4276

4047

كارشناسي ارشد

شناسايي وانتخاب مواد

اصفهان: دانشگاه صنعتي اصفهان ، دانشكده مواد

1387

نه، 94، [II]ص.: مصور، جدول، نمودار

ص. ع. به: فارسي وانگليسي

عباس نجفي زاده

23/07/1387

احمد جنابعلي جهرمي، محمدرضا طرقي نژاد

مهندسي مواد

ID4047

به فارسي وانگليسي: قابل رويت درنسخه ديجيتال

Abstract In this study the kind of thermo mechanical processing martensite processing wasinvestigated At first for optimizing the Dual phase heat treatment the low carbon Nb steelwith appropriate chemical composition were homogenized at 1100 C for 3 hours and thenforged at 1000 C to 50 reduction The detection of intercritical temperatures was performedby the dilatometery test The specimens of dual phase steels with variety percent ofmartensite phase and grain size were cold rolled to 20 80 reduction and then annealing at400 600 C for 30 miniutes was carried out Microstructural observations showed that grainsize and amount of martensite phase varied with different holding time and temperature indual phase region The specimen that held in 880 C for 5 minutes had lowest grain size andpercent of martensite By increasing the holding temperatures strength increased but byincreasing holding time strength decreased Cold rolling to 80 and annealing of thespecimen that was produced at 920 C for 300 seconds increased tensile strength to 810 MPawith adequate uniform elongation to 12 2

عباس نجفي زاده

احمد جنابعلي جهرمي، محمدرضا طرقي نژاد