東華大學圖書館 |

語系: 繁體中文

說明(常見問題)

回圖書館首頁

手機版館藏查詢

登入

回首頁

切換: 標籤 | MARC模式 | ISBD

FindBook

Google Book

Amazon

博客來

Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels.

紀錄類型:	書目-電子資源 : Monograph/item
正題名/作者:	Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels./
作者:	Peterson, Andrew.
出版者:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
面頁冊數:	182 p.
附註:	Source: Dissertations Abstracts International, Volume: 83-03, Section: B.
Contained By:	Dissertations Abstracts International83-03B.
標題:	Materials science. -
電子資源:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28547387
ISBN:	9798538121649

Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels.
Peterson, Andrew.

Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 182 p.

Source: Dissertations Abstracts International, Volume: 83-03, Section: B.

Thesis (Ph.D.)--Dartmouth College, 2021.

This item must not be sold to any third party vendors.

Alumina-forming austenitic stainless steels (AFAs) are a class of steel being developed for use in high temperature and corrosive conditions. AFAs show great promise to operate under these conditions; however, the deformation behavior is poorly understood, which limits the optimization of the mechanical properties. This dissertation seeks to understand the deformation behavior of the model AFA alloy Fe-20Cr-30Ni-2Nb-5Al at high temperatures.First, the microstructural evolution was investigated during creep at 750°C. The creep rate was found to correlate with changes in the microstructure. Significant strengthening from nano-sized L12-structured precipitates nucleating in the matrix initially reduced the creep rate. At longer creep times, a coarsening of precipitates along with the formation of a wide precipitate free zone (PFZ) resulted in an increased creep rate.Next, the formation mechanism, growth, and mechanical properties of the L12 PFZ were studied. It is shown that a PFZ forms both around the GBs and near large matrix precipitates due to solute depletion resulting in the dissolution of L12 precipitates. The growth of the PFZ can be modeled well with the diffusion of Ni through the matrix. Micro-cracks observed in the PFZ of crept samples indicate that the PFZ is softer than the surrounding L12-strengthened matrix and is likely where failure initiates during creep.The high temperature deformation mechanisms were then investigated using both creep tests and strain rate jump tests. This work confirmed that the L12 precipitates were the dominant precipitate in the matrix and provided the majority of the strengthening. Additionally, a grain boundary (GB) strengthening mechanism in which the GBs covered by precipitates act as barriers to dislocation movement and prevent GB sliding during creep was observed.Finally, machine learning and advanced data analytics techniques were applied to AFA creep data to gain new insights into alloy design and to ultimately gauge the prospects of using machine learning models to improve alloy design. While these models show promise in predicting creep properties based on alloy composition, they are not yet practical for alloy design without an improved dataset.

ISBN: 9798538121649Subjects--Topical Terms:

543314
Materials science.
Subjects--Index Terms:

Creep rate

Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels.
LDR:03483nmm a2200409 4500 001 2347626
005 20220823142315.5
008 241004s2021 ||||||||||||||||| ||eng d
020 $a 9798538121649
035 $a (MiAaPQ)AAI28547387
035 $a AAI28547387
040 $a MiAaPQ $c MiAaPQ
100 1 $a Peterson, Andrew. $3 1674696
245 1 0 $a Understanding the Deformation Behavior of Alumina-Forming Austenitic Stainless Steels.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2021
300 $a 182 p.
500 $a Source: Dissertations Abstracts International, Volume: 83-03, Section: B.
500 $a Advisor: Baker, Ian.
502 $a Thesis (Ph.D.)--Dartmouth College, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a Alumina-forming austenitic stainless steels (AFAs) are a class of steel being developed for use in high temperature and corrosive conditions. AFAs show great promise to operate under these conditions; however, the deformation behavior is poorly understood, which limits the optimization of the mechanical properties. This dissertation seeks to understand the deformation behavior of the model AFA alloy Fe-20Cr-30Ni-2Nb-5Al at high temperatures.First, the microstructural evolution was investigated during creep at 750°C. The creep rate was found to correlate with changes in the microstructure. Significant strengthening from nano-sized L12-structured precipitates nucleating in the matrix initially reduced the creep rate. At longer creep times, a coarsening of precipitates along with the formation of a wide precipitate free zone (PFZ) resulted in an increased creep rate.Next, the formation mechanism, growth, and mechanical properties of the L12 PFZ were studied. It is shown that a PFZ forms both around the GBs and near large matrix precipitates due to solute depletion resulting in the dissolution of L12 precipitates. The growth of the PFZ can be modeled well with the diffusion of Ni through the matrix. Micro-cracks observed in the PFZ of crept samples indicate that the PFZ is softer than the surrounding L12-strengthened matrix and is likely where failure initiates during creep.The high temperature deformation mechanisms were then investigated using both creep tests and strain rate jump tests. This work confirmed that the L12 precipitates were the dominant precipitate in the matrix and provided the majority of the strengthening. Additionally, a grain boundary (GB) strengthening mechanism in which the GBs covered by precipitates act as barriers to dislocation movement and prevent GB sliding during creep was observed.Finally, machine learning and advanced data analytics techniques were applied to AFA creep data to gain new insights into alloy design and to ultimately gauge the prospects of using machine learning models to improve alloy design. While these models show promise in predicting creep properties based on alloy composition, they are not yet practical for alloy design without an improved dataset.
590 $a School code: 0059.
650 4 $a Materials science. $3 543314
650 4 $a Engineering. $3 586835
650 4 $a Thermodynamics. $3 517304
650 4 $a Nanoscience. $3 587832
653 $a Creep rate
653 $a Microstructure
653 $a Precipitate Free Zone
653 $a Precipitates
653 $a Deformation behavior
653 $a Alumina
653 $a Austenitic stainless steels
690 $a 0794
690 $a 0565
690 $a 0537
690 $a 0348
710 2 $a Dartmouth College. $b Engineering. $3 1057396
773 0 $t Dissertations Abstracts International $g 83-03B.
790 $a 0059
791 $a Ph.D.
792 $a 2021
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28547387