Austenite grain growth studies in line pipe steels
department or school: Applied Science, Faculty of
department or school: Materials Engineering, Department of
data provider: DSpace
degree campus: UBCV
creator: Swan, Joshua
issued: 2024-07-08T19:53:38Z
issued: 2024
related degree: Master of Applied Science - MASc
degree grantor: University of British Columbia
description: The oil and natural gas industry, as well as newly developing technologies such as carbon sequestration and hydrogen transport rely on pipelines for transportation of their products. As the demand for safety and efficiency of pipelines increase, the properties of the line pipe steel from which they are made must improve. To do this, line pipe steel is manufactured using a thermomechanically controlled process (TMCP) which combines specific alloying elements with processing conditions to produce an engineered microstructure. Within the TMCP, the austenite grain size and structure are important factors in determining the final microstructure and thus mechanical properties. The purpose of this work is to investigate the austenite grain growth evolution during the thermal treatment in the reheat furnace and compare austenite grain growth characteristics in as-cast slab and hot-rolled material. Two different line pipe steels with varying amounts of manganese and niobium were studied. Thermal conditions were simulated with a Gleeble 3500 thermomechanical simulator while the austenite grain size was measured in-situ with a laser ultrasonics for metallurgy (LUMet) system. The reheat furnace treatment was simulated with a slow heating rate of 5°C/min to 1200°C followed by a 2hr hold. Grain growth comparison experiments consisted of a high heating rate of 50°C/s to one of three holding temperatures of 1100°C, 1200°C and 1300°C. Results of the LUMet measurements were validated by reconstructions of prior-austenite microstructures using electron backscatter diffraction (EBSD) data. LUMet measurements and reconstructions of austenite grain structures for the as-cast slab material undergoing the reheat furnace simulation show a bimodal grain size distribution with a few extremely large grains and many small grains clustered together. A similar but less extreme version of this microstructure was found in slab material undergoing grain growth comparison experiments. This bimodal mi…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/88593
note: Austenite Grain Growth Studies in Line Pipe Steels by Joshua Swan B.A.Sc., The University of British Columbia, 2021 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF APPLIED SCIENCE in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Materials Engineering) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) July 2024 © Joshua Swan, 2024 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the thesis entitled: Austenite Grain Growth Studies in Line Pipe Steels submitted by Joshua Swan in partial fulfilment of the requirements for the degree of Master of Applied Science in Materials Engineering Examining Committee: Matthias Militzer, Professor, Department of Materials Engineering, UBC Supervisor Warren J. Poole, Professor, Department of Materials Engineering, UBC Co-supervisor Edouard Asselin, Professor, Department of Materials Engineering, UBC Supervisory Committee Member Sergey Kravchenko, Associate Professor, Department of Materials Engineering, UBC Supervisory Committee Member iii Abstract The oil and natural gas industry, as well as newly developing technologies such as carbon sequestration and hydrogen transport rely on pipelines for transportation of their products. As the demand for safety and efficiency of pipelines increase, the properties of the line pipe steel from which they are made must improve. To do this, line pipe steel is manufactured using a thermomechanically controlled process (TMCP) which combines specific alloying elements with processing conditions to produce an engineered microstructure. Within the TMCP, the austenite grain size and structure are important factors in determining the final microstructure and thus mechanical properties. The purpose of this work is to investigate the austenite grain growth evolution during the thermal treatment in the reheat furnace and compare austenite grain growth characteristics in as-ca…
has type: Thesis/Dissertation
date issued: 2024-11
is shown at: 10.14288/1.0444108
language: eng
degree discipline: Materials Engineering
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Militzer, Matthias
contributor: Poole, W. J. (Warren J.)
type: Text
identifier URI: http://hdl.handle.net/2429/88593