Austenite reversion in low-carbon martensitic stainless steels – a CALPHAD-assisted review

Frank Niessen*

*Corresponding author for this work

Research output: Contribution to journalJournal articleResearchpeer-review

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Abstract

Low-carbon martensitic stainless steels with 11.5–16 wt-% Cr and < 0.07 wt-% C are characterised by high corrosion resistance, strength, ductility and impact toughness, obtained by formation of fine-grained reverted austenite from lath martensite upon inter-critical annealing. The review treats the mechanisms governing the formation and stabilisation of reverted austenite and is assisted by the computation of phase equilibria. Literature data on Cr and Ni concentrations of the reverted austenite/martensite dual-phase microstructure are assessed with respect to predicted concentrations. Reasonable agreement was found for concentrations in martensite. Systematic excess of Cr in austenite of approx. 2 wt-% relative to calculations was suspected to originate from the growth of M23C6 with a coherent interface to austenite. Within large scatter, measured values of Ni in austenite were on average 2 wt-% below predictions. Complex equilibration of the microstructure and experimental error are discussed as possible origins of the discrepancies.
Original languageEnglish
JournalMaterials Science and Technology
Volume34
Issue number12
Pages (from-to)1401-1414
ISSN0267-0836
DOIs
Publication statusPublished - 2018

Keywords

  • Austenite reversion
  • Microstructure evolution
  • Solute partitioning
  • Thermodynamics
  • CALPHAD
  • Diffusion
  • Martensite formation
  • Residual stress

Cite this

@article{73c233b0e15f46b3a6cd143ad7d7fa8a,
title = "Austenite reversion in low-carbon martensitic stainless steels – a CALPHAD-assisted review",
abstract = "Low-carbon martensitic stainless steels with 11.5–16 wt-{\%} Cr and < 0.07 wt-{\%} C are characterised by high corrosion resistance, strength, ductility and impact toughness, obtained by formation of fine-grained reverted austenite from lath martensite upon inter-critical annealing. The review treats the mechanisms governing the formation and stabilisation of reverted austenite and is assisted by the computation of phase equilibria. Literature data on Cr and Ni concentrations of the reverted austenite/martensite dual-phase microstructure are assessed with respect to predicted concentrations. Reasonable agreement was found for concentrations in martensite. Systematic excess of Cr in austenite of approx. 2 wt-{\%} relative to calculations was suspected to originate from the growth of M23C6 with a coherent interface to austenite. Within large scatter, measured values of Ni in austenite were on average 2 wt-{\%} below predictions. Complex equilibration of the microstructure and experimental error are discussed as possible origins of the discrepancies.",
keywords = "Austenite reversion, Microstructure evolution, Solute partitioning, Thermodynamics, CALPHAD, Diffusion, Martensite formation, Residual stress",
author = "Frank Niessen",
year = "2018",
doi = "10.1080/02670836.2018.1449179",
language = "English",
volume = "34",
pages = "1401--1414",
journal = "Materials Science and Technology",
issn = "0267-0836",
publisher = "CRC Press/Balkema",
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}

Austenite reversion in low-carbon martensitic stainless steels – a CALPHAD-assisted review. / Niessen, Frank.

In: Materials Science and Technology, Vol. 34, No. 12, 2018, p. 1401-1414 .

Research output: Contribution to journalJournal articleResearchpeer-review

TY - JOUR

T1 - Austenite reversion in low-carbon martensitic stainless steels – a CALPHAD-assisted review

AU - Niessen, Frank

PY - 2018

Y1 - 2018

N2 - Low-carbon martensitic stainless steels with 11.5–16 wt-% Cr and < 0.07 wt-% C are characterised by high corrosion resistance, strength, ductility and impact toughness, obtained by formation of fine-grained reverted austenite from lath martensite upon inter-critical annealing. The review treats the mechanisms governing the formation and stabilisation of reverted austenite and is assisted by the computation of phase equilibria. Literature data on Cr and Ni concentrations of the reverted austenite/martensite dual-phase microstructure are assessed with respect to predicted concentrations. Reasonable agreement was found for concentrations in martensite. Systematic excess of Cr in austenite of approx. 2 wt-% relative to calculations was suspected to originate from the growth of M23C6 with a coherent interface to austenite. Within large scatter, measured values of Ni in austenite were on average 2 wt-% below predictions. Complex equilibration of the microstructure and experimental error are discussed as possible origins of the discrepancies.

AB - Low-carbon martensitic stainless steels with 11.5–16 wt-% Cr and < 0.07 wt-% C are characterised by high corrosion resistance, strength, ductility and impact toughness, obtained by formation of fine-grained reverted austenite from lath martensite upon inter-critical annealing. The review treats the mechanisms governing the formation and stabilisation of reverted austenite and is assisted by the computation of phase equilibria. Literature data on Cr and Ni concentrations of the reverted austenite/martensite dual-phase microstructure are assessed with respect to predicted concentrations. Reasonable agreement was found for concentrations in martensite. Systematic excess of Cr in austenite of approx. 2 wt-% relative to calculations was suspected to originate from the growth of M23C6 with a coherent interface to austenite. Within large scatter, measured values of Ni in austenite were on average 2 wt-% below predictions. Complex equilibration of the microstructure and experimental error are discussed as possible origins of the discrepancies.

KW - Austenite reversion

KW - Microstructure evolution

KW - Solute partitioning

KW - Thermodynamics

KW - CALPHAD

KW - Diffusion

KW - Martensite formation

KW - Residual stress

U2 - 10.1080/02670836.2018.1449179

DO - 10.1080/02670836.2018.1449179

M3 - Journal article

VL - 34

SP - 1401

EP - 1414

JO - Materials Science and Technology

JF - Materials Science and Technology

SN - 0267-0836

IS - 12

ER -