پديد آورنده :
نياكان، حميد
عنوان :
بررسي خواص ميلگردهاي آجدار از جنس فولاد دوفازي
مقطع تحصيلي :
كارشناسي ارشد
گرايش تحصيلي :
شناسايي و انتخاب مواد
محل تحصيل :
اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد
صفحه شمار :
[هشت]، 90، [II]ص.: مصور، جدول، شكل، نمودار
استاد راهنما :
عباس نجفي زاده، مرتضي شمعانيان
توصيفگر ها :
استحكام مارتنزيت , ريختگري فولاد , آزمايش ديلاتومتري، عمليات حرارتي، نورد گرم،كشش , متالوگرافي
استاد داور :
جنابعلي جهرمي، علي شفيعي
تاريخ ورود اطلاعات :
1396/02/31
چكيده فارسي :
به فارسي و انگليسي: قابل رويت در نسخه ديجيتالي
چكيده انگليسي :
Abstract Dual phase steels DP consisting of structures of ductile ferrite and hard martensiteislands show superior mechanical properties to commercially available high strength lowalloy steels In this study the effects of hot rolling parameters such as reduction percentage rolling and coiling temperature on the microstructure and mechanical properties of dualphase steel with and without niobium were investigated It is well known that one of thekey factors to achieve a dual phase structure is the chemical composition so anappropriate chemical composition was chosen in order to produce as rolled DP steel Melting process was carried out with an induction furnace Then the product wereforged and homogenized before undergone rolling process Three different thicknessreduction i e 15 30 and 50 two different rolling temperatures 950 and 850 C andtwo coiling temperatures 550 and 400 C were used For identify the mechanicalproperties and microstructural evolution the tension tests microhardness measurement andoptical microscopic observation were applied The results showed that all specimens displayed a continuous yield point Rolling in dualphase region and coiling at low temperature demonstrated elongated grains in the rollingdirection Those elongated grains were not observed as coiling temperature increased Inrolling of the DP steel with a constant rolling and coiling temperature increasing thicknessreduction increased yield and tensile strength and decreased the total elongation It wasalso observed that the coiling temperature have an important effect on proportion ofmartensite phase as this temperature decreased the proportion of martensite was increased Comparison of specimens with and without Nb showed that specimens containing Nb hadhigher yield and tensile strength martensite proportion ferrite microhardness and lowertotal elongation and ferrite grain size It was also observed that in specimens with Nb bainite and pearlite phases couldn t form
استاد راهنما :
عباس نجفي زاده، مرتضي شمعانيان
استاد داور :
جنابعلي جهرمي، علي شفيعي
