CALIBRATION OF THE LIGHT MICROSCOPE
Metallic materials thanks to the excellent combination of data on material properties are obtained by standardized and agreed testing of samples made from semi-finished or finished products. Metallic materials can be tested by different testing techniques. One of them is metallographic testing, for which a light microscope is used as a basic device...
By Adisa Burić, Belma Fakić, Edib Horoz, Mirsada Oruč
TESTING SURFACE ROUGHNESS AFTER DIFFERENT TECHNOLOGICAL PHASES OF PROCESSING NIMONIC 80A
Surface roughness is the totality of microgeometric irregularities on the surface of an object and it is caused by various factors, from which the most important are machining and processing techniques. This characteristic of the material is very important, especially in the case of high-quality materials designed for the demanding conditions of ex...
By Raza Sunulahpašić, Mirsada Oruč, Edina Karić
STUDY OF THERMAL PROPERTIES AND MICROSTRUCTURE OF THE Sn-Ag ALLOYS
Thermal properties and microstructure of the Sn-10% Ag and Sn-20% Ag alloys were experimentally investigated in this study. Melting behavior of the alloys were studied using differential scanning calorimetry (DSC). Microstructure of the alloys was analyzed by optical microscopy. The xenon-flash method was used for the measurements of thermal diffus...
By Dragan Manasijević, Ljubiša Balanović, Ivana Marković, Duško Minić, Aleksadar Đorđević
SIGMA PHASE PRECIPITATION IN AUSTENITIC STAINLESS STEELS
The precipitation of sigma (σ) phase in austenitic stainless steels is a significant subject of many investigations. Exposure of these steels to elevated temperatures (from 600 °C to 900 °C) results in precipitation of σ phase (transformation product from delta (δ) ferrite) which is one of the main reasons for the deterior...
By Amna Hodžić, Almaida Gigovic-Gekic, Raza Sunulahpašić
SPECIFIC ASPECTS IN POSITIONING OF THE RE-HEATING FURNACES AT A LAYOUT OF MANY DIFFERENT ROLLING MILS
Some specific aspects in positioning of the re-heating furnaces at a layout of different rolling mills, for a period of about last hundred years in rolling mills practice are presented in this paper. Practical solutions in the above mentioned (a.m.) field are presented for the different rolling mills. Some of the a.m. aspects are explained, confirm...
By Omer Beganović, Faik Uzunović
THE INFLUENCE OF TEST TEMPERATURE ON THE TOTAL ENERGY OF IMPACT
The paper describes the behavior of welded joints of NN-70 steel in the presence of a cracking error when bending with impact force. The experiment was performed with three groups of test tubes, depending on the cut-off point of the test tube notch with the tip of the crack in BM, in WM and in HAZ. The test method used was conducted on the instrume...
By Nermin Bišćević
THE INFLUENCE OF CARBON IN SYNTER-MIXTURE ON THE MECHANICAL RESISTANCE OF THE PRODUCED SINTER
The ore consolidation process is a thermal process and it happens at the temperatures of the ore melting beginning, allowing the ore grains, additives and fluxes to be connected into a solid piece of sinter. The amount of carbon in the sinter mixture and the FeO content of the produced sinter affect the mechanical resistance of the sinter. Indicato...
By Sulejman Muhamedagić, Mirsada Oruč, Amna Karić
THE INFLUENCE OF THE RHEOLOGICAL PARAMETERS OF THE COAL MIXTURE ON THE STRENGTH OF METALLURGIC COKE
Metallurgical coke as a fuel, reducing agent and permeable material in high-pressure processes must have pronounced strength and granulation properties due to expected changes in high temperature conditions. The best quality of metallurgical coke is achieved when coal mixtures satisfy a certain range of rheological parameters. The characterization ...
By Sulejman Muhamedagić, Amina Kurtović, Azra Halilović
HEAT RESISTANCE OF HK30Nb STAINLESS STEEL PIPE CASTING
The HK30Nb steel pipe casting was obtained by centrifugal casting. This steel is austenitic stainless steel grade AISI HK 30 and is standardized according to ASME SA-351 in as cast condition. HK 30 Nb steels not standardized i.e. it is HK 30 steel modified with niobium. In addition to the required mechanical properties, this steel is also tested fo...
By Mirsada Oruč, Alen Delić, Almaida Gigovic-Gekic, Raza Sunulahpašić
INFLUENCE OF MICROALLOYING WITH BORON, ZIRCONIUM AND TELLURIUM ON THE MODIFICATION OF NONMETALLIC INCLUSIONS OF AUSTENITIC STAINLESS STEEL WITH SULPHUR ADDITION
The basic characteristics of the chemical composition of steel with improved machinability (X8CrNiS18-9) are the increased content of sulphur (0.15-0.45%), phosphorus (0.07-0.11%) and manganese (0.5-1.5%). Sulphur by creating sulphide inclusions reduces friction and cutting resistance, and increases the brittleness of the chip.Considering its harmf...
By Derviš Mujagić, Aida Imamović, Mustafa Hadžalić