پديد آورنده :
صرامي، ناهيد
عنوان :
ارزيابي فني و اقتصادي پوشش اكسيدي روي ورق هاي فولادي به روش آبي كردن حرارتي و روش شيميايي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
مهندسي مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مواد
صفحه شمار :
[نوزده]، 179ص.: مصور، جدول، نمودار
يادداشت :
ص.ع. به فارسي و انگليسي
استاد راهنما :
فخرالدين اشرفي زاده، فريماه مخاطب رفيعي
توصيفگر ها :
رفتار خوردگي , اكسيداسيون شيميايي , تحليل مالي , نقطه سربه سر
تاريخ نمايه سازي :
15/1/90
استاد داور :
محمود منير واقفي، ناصر ملاوردي
تاريخ ورود اطلاعات :
1396/10/10
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Metallurgical and Economical Evaluation of Oxide Coatings on Steel Sheets by Thermal Blueing and Chemical Process Nahid Sarrami Email address n sarami@ma iut ac ir Date of Submission August 30 2011 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors Fakhreddin Ashrafizadeh Professor ashrafif@cc iut ac ir Farimah Mokhatab Rafiei Assistant Professor farimah@cc iut ac ir Abstract Thin oxide coatings on metals can be stabilized by chemical thermal treatments in order to protect the metallic surface from atmosphere Amongst the processes for oxide conversion coatings on steel is the blueing process which is performed by several techniques In this research oxide coatings were produced on samples of carbon steel sheets by two thermal and chemical processes Thermal oxidation cycles were carried out on low carbon and high carbon steel sheet specimens and time temperature and cooling rate were studied as the process parameters To study the effect of temperature the specimens were oxidized at 300 350 400 450 500 and 600 C and were either air cooled or oil quenched Examination of coatings indicated that oxide layers produced at 450 C had a more uniform morphology Electrochemical impedance spectroscopy EIS was employed to compare the corrosion behaviour of the specimens and the oxide film was optimized in terms of surface colour and EIS characteristics The structure and surface topography were examined by optical and scanning electron microscopy and mechanical properties of the layers were evaluated by nano indentation testing Experimental results indicate that corrosion resistance of the coated sheets depends on the oxidation process parameters which may be optimized according to the application Surface colour of the oxide is determined by interference effect being a function of film thickness But the corrosion behaviour was independent of the surface colour In the second part of this study the thermal blueing and chemical processes were compared on an economical basis The economical evaluation of the two processes was carried out to present the cash flows of alternative methods in a 10 year period from 2011 to 2021 For each cash flow three net present values NPV were calculated using three different interest rates Each interest rate is affected by the inflation rate and minimum attractive rate return MARR where MARR 10 15 20 and the inflation rate is based on the forecasted values According to the economical study the cost of product steel strap coated by thermal method is approximately 15 less than the cost of product obtained by chemical Oxidation treatment Keywords Oxide coatings Blueing process Corrosion resistance Chemical oxidation Economical evaluation
استاد راهنما :
فخرالدين اشرفي زاده، فريماه مخاطب رفيعي
استاد داور :
محمود منير واقفي، ناصر ملاوردي
