8124

7522

كارشناسي ارشد

جوشكاري

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1391

سيزده،63ص.: مصور،جدول،نمودار

ص.ع.به فارسي و انگليسي

محمدعلي گلعذار، فخرالدين اشرفي زاده

مهدي ميرجاني، فتح اله كريم زاده

18/8/92

مرتضس شمعانيان، كيوان رييسي

مهندسي مواد

ID7522

به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي

The influence of repeated welding on the mechanical properties microstructure and corrosion resistance of welded sections of micro alloy high strength P N steel Meysam Gholami Meysam gholami@ma iut ac ir March Department of Materials Engineering Isfahan University of Technology Isfahan Iran Degree M Sc Language Farsi Supervisors Prof Mohammad Ali Golozar E mail golozar@cc iut ac ir Prof Fakhreddin Ashrafizadeh E mail ashrafif@cc iut ac ir ABSTRACT P N Welded steel has several applications in the naval environments The weld regions of this steel frequently need repeated repairs In this research the influence of repair welding on microstructure mechanical and corrosion properties of P N steel was studied For this purpose four samples without repair one repair twice repair and three times repair were welded Temper bead welding repair procedure was performed The quality of all welded samples was assessed using radiography technique Microstructures of the base metal heat affected zone HAZ and weld metal were examined by optical microscopy and scanning electron microscopy To evaluate mechanical properties tension impact bending and Vickers hardness tests were performed Evaluation of corrosion resistance was performed using Tafel polarization test Aqueous wt sodium chloride solution was selected as the corrosive environment The results indicated that corrosion current of the heat affected zone decreased with increasing the number of repairs Corrosion rate of the base metal was higher than that of weld and HAZ for different number of weld repairs The hardness values of the heat affected zone near the base metal showed significant increase in one time repair compared with the no repair specimen in the two and three times repair the Vickers hardness number decreased by increasing the number of weld repairs The hardness of the heat affected zone near the weld metal increased with increasing the number of repairs Tension impact and bending tests passed the acceptance criteria of ASME IX The impact energy of the heat affected zone showed an increased after one repair and then a decrease after the subsequent repairs Ultimate tensile strength of on repair specimens was more than the others N Steel Temper bead Corrosion Heat affected zone Keyword weld repair P PDF created with pdfFactory trial version www pdffactory com

محمدعلي گلعذار، فخرالدين اشرفي زاده

مهدي ميرجاني، فتح اله كريم زاده

مرتضس شمعانيان، كيوان رييسي