7542

7014

كارشناسي ارشد

خوردگي و حفاظت از مواد

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

نه،97ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

احمد ساعتچي، محمود منير واقفي

8/12/91

علي شفيعي، محمد ژياني

مهندسي مواد

ID7014

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

98 The effect of Cr3C2 NiCr coating using HVOF technique in decreasing metal dusting of HP alloy Amir mahdi Shabani a shabani@ma iut ac ir Date of Submission Jun 21 2013 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors M Monirvaghefi Associate Professor vagh mah@cc iut ac ir A Saatchi Professor asaatchi@cc iut ac ir Abstract One of the most important types of destruction is corrosion in high temperatures which consists of reactions of metal with gas or molten metal Metal dusting is a reaction between metal and gas at temperatures up to 600OC or higher that occurs in reformer tubes during exposing to a carbon contained gas and in direct iron ore reduction industry The aim of this study is to decrease metal destruction or to prevent reaction between metal and environment by applying suitable coatings For this the selective substrate was HP steel alloy which is used in reformer tubes The cut sections from the mentioned alloy were coated by Cr3C2 NiCr coating using HVOF technique and then exposed to methane gas at 680 and 800 OC The samples before and after deposition were evaluated using SEM XRD and EDS techniques The results showed significant decreases of graphite deposited through reducing diffusion of carbon in sample surface in both temperatures and also generation of stable chromium oxides especially in 800OC Also it was found that the influence of coating in 680 C was more than that of 800 c The reduction of diffusion rate of carbon as a result of deposition in 680 c and 800 c was 30 and 10 respectively Moreover the substrate surface was protected by the coating which generates a protective and adhesive barrier Keywords Metal dusting Cr3C2 NiCr coating HP HVOF

احمد ساعتچي، محمود منير واقفي

علي شفيعي، محمد ژياني