8640

8021

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1392

سيزده،84ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

مسعود پنجه پور، محمود مرآتيان

21/12/92

علي سعيدي،، مهدي احمديان

مهندسي مواد

ID8021

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

Synthesis of cementite from hematite graphite mixture by mechanical thermal and fractional melting processes Soleymani Amir Peyman ap soleymani@ma iut ac ir January 22 2014 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Dr Masoud Panjepour Assoc Prof Supervisor Email panjepour@cc iut ac ir Dr Mahmoud Meratian Assoc Prof Supervisor Email meratian@cc iut ac ir Abstract In the recent years pure cementite Fe3C is considered as a material for the production of high temperature usage pieces and an auxiliary material in electric arc furnaces EAF For this purpose simultaneous thermal mechanical activation STMA was performed on hematite graphite mixtures with stoichiometric ratio of 1 1 1 25 1 and 1 5 1 stoichiometric amount of consumed carbon in hematite to cementite reaction for 6 hours at 800 850 and 900 C and BPR of 40 1 The microstructure of the sample which was milled at 800 C and carbon to hematite ratio of 1 1 was studied through light microscope Scanning electron microscope SEM and energy dispersive spectroscopy EDS The results showed pearlite proeutectoid cementite and activated free carbon content in the microstructure Image analysis of the sample indicated more than 2 1 wt carbon content which was approved by eutectic endothermic peak in thermal analysis DSC To dissolve the free carbon content in the microstructure of the sample fractional melting FM process was performed on the sample at 1180 C for 25 min in inert atmosphere Microstructure of this sample showed more than 75 wt proeutectic cementite and 5 7 wt carbon content Further studies were done on the FM samples which had higher stoichiometric ratio 1 25 1 and 1 5 1 and higher milling temperature 850 C and 900 C Microstructure of these samples was surveyed through light microscope and color etching solutions SEM and EDS The image analysis results indicated that increasing stoichiometric ratio and milling temperature increased the cementite in the structure So that increasing the source of carbon led to cementite and vermicular graphite microstructure in the sample which was milled at 800 C with 1 5 1 stoichiometric ratio While fragmentation and distribution of graphite particles in the sample which was milled at 900 C with 1 25 1 stoichiometric ratio was the mechanism of cementite graphite microstructure According to the results coupling of STMA FM process can be brought up as a new method for pure cementite production from hematite Keywords Iron carbide Hematite Graphite Simultaneous Mechanical thermal activation Fractional Melting Hot ball milling Carbothermic reduction

مسعود پنجه پور، محمود مرآتيان

علي سعيدي،، مهدي احمديان