15040

13537

كارشناسي ارشد

شناسايي و انتخاب مواد

اصفهان : دانشگاه صنعتي اصفهان

1398

شانزده، 74ص. : مصور(رنگي)، جدول، نمودار

عبدالمجيد اسلامي، فخرالدين اشرفي زاده

فيروز فدائي فرد

محمدعلي گلعذار، ابوذر طاهري زاده

1398/06/25

كتابنامه

مهندسي مواد

مهندسي مواد

1398/06/25

2557795

75 Effect of heat treatment on microstructure mechanical and corrosion properties of 410NiMo alloy cladded by submerge arc welding on 21CrMoV5 11 sublayer Kazem abdian k abdian@ma iut ac ir June 23 2019 Department of Material Engineering Isfahan University of Technology Isfahan IranMSc language FarsiAbdoulmajid Eslami Assist Prof Supervisor Email m eslami@cc iut ac irFakherddin Ashrafizadeh Prof Supervisor Email f ashrafizadeh@cc iut ac irAbstractContinuous casting rollers are constantly degraded due to contact with hot slabs and the most suitablemethod for repairing them is the hardfacing process The 410NiMo steel is supermartensitic steelgrades which it has a good combination of mechanical and corrosion properties that applied inhardfacing process In the first step of this study failure analysis that was carried out on the rollerremoved from the service By considering the operation it was revealed that the deterioration factorsare mechanical and chemical Therefore the main purpose of this work is to study and compare theeffects of different heat treatments on mechanical properties hardness and impact and corrosion ofsuper martensitic stainless steel 410NiMo which used as a hard faced layer on these rollers Submerged arc welding process was used for applying hardfacing layer on the surface of continuouscasting rollers which are made of 21CrMoV5 11 steel After applying different thermal cycles 1 dissolution annealing treatment and 2 tempering scanning electron microscopy and opticalmicroscope vickers impact and corrosion tests were applied to the samples Microstructural studiesand X ray diffraction test showed that with increasing the temperature of austenite up to 1000 the percentage of Delta ferrite decreased whereas the residual austenite increased In the case of non heat treatment samples 440 HV hardness was achieved however in tempering one that was in 600 the minimum hardness was 318 HV The reason was due to the coarsening of carbides in themicrostructure The results of the Charpy test showed that the maximum impact energy 75 J wasassociated to the austenitic sample in 1000 while the lowest impact energy was 28 J in the Asweld sample Metallurgical observations proved that the lowest amount of Delta ferrite is in thesample that austentized in 1000 Fractography of samples by using scanning electron microscopyshowed that the failure mechanism in the As weld mode includes a combination of soft and brittlefracture but after annealing at 1000 the mechanism of failure is mainly soft fracture Thepotentiodynamic corrosion test in 0 05M K2SO4 0 05M NaCl showed that the tempered sample at600 C had the highest corrosion rate which could be due to the coarsening of carbides and thepresence of delta ferrite in the structure The lowest corrosion rate was related to austenitic samplesat 1000 and 1150 with the lowest percentage of delta ferrites and the highest amount ofaustenite phase Key Words Heat treatment continuous casting supermartensitic steel SAW

عبدالمجيد اسلامي، فخرالدين اشرفي زاده

فيروز فدائي فرد

محمدعلي گلعذار، ابوذر طاهري زاده