Development of thermo-mechanical processing to form high density of uniformly distributed nanosized carbides in austenitic stainless steels

Ji Ho Shin, Ho Sub Kim, Byeong Seo Kong, Gokul Obulan Subramanian, Sunghoon Hong, Ho Jung Lee, Changheui Jang

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

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 languageEnglish
Article number138986
JournalMaterials Science and Engineering A
Volume775
DOIs
Publication statusPublished - 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

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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