國立虎尾科技大學 |

A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels./
Author:	Wang, Yuankang.
Published:	Ann Arbor : ProQuest Dissertations & Theses, : 2021,
Description:	84 p.
Notes:	Source: Masters Abstracts International, Volume: 82-09.
Contained By:	Masters Abstracts International82-09.
Subject:	Engineering. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28390732
ISBN:	9798569958771

A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels.
Wang, Yuankang.

A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels. - Ann Arbor : ProQuest Dissertations & Theses, 2021 - 84 p.

Source: Masters Abstracts International, Volume: 82-09.

Thesis (M.S.)--University of Pittsburgh, 2021.

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

This study compares the Austenite Grain Growth Behavior and its Transformation Behavior during the uniform Continuous Cooling of a Selective Laser Melting (SLM) 4340 and conventional Wrought 4340 steels. SLM 4340 steels exhibit inferior mechanical properties then conventional Wrought 4340 steels. Hence, the effect of hot deformation on the final microstructure and mechanical properties of SLM 4340 steel were also investigated in this study. Standard dilatometry testing was used to study the Austenite decomposition behavior at different cooling rates and to develop the CCT diagrams. Hot Compression Testing was performed to investigate the effect of hot deformation on the microstructure of austenite for both systems SLM 4340 and Wrought 4340. Advanced microstructural characterization techniques, Scanning Electron Microscopy (SEM) and Orientation Imaging Microscopy (OIM) were employed to support the CCT diagrams. Electron Backscatter Diffraction (EBSD) and a special EBSD-IQ characterization technique were used to assess the percentage of the microstructural components observed. Three important observations were made: 1) the hardenability of the Wrought 4340 steel was higher than the SLM 4340 steel; 2) the presence of Granular Bainite was observed after slow cooling conditions in both steels. MTEXT, a MatLab program, was used to reconstruct the prior Austenite grains (PAG). The SLM steel exhibited finer Austenite grain size distribution than the Wrought steel in the temperature range studied; and 3) the porosity in SLM 4340 was closed during the hot compression tests improving its mechanical properties. The level of microstructural refinement of austenite after hot deformation was measured by the effective interfacial area per unit volume (Sv) parameter for the SLM 4340 and Wrought 4340 steels.

ISBN: 9798569958771Subjects--Topical Terms:

561152
Engineering.
Subjects--Index Terms:

Transformation behavior

A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels.
LDR:03121nam a2200373 4500 001 1067169
005 20220823142307.5
008 221020s2021 ||||||||||||||||| ||eng d
020 $a 9798569958771
035 $a (MiAaPQ)AAI28390732
035 $a (MiAaPQ)Pittsburgh39890
035 $a AAI28390732
040 $a MiAaPQ $c MiAaPQ
100 1 $a Wang, Yuankang. $3 1372527
245 1 0 $a A Comparison Study of the Transformation Behavior during Uniform Continuous Cooling and Hot Deformation Characteristics of a Wrought and Selective Laser Melting 4340 Steels.
260 1 $a Ann Arbor : $b ProQuest Dissertations & Theses, $c 2021
300 $a 84 p.
500 $a Source: Masters Abstracts International, Volume: 82-09.
500 $a Advisor: Garcia, C. Isaac.
502 $a Thesis (M.S.)--University of Pittsburgh, 2021.
506 $a This item must not be sold to any third party vendors.
520 $a This study compares the Austenite Grain Growth Behavior and its Transformation Behavior during the uniform Continuous Cooling of a Selective Laser Melting (SLM) 4340 and conventional Wrought 4340 steels. SLM 4340 steels exhibit inferior mechanical properties then conventional Wrought 4340 steels. Hence, the effect of hot deformation on the final microstructure and mechanical properties of SLM 4340 steel were also investigated in this study. Standard dilatometry testing was used to study the Austenite decomposition behavior at different cooling rates and to develop the CCT diagrams. Hot Compression Testing was performed to investigate the effect of hot deformation on the microstructure of austenite for both systems SLM 4340 and Wrought 4340. Advanced microstructural characterization techniques, Scanning Electron Microscopy (SEM) and Orientation Imaging Microscopy (OIM) were employed to support the CCT diagrams. Electron Backscatter Diffraction (EBSD) and a special EBSD-IQ characterization technique were used to assess the percentage of the microstructural components observed. Three important observations were made: 1) the hardenability of the Wrought 4340 steel was higher than the SLM 4340 steel; 2) the presence of Granular Bainite was observed after slow cooling conditions in both steels. MTEXT, a MatLab program, was used to reconstruct the prior Austenite grains (PAG). The SLM steel exhibited finer Austenite grain size distribution than the Wrought steel in the temperature range studied; and 3) the porosity in SLM 4340 was closed during the hot compression tests improving its mechanical properties. The level of microstructural refinement of austenite after hot deformation was measured by the effective interfacial area per unit volume (Sv) parameter for the SLM 4340 and Wrought 4340 steels.
590 $a School code: 0178.
650 4 $a Engineering. $3 561152
650 4 $a Materials science. $3 557839
653 $a Transformation behavior
653 $a Uniform continuous cooling
653 $a Hot deformation characteristics
653 $a Wrought and selective laser melting
653 $a 4340 Steels
690 $a 0794
690 $a 0537
710 2 $a University of Pittsburgh. $3 1178873
773 0 $t Masters Abstracts International $g 82-09.
790 $a 0178
791 $a M.S.
792 $a 2021
793 $a English
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=28390732