14628

13179

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان : دانشگاه صنعتي اصفهان

1398

ده، 92 ص. : مصور، جدول، نمودار

فتح اله كريم زاده، محمد حسن عباسي

محمد حسين عنايتي، محمود منير واقفي

1398/02/25

كتابنامه

مهندسي مواد

مهندسي مواد

1398/02/25

2533751

93Development and characterization of Inconel 718 composite claddings on 304L stainless steel Zahra Aghaei zahra aghaei@ma iut ac ir Date of Submission April 28 2019 Department of Materials Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Supervisor Fathallah Karimzadeh Professor karimzadeh f@cc iut ac ir Supervisor Mohammad Hassan Abbasi Professor abbasi32@cc iut ac ir Department Graduate Program Coordinator Dr Masoud AtapourAbstractAustenitic stainless steels have found their wide applications in different industries due to the highcorrosion resistance good formability and appropriate weldability However the wear resistance ofstainless steels reduces at high temperatures which can limit some of their possible applications Surface engineering methods can be used as a solution to improve the surface mechanical propertiesof stainless steels In the present study Inconel 718 claddings were prepared on the surface of 304Lstainless steel by using gas tungsten arc welding GTAW method The microstructure and hightemperature wear properties of the claddings were carefully investigated The effect of dilution andthe addition of Al2O3 particles were also studied The microstructure of the claddings wasinvestigated by scanning electron microscopy SEM while the hardness and yield strength weremeasured by nanoindentation method The wear behavior of substrate and claddings was investigatedat room and high temperatures by using high chromium tool steel and Al2O3 balls respectively Itwas found that the microstructure of single layer IN718 cladding consists of a phase matrix andNb rich laves phase The chemical composition of matrix and also the content of laves phases aredifferent at different parts of the claddings The microstructure of double layer IN718 cladding isfound to be similar to the single layer cladding but with high amount of TiC carbides close to theinterface of steel substrate This was related to the thermal cycle of the second pass of the claddingprocess Homogenous distribution of Al2O3 particles were found in the microstructure of thecomposite cladding The addition of Al2O3 resulted in the enhancement of hardness and yield strengthof the composite cladding compared to the single layer and double layer IN718 claddings Thecomposite cladding shows inferior wear resistance compared to the double pass IN718 despite of itshigher hardness The abrasive wear mechanism was recognized as the dominant wear mechanism forall of the claddings at 500 C It was also observed that the wear debris form a glazed layer on thetop of wear track during high temperature wear test resulted in the reduction of wear rate However the Al2O3 particles deteriorate this glazed layer led to the high wear rate of the composite cladding Annealing of the double layer IN718 cladding at 1080 C followed by two stage aging at 720 and620 C led the dissolution of laves phases and precipitation of fine intermetallics and or carbidephases resulted in considerable increase in the hardness of cladding as well as reduction of wearrate Keywords Cladding Austenitic stainless steels IN718 High temperature wear test Nanoindentation laves phase Nb and Ti rich intermetallic compounds

فتح اله كريم زاده، محمد حسن عباسي

محمد حسين عنايتي، محمود منير واقفي