Sökning: "martensitic steel"

Visar resultat 1 - 5 av 61 avhandlingar innehållade orden martensitic steel.

  1. 1. Deposit Induced Corrosion in Biofuel Combustion

    Författare :Petter Andersson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferritic steel; high temperature corrosion; superheater; waste combustion; CFB; biofuel boiler; waterwall; alkali chloride; deposit induced corrosion; chromate; nickel-based alloy; austenitic steel; martensitic steel; waste boiler;

    Sammanfattning : Deposit induced corrosion is one of the main mechanisms for attack on heat exchangers in biofuel boilers. This severe corrosion decreases the obtainable steam temperature in boilers, thereby the efficiency in production of electricity is reduced. Deposit formation from the gas on superheater tubes are is generally referred to as fouling. LÄS MER

  3. 2. High-Temperature Durability Prediction of Ferritic-Martensitic Steel

    Författare :Ahmed Azeez; Robert Eriksson; Kjell Simonsson; Daniel Leidermark; Christer Persson; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ferritic-martensitic steel; Low cycle fatigue; Thermomechanical fatigue; Crack propagation; Fracture mechanics; Finite element modelling;

    Sammanfattning : Materials used for high-temperature steam turbine sections are generally subjected to harsh environments with temperatures up to 625 °C. The superior creep resistance of 9–12 % Cr ferritic-martensitic steels makes them desirable for those critical steam turbine components. LÄS MER

  4. 3. Micro-mechanical FE-simulations of the plastic behaviour of steels undergoing martensitic transformation

    Författare :Kjell Simonsson; Sören Sjöström; Marcel Berveiller; Linköpings universitet; []
    Nyckelord :Steel; martensitic transformation; grain constitution; finite element simulations; plastic behaviour; transformation kinetics; TECHNOLOGY; TEKNIKVETENSKAP;

    Sammanfattning : This thesis is concerned with the mechanical behaviour of steels undergoing martensitic transformation. More specifically, the aim has been to develop a method to numerically stimulate the mean strain (or stress) response associated with a prescribed temperature and mean stress (or strain) variation. LÄS MER

  5. 4. Modeling the Microstructure Evolution During and After Hot Working in Martensitic Steel

    Författare :Nima Safara Nosar; John Ågren; Göran Engberg; Hans-Olof Andrén; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modeling; Martensitic steel; Carbides; Carbide size distribution; Carbide volume fraction; Carbide shape factor; Modellering; Martensitiskt stål; karbider; karbidstorleksfördelning; karbidvolymfraktion; karbidformfaktor; Teknisk materialvetenskap; Materials Science and Engineering;

    Sammanfattning : In this study, the goal is to predict the microstructure evolution during and after the hot working of a martensitic stainless steel with 13% chromium using a physically-based model in the form of a MATLAB toolbox. This model is based on dislocation density theory and consists of coupled sets of evolution equations for dislocation, vacancies, recovery, recrystallization, and grain growth. LÄS MER

  7. 5. White Layer Formation during Hard Turning of Through-Hardened Martensitic and Bainitic AISI 52100 Steel

    Författare :Seyed Hosseini; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; white layers; residual stresses; phase transformation; dynamic recovery; bainite; dynamic recrystallization; carbide deformation; retained austenite; steel; martensite;

    Sammanfattning : Increased demands for flexible manufacturing lines, shorter cycle times and reduced impact on the environment drives the need for optimization of today’s manufacturing. For machining of hardened steel parts (>45 HRC), grinding has been the obvious choice for many decades. However, hard turning has often been considered as a replacement due to e. LÄS MER