torsion - HTP realized by high stress. In this study, the influence of severe plastic deformation (SPD) realized by ECAP procedure on structural, mechanical and plastic properties of ARMCO-Fe was inestigated. Mathematics simulation by FEM was applied, too.

Article deals with the mechanical, fatigue and brittle fracture properties of steel sheets of mark S 700 MC with minimum yield stress of 700 MPa. The chemical composition and technogical regime of rolling process were changed during development of studies steel. The experimental programme was realized at 7 randomly selected meltages (26 coiled sheets) of hot rolled steel sheets with the thickness of 8 and 10 mm. Tensile test showed that 14% of steel sheets had the lower yield stress level like was prescribed (Rm about 21 %) whereas the lower values were measured in longitudinal direction (Re about 9, 9%). Deformation properties in the rolling direction were higher about 38%. The scatter of mechanical properties is not affected by the thickness of steel sheets. The anisotropy of mechanical properties given by the ratio ReL / ReT is in the range from 0, 91 up to 1, 05, RmL / RmT in the range 0, 93 to 0, 97 and A5L / A5T from 1, 0 to 1, 38. Brittle fracture properties of studied steel is guaranteed at 0 °C by notch toughness KCU = 60 J• cm– 2. When U-notch was used, all studied steel sheets successfully passed notch toughness test al – 20 °C for guaranteed level 35 J• cm– 2.

The work deals with findings of possibility to increase the wear resistance of grooves of 250 wire mill finishing stand rolls by improving their cooling conditions, which provides increase in operating resistance of rolls 1.5-2 times

A two-layer ring of various thickness from and aluminium and a wheel in the shape of steel ring with steel or aluminium spokes were analysed by the FEM. In the first problem the plasticity of material was considered, and in the second, also- the possibility of spokes buckling. Conclusions about the efficiency of use of steel and aluminium in loaded elements of thinwalled structures are made. Dvoslojni obroč različne debeline iz jekla in kolo z jeklenim obročem in z jeklenimi ali aluminijastimi špicami sta bila analizirana po metodi FEM. V prvem primeru je bila upoštevana plastičnost materiala in v drugem tudi uklon špic. Oblikovani so zaključki o učinkovitosti uporabe jekla in aluminija v obremenjenih tankostenih strukturah. Nadaljuje se kot: Materiali in tehnologije

The deformation anomalies od higher orders at plastometric tests are studied on easily deformable lead alloys-model of different rheological complexity by original testing methods. It is ascertained that the development of deformation anomalies depends upon the degree of rheological complexity of materials. Simple strain anomalies are due to the inadequate conditions of contact friction, while those of the higher orders results mainly from microrelief of the simple butts. Recommendation for the obtention of homogeneity of deformation at plastometric tests are given. The tests show that the deformation of rheologically complex metals develops according to laws basically different of the contemporary notions of the mechanics of plastic deformation.

We present an approach to the development of a specialized-knowledge Internet portal for work with large quantities of information and computational resources in the field of strength of materials. The ontology-based portal provides an information basis for the design of alloys represented by the chosen fields of science, which may be difficult for formalizing, and it allows the use of web services for the realization of engineering tasks with the Internet and material-science knowledge that is accumulated in the databases.

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.