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Article Variations in Chemical Composition of Some Steels During Continuous Casting(Springer, 2012) Keskinkilic, E.In this study, chemical composition variations of some steels during continuous casting were investigated in Eregli Iron and Steel Works Co. (ERDEMIR), Turkey. Final chemical analysis of a heat is determined in the continuous casting stage. Three steel specimens are regularly taken from the mould at certain meters of slab strand for each heat. The aim of this work was to evaluate the extent of changes in chemical analysis along the slab strand. Consequently, the leading aim of this study was to determine whether the number of specimens taken for each heat could be decreased without compromising quality control of the continuous casting. This was accomplished for some low-carbon, ultra-low carbon, and structural steels, which constitute the majority part of the ERDEMIR product range. The results revealed that the number of specimens could only be decreased for a limited number of steels and under certain circumstances.Article Citation - WoS: 17Citation - Scopus: 17Calcination Characteristics of Laterite Ores From the Central Region of Anatolia(Southern African inst Mining Metallurgy, 2012) Keskinkilic, E.; Pournaderi, S.; Geveci, A.; Topkaya, Y. A.; Metallurgical and Materials EngineeringDrying, calcination, prereduction, and smelting are the main steps in conventional crude ferronickel production. Industrially, these steps are conducted using the rotary kiln-electric arc furnace (RKEF) process. In this paper, calcination characteristics of Sivrihisar laterite ores from the Central Anatolia region are investigated. The extent of elimination of chemically bound water and other volatiles was studied by experiments conducted at various temperatures in the 250-800 degrees C range. Phase changes were examined using X-ray diffractometry. For the particle size used in the study, 300 degrees C was determined to be almost sufficient for complete transformation of goethite to haematite, and 700 degrees C was required for effective elimination of all volatiles in the ore.Article Citation - WoS: 9Citation - Scopus: 11Reducibility of Nickeliferous Limonitic Laterite Ore From Central Anatolia(Taylor & Francis Ltd, 2014) Pournaderi, S.; Keskinkilic, E.; Geveci, A.; Topkaya, Y. A.Limonitic nickel laterite from Sivrihisar reserve in Turkey was reduced at 700-1100 degrees C by the addition of 5.74, 8.61 and 11.48 wt-% coal under an argon atmosphere. The run-of-mine ore and the reduced samples were studied using X-ray diffraction. The metallisation of Fe was found to be limited up to 900 degrees C, but increased rapidly at higher temperatures. The metallisation of Ni and Co increased when the temperature was increased from 700 to 800 degrees C, almost levelled off up to 900 degrees C and then increased up to 1100 degrees C. The results also showed that increased coal additions did not affect Fe metallisation up to 900 degrees C. At 1000 degrees C the metallisation of Fe became slightly better, but its effect was more pronounced at 1100 degrees C. The increased coal addition affected the nickel reduction equally at all temperatures, while it had no effect on the metallisation of Co.Article Citation - WoS: 5Citation - Scopus: 7Sulfide-Type Inclusion Morphologies of a Ca-Treated Hot-Rolled Wheel Steel(South African inst Mining Metallurgy, 2011) Keskinkilic, E.; Metallurgical and Materials EngineeringIn this study, sulfide-type inclusion morphologies of a Ca-treated hot-rolled wheel steel, Grade-X, were investigated. The specimens taken from the hot-rolled products of Grade-X heats were studied. The size and distribution of elongated sulfide inclusions were examined for the heats of different S levels. Elongated sulfide inclusions were either not observed or rarely encountered when ladle analysis S content was below 50 ppm. The size and relative abundance of sulfide inclusions were reported to increase markedly when the S composition was greater than or equal to 70 ppm and the Ca/S ratio was less than 0.50. The effect of Ti addition (0.010-0.020% Ti) on sulfide-type inclusion morphologies was then investigated for heats having a sulfur content higher than 50 ppm. Addition of Ti was found to have a partial effect on decreasing the size of sulfide-type inclusions under real steelmaking conditions.
