پديد آورنده :
شعبانيان، صدف
عنوان :
ارزيابي آسيب در گرمكن آبي و امكان استفاده از پوشش هاي محافظ براي كنترل خوردگي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
شناسايي و انتخاب و روش ساخت مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مهندسي مواد
صفحه شمار :
چهارده، 98ص.: مصور
استاد راهنما :
فخرالدين اشرفي زاده
توصيفگر ها :
فولاد ساده ي كربني , خوردگي زير رسوبي , خوردگي خط آب , پوشش مس , كروماته , گالوانيزه
استاد داور :
مهران نحوي، عبدالمجيد اسلامي
تاريخ ورود اطلاعات :
1395/05/30
چكيده انگليسي :
99AbstractIn this research corrosion failure of coil tubes fire tubes and inner surface of the shellfrom a large water bath heater have been described Water bath heaters are designed to heatthe gas prior to the pressure reduction Such heating prevents damage of equipment causedby the ice particles within the water vapor from the gas that can occur because of asubstantial temperature drop during pressure reduction In order to study the main cause ofthe failure non destructive and destructive tests including evaluation of mechanicalproperties x ray diffraction scanning electron microscopy energy dispersive spectroscopymicroanalysis of corrosion products on specimens prepared from coil tubes and chemicalanalysis of water used in the heater were carried out Based on the experiment outcomes the chemical composition of steel was approved according to the standard but industrialdistilled water had a high amount of total dissolved solids The results indicated thatinsufficient control of water level in the tank resulted in oxygen concentration corrosionand water line corrosion After evaporation of water droplets on the roof a residueremained on the surface leading to under deposit corrosion and through that a blister likedamage took place on the shell roof After detachment corrosion products and scales felldown and remained on the upper surface of the components Since water inside the heaterwas stagnant accumulation of deposits created oxygen concentration cells and corrosionunder deposits have spread out Heat transfer medium in bath heaters is including of amixture of industrial distilled water and 20 Vol ethylene glycol In order to investigatethe corrosivity of water the effect of ethylene glycol concentration on the corrosion ofcarbon steel was studied Results revealed that water containing 10 40 ethylene glycolhad the lowest corrosion rate Based on the results of failure analysis a study wasconducted on the possible solutions some experiments were carried out to evaluate severalpotential protective coatings including copper chromate and hot dip zinc galvanizing Copper coatings produced by thermal spray method and electroplated in copper sulfatesolution for sealing Then in order to increase the wettability angle and hydrophobicity ofthe surface the specimen was electroplated in zinc chloride solution and immersed in asolution of stearic acid and ethanol Electrochemical tests revealed that the proposedcoatings improved the corrosion resistance in an increasing order in galvanized chromateand hydrophobic copper respectively Keywords water bath heater carbon steel under deposit corrosion water line corrosion copper coating chromate galvanized
استاد راهنما :
فخرالدين اشرفي زاده
استاد داور :
مهران نحوي، عبدالمجيد اسلامي
