رويه كاري فولادهاي رنگ نزن مارتنزيتي با استلايت 6 و ارزيابي ساختار، رفتار سايشي و خوردگي

چكيده انگليسي :

IUT 77142 Degree Master of science in Materials Engineering Title Hardfacing of stellite 6 on martensitic stainless steel and evaluation of microstructure wear and corrosion behavior Author Maral Ahmadpour Samani Supervisor M Shamanian A Saatchi Department Materials Engineering Date April 18 2009 Language Persian Abstract Hardfacing is also used to increase wear and corrosion resistance and reduce friction coefficient The valve face of the engine valves is subjected to high frequency impact high temperatures and erosion resulting from high temperature exhaust gases flowing at velocities as high At present the main preventive measure for the above problem is to apply a layer having a good thermal resistance corrosion resistance and wear resistance on the valve face Significant efforts have been use of cobalt based alloys containing carbides that show an enhanced wear and corrosion resistanceIn this research microstructure Vickers hardness profile corrosion and wear behavior and phase formation before and after wear test of consecutive layers of a cobalt based alloy Stellite 6 were deposited onto 410 stainless steel One two and three consecutive layers and one layer stellite 6 with 309austenitic stainless steel and inconel 617 interlayer were investigated Gas Tungsten Arc Welding GTAW cladding were carried out for depositing The specimens were investigated by an optical metallogaphy X ray diffractometer energy dispersion spectroscopy EDS scanning electron microscope SEM and hardness test The microstructure of the clad layer consists of eutectic structure carbides dispersed in the FCC matrix Co with dendritic structure The carbides are M7C3 and M23C6 M refers to metal which are mainly compounds of chromium Interface and dendrites have epitaxial growths There was a gradual increase in the hardness from the substrate towards clad surface due to the decrease in the size of dendrites and the hardness near the substrate is low because of the dilution of the clad layer with Fe from the substrate 309austenitic stainless steel Interlayer results dilution of Fe were decreased and hardness were increased Inconel 617 interlayer cause decrease in hardness from 1 layer to 3 layer specimen the wear resistance of the clad layer were increased 309 austenitic stainless steel Interlayer specimens have the highest wear resistance Wear rate and weight loss of Inconel 617 interlayer specimens are highest level After wear test hardness and HCP Cobalt phase were increased The IULFWLRQ FRHIILFLHQW RI VWHOOLWH ZDV DQG ZLWK LQFRQHO LQWHUOD HU ZDV KLJKHU The corrosion rate of 3 layer specimens were low and the passive region was longer than other specimens the passive current for stellite coatings with interlayers were lower than 1 and 2 layer but the passive regions were smaller The corrosion rate of speciments with interlayer were lower than other speciments Keywords stellite 6 martensitic stainless steel inconel 617 interlayer microstructure corrosion and wear behavior Gas Tungsten Arc Welding pdfMachine is a pdf writer that produces quality PDF files with ease Get yours now Thank you very much I can use Acrobat Distiller or the Acrobat PDFWriter but I consider your product a lot easier to use and much preferable to Adobe s A Sarras USA

احمد پورساماني، مارال

رويه كاري فولادهاي رنگ نزن مارتنزيتي با استلايت 6 و ارزيابي ساختار، رفتار سايشي و خوردگي

اينكونل 617 , لايه مياني , جوشكاري قوسي تنگستن-گاز , رقت