4606

4334

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان : دانشگاه صنعتي اصفهان ، دانشكده مواد

1387

ده ، 98 ، [II] ص: مصور ، نمودار ، جدول

ص.ع. به: فارسي وانگليسي

عباس نجفي زاده ، احمد كرمانپور

88/5/11

فخرالدين اشرفي زاده ، محمد رضا طرقي نژاد

1396/09/13

كتابنامه

مهندسي مواد

ID4334

به فارسي وانگليسي: قابل رويت در نسخه ديجيتال

Abstract In this study production of nanostructure 301 austenitic stainless steel by cold rolling annealing thermomechanical process is investigated In used steel austenite transforms tostrain induced martensite by cold rolling Reversion of strain induced martensite toaustenite in subsequent annealing leds to formation of ultra fine grain austenitic structure For this purpose annealing parameters of cold rolled 301 stainless steel was studied toproduce a nanostructured austenite Phase transformations was studied by means of XRD feritscope and dilatometer also microstructures was observed by means of optic andscanning electron microscopes Results showed that by 60 cold roll after quenching at 10 C all of the austenite wastransformed to strain induced martensite Annealing of the 90 cold rolled 301 stainlesssteel at temperatures above 700 C showed a decrease followed by an increase of themartensite volume fraction Increase of the martensite content after annealing was relatedto carbide precipitation matrix carbon depletion and increasing of Ms temperature aboveroom temperature causing thermally induced martensite formation during cooling Thesample annealed at 800 C for 10 s exhibited the smallest average austenite grain size of240 nm with almost fully austenitic structure Tension test results for samples before andafter thermomechanical process showed a noticeable increase in yield strength from 452MPa to 966 Mpa and tensile strength from 815 Mpa to 1470 Mpa after process KeywordsMartensite reversion Nano submicron grain structure Austenitic stainless steels Thermomechanical treatment

عباس نجفي زاده ، احمد كرمانپور

فخرالدين اشرفي زاده ، محمد رضا طرقي نژاد