DUCTILE IRON MICROSTRUCTURE DESIGN USING HEAT TREATMENT PROCESSES
Mechanical properties of the ductile iron strongly depend on its microstructure. Different microstructural constituents result in different values of mechanical and ductile properties of ductile iron castings. One of the possibilities to design (define) microstructure of ductile iron castings is an application of different heat treatment processes....
By Hasan Avdušinović, Salaheldin Abdelmagid Mohamed Badreldin, Mohammed Abdelgadir Abdalla Mohammed, Faik Uzunović
HEAT TREATMENT OF LOW ALLOYED STEELS 17CrNiMo6 AND 20CrMo5 – CARBURIZATION
This paper is concerned with carburization heat treatment. Standard carburization generally entails several steps: carburization of the surface layer by carbon diffusion at high temperatures, subsequent hardening and stress relief. This combination of hard surface and resistance to breakage upon impact is useful in parts such as a cam or ring gear,...
By Belma Fakić, Mohamed Fadlalla Mohamed Ahmed, Babekir Ahmed Osman Mohammed, Faik Uzunović
EFFECT OF DEFORMATION AND HEAT TREATMENT ON MICROSTRUCTURE OF WARM ROLLED STEEL IN ALPHA-GAMMA AREA
In this paper the effect of different heat treatment (recrystallization, spheroidizing and normalizing) processes on microstructure of the steel DC04 intended for deep drawing is presented. The steel is cladded with CuZn10 layers by explosive welding. Since the melting temperature of alloy CuZn10 is significantly lower (melting range 1025-1045 oC) ...
By Omer Beganović, Belma Fakić, Ali Mohammed Ali Mohammedzain, Babekir Ahmed Osman Mohammed, Faik Uzunović
OPTIMISATION OF CHAMBER FURNACE TECHNOLOGICAL PARAMETERS FOR HIGH CHROMIUM STEEL ROLLS HEAT TREATMENT
In this work, industrial control technical measurements of the heat treatment of high chromium steel (HCS) rolls is presented.Measurements were carried out on the gas fired car bottom chamber furnace Bosio PP-KP 70/1150 in the company Valji d.o.o., Štore, Slovenia. Temperature measurements of the individual heating zones of the furnace, roll...
By Blaž Karpe, Simon Rečnik, Aleš Nagode, Borut Kosec, Sergej Novak, Stjepan Kožuh
THE MICROSTRUCTURE OF THE SCALE FORMED DURING THE HIGH TEMPERATURE OXIDATION OF A FeCrAl ALLOYS
FeCrAl alloys have good oxidation resistance at elevated temperature owing to the formation of a continuous Al2O3 surface film, which acts as an oxygen diffusion barrier. The aim of the present study was to investigate the early stages of protective oxide layer formation and its growth on specially prepared commercial FeCrAl alloys, Kanthal AF (K-A...
By Stojana Veskovič, Milan Bizjak, Blaž Karpe, Aleš Nagode, Samo Smolej, Janez Kovač, Gorazd Kosec
HIGH-STRENGTH CONCRETE (HSC) MATERIAL FOR HIGH-RISE BUILDINGS
Successful examples of high–rise buildings in the world are obvious evidences that the use of high–strength concrete is nowadays reality in construction worldwide. Whether focus on high–rise buildings up to 15– 24 storeys, or the super tall high–rise buildings that are few hundred of storeys high, high–strength c...
By Ilda Kovačević, Sanin Džidić
PROGNOSIS OF REACTIVITY AND STRENGTH OF COKE BASED ON MODIFIED BASICITY INDEX MODEL
Metallurgical coke, as a fuel and a reducing agent, also allows for the gas to go through a charge in the blast furnace. The coke must have a strength, porosity, reactivity and a uniform granulation, because reaction of CO2 at high temperatures in the furnace. There are various mathematical models for the optimization of coal blend, which allow the...
By Sulejman Muhamedagić, Mirsada Oruč, Admir Muminović, Amina Kurtović
CAVITATION OF REFRACTORY SAMPLES BASED ON TALC AND ZEOLITE FROM ZLATOKOP, SERBIA
Samples based on talc with 15 % of zeolite from Zlatokop, Serbia, sintered at 1200 ºC were prepared and tested in condition of cavitation erosion. The ultrasonic vibratory cavitation set up with stationary specimen was used. Mass loss was measured and degradation level of the samples using image analysis and Young modulus of elasticity was mon...
By Jelena Majstorović, Sanja Martinović, Milica Vlahović, Marina Dojčinović, Marko Pavlović, Tatjana Volkov Husović
THE EFFECTS OF THE DISTRIBUTION COEFFICIENT ON THE PROPERTIES OF THE REFRACTORY CASTABLES FROM THE CHAMOTTE WASTE AND CLAY “RAPAJLO”
The paper examined the conventional castables composed of a mixture of high aluminate cement with 70% Al2O3, chamotte waste with 42% Al2O3 and brick clay ,,Rapajlo“. The influence of particle size distribution on density, porosity, water absorption, modulus of rapture and cold crashing strength was investigated. Particle size distribution was...
By Marina Jovanović, Adnan Mujkanović, Nadira Bušatlić
THE EFFECTS OF NANOSILICA ON THE PHYSICAL-MECHANICAL PROPERTIES OF CONCRETE
The physical-mechanical properties of concrete with nanosilica were experimentally studied. Nanosilica in powder form was used as a partial replacement of cement at dosage of 3 and 6 wt.%. The experimental results show that the compressive strengths of concretes with nanosilica particles were all higher than those of reference concretes at ages 1, ...
By Adnan Mujkanović, Marina Jovanović, Amel Zahirović