Study of the kinetics of precipitation, dissolution and coarsening of aluminum nitride in low carbon steels
department or school: Applied Science, Faculty of
department or school: Materials Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Cheng, Leon Man Lung
issued: 2009-06-29T23:03:23Z
issued: 1999
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Owing to its significant effect on grain growth and recrystallization, both of which directly influence hardenability, ductility, texture formation and the mechanical properties of steels, the precipitation behavior of aluminum nitride (A1N) in steels is becoming of increasing practical importance. To improve the current understanding of the mechanisms and kinetics of precipitation, dissolution, growth and coarsening of A1N during the thermomechanical processing of low carbon steels, a comprehensive experimental and theoretical study has been carried out. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have been used, with the aid of the carbon extraction replica technique, to relate the observed morphologies, spatial distribution and particle size distribution of A1N precipitates in a low carbon, Al-killed steel to their thermal history. Experimental studies have been conducted on the precipitation, dissolution, growth and coarsening of A1N precipitates during isothermal annealing, reheating or continuous cooling of the steel at 650°C to 1350°C. The influence of prestraining on the kinetics of isothermal precipitation of A1N has also been studied using the Gleeble 1500 thermomechanical simulator and the stress relaxation technique. Generalized, theoretically based models have been developed in the present project to predict the kinetics of precipitation, dissolution, growth and coarsening of nitrides or carbides in low carbon or microalloyed steels undergoing thermomechanical treatments. The precipitation model takes into account the equilibrium thermodynamic properties of the systems, the precipitate morphology, the misfit strain energy (coherent or incoherent) and the interfacial energy. The precipitation kinetics is formulated using classical nucleation and growth theories. Both homogeneous and heterogeneous nucleation are considered. In the present work, the model is applied to study the precipitation behavior of A1N …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/9845
extent: 20779927 bytes
format: application/pdf
note: STUDY OF THE KINETICS OF PRECIPITATION, DISSOLUTION AND COARSENING OF ALUMINUM NITRIDE IN LOW CARBON STEELS by LEON MAN LUNG CHENG M.Sc, University of California at Berkeley, 1992 B.Sc., National Taiwan University, 1990 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE STUDIES (DEPARTMENT OF METALS AND MATERIALS ENGINEERING) We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA April, 1999 ©Leon Cheng, 1999 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department The University of British Columbia Vancouver, Canada DE-6 (2/88) 11 ABSTRACT Owing to its significant effect on grain growth and recrystallization, both of which directly influence hardenability, ductility, texture formation and the mechanical properties of steels, the precipitation behavior of aluminum nitride (A1N) in steels is becoming of increasing practical importance. To improve the current understanding of the mechanisms and kinetics of precipitation, dissolution, growth and coarsening of A1N during the thermomechanical processing of low carbon steels, a comprehensive experimental and theoretical study has been carried out. Transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have been used, with the aid of the carbon extraction replica technique, to relate the observed morphologies, spatial distribution and particle size distribution of A1N precipitates in a low carbon, Al-killed steel …
has type: Thesis/Dissertation
date issued: 1999-05
is shown at: 10.14288/1.0078633
language: eng
degree discipline: Materials Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/9845