پديد آورنده :
يوسفيه، محمد
عنوان :
بهينه سازي و تاثير پارامترهاي پالسي در جوشكاري قوسي تنگستن-گاز بر رفتار خوردگي مقاطع جوش فولادهاي زنگ نزن سوپر دو فازي به كمك روش تاگوچي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
خوردگي و حفاظت مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان،دانشكده مواد
صفحه شمار :
يازده،119ص.: مصور،جدول،نمودار
يادداشت :
ص.ع.به فارسي و انگليسي
استاد راهنما :
مرتضي شمعانيان، احمد ساعتچي
استاد مشاور :
محمدعلي گلعذار
توصيفگر ها :
جريان پالسي , آناليز واريانس , عمليات حرارتي , آنيل مرحله اي
تاريخ نمايه سازي :
25/2/90
استاد داور :
حميدرضا سليمي، علي اشرفي
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Optimization of Pulsed GTAW Process Parameters on Corrosion Behavior of Super Duplex Stainless Steel Welds Using Taguchi Method Mohammad Yousefieh m yousefieh@ma iut ac ir July 12 2010 Department of Materials Engineering Isfahan University of Technology 84156 83111 Isfahan Iran Degree M Sc Language Farsi Dr Morteza Shamanian Assoc Prof Supervisor E mail shamanian@cc iut ac ir Dr Ahmad Saatchi Prof Supervisor E mail asaatchi@cc iut ac ir Dr Mohammad Ali Golozar Prof Advisor E mail golozar@cc iut ac ir Abstract In the present work a design of experiment DOE technique the Taguchi method has been used to optimize the pulsed current gas tungsten arc welding PCGTAW parameters for the corrosion protection of super duplex stainless steel UNS S32760 welds A L9 34 orthogonal array OA of Taguchi design which involves nine experiments for four parameters pulse current background current on time pulse frequency with three levels was used Corrosion resistance in 3 5 NaCl solution was evaluated by anodic polarization tests at room temperature Analysis of variance ANOVA is performed on the measured data and S N signal to noise ratios The higher the better response category was selected to obtain optimum conditions The optimum conditions providing the highest pitting potential were estimated The optimum conditions were found as the second level of pulse current 120 A second level of background current 60 A third level of on time 80 and third level of pulse frequency 5 Hz Under these conditions pitting potential was predicted as 1 08 VSCE that was very close to the observed value of 1 06 VSCE As a result of Taguchi analysis in this study the pulse current was the most influencing parameter on the corrosion resistance and the background current was the next most significant effect The percentage contributions of the pulse current the background current on time and pulse frequency to the corrosion resistance are 66 28 25 97 2 71 and 5 04 respectively Consequently the Taguchi method was found to be promising tool to obtain the optimum conditions for such studies Moreover the experimental results obtained confirm the adequacy and effectiveness of this approach Moreover in this research the influence of step annealing heat treatment on the microstructure and pitting corrosion resistance of super duplex stainless steel UNS S32760 welds have been investigated Pitting corrosion resistance in chloride solution was evaluated by potentiostatic measurement The results showed that step annealing treatments in the temperature range of 550 1000 C resulted in a precipitation of sigma phase and Cr2N along the ferrite austenite and ferrite ferrite boundaries At this temperature range the metastable pits mainly nucleated around the precipitates formed in the grain boundary and ferrite phase Above 1050 C the microstructure contains only austenite and ferrite phases At this condition the critical pitting temperature of samples successively arrived to the highest value obtained in this study Key Words Super duplex stainless steel Gas tungsten arc welding Pulse current Corrosion Taguchi method Analysis of variance Heat treatment Step annealing Precipitation
استاد راهنما :
مرتضي شمعانيان، احمد ساعتچي
استاد مشاور :
محمدعلي گلعذار
استاد داور :
حميدرضا سليمي، علي اشرفي
