Characterization of transition carbides in quench and partitioned steel microstructures by Mössbauer spectroscopy and complementary techniques
Journal Article
·
· Acta Materialia
- Colorado School of Mines, Golden, CO (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Quenching and partitioning (Q&P) produces steel microstructures with martensite and austenite that exhibit promising property combinations for third generation advanced high strength steels. Understanding the kinetics of reactions that compete for available carbon, such as carbide formation, is critical for alloying and processing design and achieving austenite enrichment and retention during Q&P. Mössbauer effect spectroscopy (MES) was used to characterize Q&P microstructures in a 0.38C-1.54Mn-1.48Si wt.% steel after quenching to 225 °C and partitioning at 400 °C for 10 or 300 s, with an emphasis on transition carbides. The recoilless fraction for η-carbide was calculated and a correction for saturation of the MES absorption spectrum was applied, making quantitative measurements of small amounts of η-carbide, including non-stoichiometric η-carbide, possible in Q&P microstructures. Complementary transmission electron microscopy confirmed the presence of η-carbides, and MES and X-ray diffraction were used to characterize the austenite. The amount of η-carbide formed during Q&P ranged from 1.4 to 2.4 at.%, accounting for a substantial portion (~24% to 41%) of the bulk carbon content of the steel. The amount (5.0 at.%) of η-carbide that formed after quenching and tempering (Q&T) at 400 °C for 300 s was significantly greater than after partitioning at 400 °C for 300 s (2.4 at.%), suggesting that carbon partitioning from martensite to austenite occurs in conjunction with η-carbide formation during Q&P in these specimens.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- AC52-06NA25396; EE0005765
- OSTI ID:
- 1193479
- Alternate ID(s):
- OSTI ID: 22452950
OSTI ID: 1432139
- Report Number(s):
- LA-UR--14-28509; PII: S1359645415000282
- Journal Information:
- Acta Materialia, Journal Name: Acta Materialia Journal Issue: C Vol. 90; ISSN 1359-6454
- Publisher:
- ElsevierCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
Quantitative investigation into the influence of temperature on carbide and austenite evolution during partitioning of a quenched and partitioned steel
Microstructural evolution during quenching and partitioning of 0.2C-1.5Mn-1.3Si steels with Cr or Ni additions
Perspectives on Quenching and Tempering 4340 Steel
Journal Article
·
Mon May 02 20:00:00 EDT 2016
· Scripta Materialia
·
OSTI ID:1357998
Microstructural evolution during quenching and partitioning of 0.2C-1.5Mn-1.3Si steels with Cr or Ni additions
Journal Article
·
Wed Mar 07 19:00:00 EST 2018
· Acta Materialia
·
OSTI ID:1435324
Perspectives on Quenching and Tempering 4340 Steel
Journal Article
·
Wed Aug 26 20:00:00 EDT 2020
· Metallurgical and Materials Transactions. A, Physical Metallurgy and Materials Science
·
OSTI ID:1657929