Abstract
Model alloys and thermomechanical processing (TMP) were developed to form a high density of uniformly distributed nanosized (<10 nm) carbides in an austenitic stainless steel matrix. The composition of the model alloys was determined to control the formation of precipitates during the TMP. The TMP consisted of homogenization at 1200 °C for 1 h, multiple hot-rolling passes above and below the non-recrystallization temperature (TNR), and precipitation heat treatment at 800 °C for 2 h. By proper division of the rolling passes above and below TNR, a microstructure with a homogeneous grain size and a well-developed dislocation structure was obtained. Then, subsequent precipitation heat treatment produced a microstructure containing a high density (~1.1 × 1022/m3) of uniformly distributed and coherent NbC precipitates in the austenitic matrix. The evolution of the nanosized NbC during the precipitation heat treatment was coupled with the dislocation characteristics, such as the density and distribution, which were controlled by the hot-rolling conditions.
Original language | English |
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Article number | 138986 |
Journal | Materials Science and Engineering A |
Volume | 775 |
DOIs | |
Publication status | Published - 21 Feb 2020 |
Bibliographical note
Funding Information:This study was mainly supported by the NRF (National Research Foundation) of the MSIT (Ministry of Science and ICT) (Engineering Research Center No. 2016R1A5A1013919) of the Republic of Korea. Financial support for two of the authors was provided by the BK-Plus Program of the MSIT of the Republic of Korea. Authors appreciate POSCO for helping with the manufacturing of ingots. In addition, we are very grateful to Mr. Hyungbin Bae and Jinseok Choi of KAIST Analysis Center for Research Advancement (KARA) for helping with the TEM analysis.
Funding Information:
This study was mainly supported by the NRF (National Research Foundation) of the MSIT (Ministry of Science and ICT) (Engineering Research Center No. 2016R1A5A1013919 ) of the Republic of Korea. Financial support for two of the authors was provided by the BK-Plus Program of the MSIT of the Republic of Korea. Authors appreciate POSCO for helping with the manufacturing of ingots. In addition, we are very grateful to Mr. Hyungbin Bae and Jinseok Choi of KAIST Analysis Center for Research Advancement (KARA) for helping with the TEM analysis.
Publisher Copyright:
© 2020 Elsevier B.V.
Keywords
- Austenitic stainless steel
- Coherency
- Dislocation
- Nanosized precipitate
- Thermomechanical processing
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering