There are only few methods available for predicting the age of cracks that are found in high
temperature structural components during service; among the promising ones is the oxide
thickness measurement technique. Oxide thickness profiles are taken from crack surfaces of
components and used for predicting the rates of crack propagation. This technique is particularly
suitable for high temperature components fabricated from ferritic steels commonly used in power
plants that run on fossil fuels. To implement this technique, it is necessary to fully understand the
kinetics of high temperature oxidation in these steels. In this study, the oxidation characteristics
of an American Society of Testing and Materials (ASTM) Grade P91 ferritic steel used in high
temperature piping is characterized.
The literature shows that there are four primary mechanisms that influence the oxide thickness
during high temperature exposure. Initially, the oxide thickness increases in a linear fashion with
time and then as steady-state conditions are established, the parabolic relationship takes over.
Multiple types of oxides with different rate characteristics can also form. Oxide degradation can
occur by spallation due to porosity and formation of cracks. Evaporation or volatility can also
occur and result in loss of oxide thickness. These factors must be considered in oxide thickness
analysis to determine crack growth history.
Two sets of laboratory experiments were conducted. The first consisted of measurement of oxide
thicknesses after exposure to high temperature for various periods to determine the oxidation
kinetics. The oxidized samples were subjected to SEM examination and measurements of
physical properties such as density and porosity levels. The second set of experiments consisted
of measuring the oxide layer thickness on the fracture surfaces of creep-fatigue crack growth
samples tested as part of a previous study where the crack growth rates were measured. These
reported measurements are used to compare with the predicted crack growth rates from the
analytical models that are developed as part of this study. The success of the technique is
measured by finding the correlation coefficient, which is within a factor of 2.58.
","abstract_html":"<p>There are only few methods available for predicting the age of cracks that are found in high</p> <p>temperature structural components during service; among the promising ones is the oxide</p> <p>thickness measurement technique. Oxide thickness profiles are taken from crack surfaces of</p> <p>components and used for predicting the rates of crack propagation. This technique is particularly</p> <p>suitable for high temperature components fabricated from ferritic steels commonly used in power</p> <p>plants that run on fossil fuels. To implement this technique, it is necessary to fully understand the</p> <p>kinetics of high temperature oxidation in these steels. In this study, the oxidation characteristics</p> <p>of an American Society of Testing and Materials (ASTM) Grade P91 ferritic steel used in high</p> <p>temperature piping is characterized.</p> <p>The literature shows that there are four primary mechanisms that influence the oxide thickness</p> <p>during high temperature exposure. Initially, the oxide thickness increases in a linear fashion with</p> <p>time and then as steady-state conditions are established, the parabolic relationship takes over.</p> <p>Multiple types of oxides with different rate characteristics can also form. Oxide degradation can</p> <p>occur by spallation due to porosity and formation of cracks. Evaporation or volatility can also</p> <p>occur and result in loss of oxide thickness. These factors must be considered in oxide thickness</p> <p>analysis to determine crack growth history.</p> <p>Two sets of laboratory experiments were conducted. The first consisted of measurement of oxide</p> <p>thicknesses after exposure to high temperature for various periods to determine the oxidation</p> <p>kinetics. The oxidized samples were subjected to SEM examination and measurements of</p> <p>physical properties such as density and porosity levels. The second set of experiments consisted</p> <p>of measuring the oxide layer thickness on the fracture surfaces of creep-fatigue crack growth</p> <p>samples tested as part of a previous study where the crack growth rates were measured. These</p> <p>reported measurements are used to compare with the predicted crack growth rates from the</p> <p>analytical models that are developed as part of this study. The success of the technique is</p> <p>measured by finding the correlation coefficient, which is within a factor of 2.58.</p>","abstract_has_math":false,"creators":["Huneycutt, Ralph Edward, IV"],"institution":null,"degree_name":"Master of Science in Mechanical Engineering (MSME)","degree_level":"Thesis","degree_discipline":null,"degree_department":null,"school":null,"contributors":["Couvillion, Rick J.","Millett, Paul C."],"advisors":["Saxena, Ashok"],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-05-01T07:00:00Z","date_published":"2017-05-01T07:00:00Z","updated_at":"2026-07-24T00:59:24Z","subjects":["Fracture Mechanics","Oxidation","Oxidation Kinetics","P91 Steel","Predicting Crack Growth","Engineering Mechanics","Mechanical Engineering"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://scholarworks.uark.edu/etd/2028","outbound_label":"Repository record","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Couvillion, Rick J.","Millett, Paul C."]},{"key":"dc:contributor.advisor","label":"Advisor","values":["Saxena, Ashok"]},{"key":"dc:creator","label":"Author","values":["Huneycutt, Ralph Edward, IV"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2017"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2018-05-24T07:00:00Z"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science in Mechanical Engineering (MSME)"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Fracture Mechanics","Oxidation","Oxidation Kinetics","P91 Steel","Predicting Crack Growth","Engineering Mechanics","Mechanical Engineering"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["https://scholarworks.uark.edu/etd/2028"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["There are only few methods available for predicting the age of cracks that are found in high
temperature structural components during service; among the promising ones is the oxide
thickness measurement technique. Oxide thickness profiles are taken from crack surfaces of
components and used for predicting the rates of crack propagation. This technique is particularly
suitable for high temperature components fabricated from ferritic steels commonly used in power
plants that run on fossil fuels. To implement this technique, it is necessary to fully understand the
kinetics of high temperature oxidation in these steels. In this study, the oxidation characteristics
of an American Society of Testing and Materials (ASTM) Grade P91 ferritic steel used in high
temperature piping is characterized.
The literature shows that there are four primary mechanisms that influence the oxide thickness
during high temperature exposure. Initially, the oxide thickness increases in a linear fashion with
time and then as steady-state conditions are established, the parabolic relationship takes over.
Multiple types of oxides with different rate characteristics can also form. Oxide degradation can
occur by spallation due to porosity and formation of cracks. Evaporation or volatility can also
occur and result in loss of oxide thickness. These factors must be considered in oxide thickness
analysis to determine crack growth history.
Two sets of laboratory experiments were conducted. The first consisted of measurement of oxide
thicknesses after exposure to high temperature for various periods to determine the oxidation
kinetics. The oxidized samples were subjected to SEM examination and measurements of
physical properties such as density and porosity levels. The second set of experiments consisted
of measuring the oxide layer thickness on the fracture surfaces of creep-fatigue crack growth
samples tested as part of a previous study where the crack growth rates were measured. These
reported measurements are used to compare with the predicted crack growth rates from the
analytical models that are developed as part of this study. The success of the technique is
measured by finding the correlation coefficient, which is within a factor of 2.58.
"]},{"key":"dc:title","label":"Title","values":["Feasibility of Using Oxide Thickness Measurements for Predicting Crack Growth Rates in P91 Steel Components"]}]}],"canonical_facts":{"dc:contributor":["Couvillion, Rick J.","Millett, Paul C."],"dc:contributor.advisor":["Saxena, Ashok"],"dc:creator":["Huneycutt, Ralph Edward, IV"],"dc:date":["2017"],"dc:date.available":["2018-05-24T07:00:00Z"],"dc:description.abstract":["There are only few methods available for predicting the age of cracks that are found in high
temperature structural components during service; among the promising ones is the oxide
thickness measurement technique. Oxide thickness profiles are taken from crack surfaces of
components and used for predicting the rates of crack propagation. This technique is particularly
suitable for high temperature components fabricated from ferritic steels commonly used in power
plants that run on fossil fuels. To implement this technique, it is necessary to fully understand the
kinetics of high temperature oxidation in these steels. In this study, the oxidation characteristics
of an American Society of Testing and Materials (ASTM) Grade P91 ferritic steel used in high
temperature piping is characterized.
The literature shows that there are four primary mechanisms that influence the oxide thickness
during high temperature exposure. Initially, the oxide thickness increases in a linear fashion with
time and then as steady-state conditions are established, the parabolic relationship takes over.
Multiple types of oxides with different rate characteristics can also form. Oxide degradation can
occur by spallation due to porosity and formation of cracks. Evaporation or volatility can also
occur and result in loss of oxide thickness. These factors must be considered in oxide thickness
analysis to determine crack growth history.
Two sets of laboratory experiments were conducted. The first consisted of measurement of oxide
thicknesses after exposure to high temperature for various periods to determine the oxidation
kinetics. The oxidized samples were subjected to SEM examination and measurements of
physical properties such as density and porosity levels. The second set of experiments consisted
of measuring the oxide layer thickness on the fracture surfaces of creep-fatigue crack growth
samples tested as part of a previous study where the crack growth rates were measured. These
reported measurements are used to compare with the predicted crack growth rates from the
analytical models that are developed as part of this study. The success of the technique is
measured by finding the correlation coefficient, which is within a factor of 2.58.
"],"dc:identifier":["https://scholarworks.uark.edu/etd/2028"],"dc:subject":["Fracture Mechanics","Oxidation","Oxidation Kinetics","P91 Steel","Predicting Crack Growth","Engineering Mechanics","Mechanical Engineering"],"dc:title":["Feasibility of Using Oxide Thickness Measurements for Predicting Crack Growth Rates in P91 Steel Components"],"thesis:degree_level":["Thesis"],"thesis:degree_name":["Master of Science in Mechanical Engineering (MSME)"]},"updated_at":"2026-07-24T00:59:24Z"}