Essays about: "Sigma-phase"

Showing result 1 - 5 of 10 essays containing the word Sigma-phase.

  1. 1. Optimization of the process-route of a Nickel-base alloy : Investigation of Sigma-phase precipitation in heat treatment

    University essay from Karlstads universitet/Fakulteten för hälsa, natur- och teknikvetenskap (from 2013)

    Author : Felix Andersson; [2023]
    Keywords : Sigma-phase; austenitic stainless steel; Nickel-base alloy; heat treatment; Sigmafas; austenitiskt rostfritt stål; Nickelbas legering; värmebehandling;

    Abstract : The focus of this master’s thesis is on the heat treatment of Ni-base alloys, specifically the risk of intermetallic σ-phases during different stages of heat treatment. The alloy studied is Sanicro®28, a super-austenitic stainless steel produced by Alleima AB. READ MORE

  3. 2. Ab inito calculation of the formation energy of the sigma phases at 1000 Kelvin : With a five sublattice model for the ternary Iron-Chromium-Nickel system

    University essay from KTH/Materialvetenskap

    Author : Fabian Mathias Veid; [2022]
    Keywords : ;

    Abstract : This project investigates the σ-phase formation energy at 1000 Kelvin using Exact Muffin TIn Orbital (EMTO) method and considers the disordered local moment approach to handle the paramagnetism in a self-consistent manner. The sigma phase is detrimental and causes embrittlement when it occurs primarily in stainless steel and superalloys with Iron (Fe) and Chromium (Cr), which is why it is necessary to understand it better and therefore avoid it. READ MORE

  4. 3. Microstructural characterization of quench annealed duplex SAF 2507 utilizing EBSD

    University essay from Uppsala universitet/Tillämpad materialvetenskap

    Author : Simon Beyermann; [2022]
    Keywords : sigma phase; chi phase; electron backscatter diffraction; super duplex stainless steel; recrystallization; SAF 2507 UNS S32750 .;

    Abstract : Producing large bars of duplex stainless steel free from precipitated embrittling phases isdifficult due to the many factors that influence precipitation. Research shows that intermetallicslike sigma and chi deteriorate principal material properties for the main application areas. READ MORE

  5. 4. Long term aging and creep exposure for advanced heat resistant alloys : A phase analysis

    University essay from Uppsala universitet/Institutionen för materialvetenskap; Uppsala universitet/Institutionen för kemi - Ångström

    Author : Daniel Lundberg; Filip Wilson; Hjalmar Gunnarsson; Leo Sjörén; Robin Xu; Erik Djurberg; [2021]
    Keywords : Austenitic stainless steel; ferritic steels; nickel based alloys; creep; ageing; XRD; SEM EDS; LOM;

    Abstract : This project was ordered by Sandvik Materials Technology and was performed by a group of students at Uppsala university. The purpose of the project was to study precipitation behavior and structure stability in six advanced heat resistant alloys. Each sample were subjected to a creep rupture test in 600 or 700°C depending on the alloy type. READ MORE

  6. 5. Combined CALPHAD and Machine Learning for Property Modelling

    University essay from KTH/Materialvetenskap

    Author : Kyle Paulus; [2020]
    Keywords : ;

    Abstract : Techniques to improve the speed at which materials are researched and developed has been conducted by investigating the machine learning methodology. These techniques offer solutions to connect the length scales of material prop- erties from atomistic and chemical features using materials databases generated from collected data. READ MORE