475 °C embrittlement

Electron backscatter diffraction map of 128 hrs age hardened duplex stainless steel with the ferrite phase forming the matrix and austenite grains sporadically spread. The ferrite phase volume fraction is 58%. ^[1]

EBSD map with austenite grains excluded (white). The scale bar is 500 µm. Colours denote the crystal orientation and are taken from the inverse pole figure at the lower right corner. ^[2]

Duplex stainless steels are a family of alloys with a two-phase microstructure consisting of both austenitic (face-centred cubic) and ferritic (body-centred cubic) phases. They offer excellent mechanical properties, corrosion resistance, and toughness compared to other types of stainless steel. However, duplex stainless steel can be susceptible to a phenomenon known as 475 °C embrittlement or duplex stainless steel age hardening, which is a type of aging process that causes loss of plasticity in duplex stainless steel when it is heated in the range of 250 to 550 °C (480 to 1,020 °F). At this temperature range, spontaneous phase separation of the ferrite phase into iron-rich and chromium-rich nanophases occurs, with no change in the mechanical properties of the austenite phase. This type of embrittlement is due to precipitation hardening, which makes the material become brittle and prone to cracking.

Duplex stainless steel

See also: Duplex stainless steel

Duplex stainless steel is a type of stainless steel that has a two-phase microstructure consisting of both austenitic (face-centred cubic) and ferritic (body-centred cubic) phases. ^{[3] [4]} This dual-phase structure gives duplex stainless steel a combination of mechanical and corrosion-resistant properties that are superior to those of either austenitic or ferritic stainless steel alone. ^{[3] [4]} The austenitic phase provides the steel with good ductility, high toughness, and high corrosion resistance, especially in acidic and chloride-containing environments. ^{[3] [4]} The ferritic phase, on the other hand, provides the steel with good strength, high resistance to stress corrosion cracking, and high resistance to pitting and crevice corrosion. ^{[3] [4]} They are therefore used extensively in the offshore oil and gas industry for pipework systems, manifolds, risers, etc. and in the petrochemical industry in the form of pipelines and pressure vessels. ^[3]

A duplex stainless steel mixture of austenite and ferrite microstructure is not necessarily in equal proportions, and where the alloy solidifies as ferrite, it is partially transformed to austenite when the temperature falls to around 1,000 °C (1,830 °F). ^{[5] [6]} Duplex steels have a higher chromium content compared to austenitic stainless steel, 20–28%; higher molybdenum, up to 5%; lower nickel, up to 9%; and 0.05–0.50% nitrogen. ^{[6] [5]} Thus, duplex stainless steel alloys have good corrosion resistance and higher strength than standard austenitic stainless steels such as type 304 or 316. ^{[7] [4]}

Alpha (α) phase is a ferritic phase with body-centred cubic (BCC) structure, Im${\displaystyle {\bar {3}}}$m [229] space group, 2.866 Å lattice parameter, and has one twinning system {112}<111> and three slip systems {110}<111>, {112}<111> and {123}<111>; however, the last system rarely activates. ^{[8] [9]} Gamma (${\displaystyle \gamma }$) phase is austenitic with a face-centred cubic (FCC) structure, Fm${\displaystyle {\bar {3}}}$m [259] space group, and 3.66 Å lattice parameter. It normally has more nickel, copper, and interstitial carbon and nitrogen. ^[10] Plastic deformation occurs in austenite more readily than in ferrite. ^{[11] [2]} During deformation, straight slip bands form in the austenite grains and propagate to the ferrite-austenite grain boundaries, assisting in the slipping of the ferrite phase. Curved slip bands also form due to the bulk-ferrite-grain deformation. ^{[12] [13] [14]} The formation of slip bands indicates a concentrated unidirectional slip on certain planes causing a stress concentration. ^[15]

Age hardening by spinodal decomposition

See also: Spinodal decomposition

Calculated metastable miscibility gap in the Fe-Cr binary system (remake of )

Duplex stainless steel can have limited toughness due to its large ferritic grain size, and its tendencies to hardening and embrittlement, i.e., loss of plasticity, at temperatures ranging from 250 to 550 °C (482 to 1,022 °F), especially at 475 °C (887 °F). ^[18] At this temperature range, spinodal decomposition of the supersaturated solid ferrite solution into iron-rich nanophase (${\displaystyle {\acute {a}}}$) and chromium-rich nanophase (${\displaystyle {\acute {a}}{\acute {}}}$), accompanied by G-phase precipitation, occurs. ^{[18] [19] [20]} This makes the ferrite phase a preferential initiation site for micro-cracks. ^[21] This is because aging encourages Σ3 {112}<111> ferrite deformation twinning at slow strain rate and room temperature in tensile or compressive deformation, nucleating from local stress concentration sites, ^{[18] [22]} and parent-twinning boundaries, with 60° (in or out) misorientation, are suitable for cleavage crack nucleation. ^{[22] [23] [24]}

Spinodal decomposition refers to the spontaneous separation of a phase into two coherent phases via uphill diffusion, i.e., from a region of lower concentration to a region of higher concentration resulting in a negative diffusion coefficient ${\displaystyle {d^{2}G \over dx^{2}}}$, without a barrier to nucleation due to the phase being thermodynamically unstable (i.e., miscibility gap, ${\displaystyle {\acute {a}}}$ + ${\displaystyle {\acute {a}}{\acute {}}}$ region in the figure), ^[25] where ${\displaystyle G}$ is the Gibbs free energy per mole of solution and the composition. It increases hardness and decreases magneticity. ^[26] Miscibility gap describes the region in a phase diagram below the melting point of each compound where the solid phase splits into the liquid of two separated stable phases. ^[27]

For 475 °C embrittlement to occur, the chromium content needs to exceed 12%. ^[28] The addition of nickel accelerates the spinodal decomposition by promoting the iron-rich nanophase formation. ^[29] Nitrogen changes the distribution of chromium, nickel, and molybdenum in the ferrite phase but does not prevent the phase decomposition. ^[30] Other elements like molybdenum, manganese, and silicon do not affect the formation of iron-rich nanophase. ^[31] However, manganese and molybdenum partition to the iron-rich nanophase, while nickel partitions to the chromium-rich nanophase. ^[19]

Microscopy characterisation

Microstructural evolution under the Cahn–Hilliard equation, demonstrating distinctive coarsening and phase separation

Using Field Emission Gun Transmission Electron Microscope FEG-TEM, the nanometre-scaled modulated structure of the decomposed ferrite was revealed as chromium-rich nanophase gave the bright image, and iron-rich darker image. ^[19] It also revealed that these modulated nanophases grow coarser with aging time. ^{[19] [32]} Decomposed phases start as irregular rounded shapes with no particular arrangement, but with time the chromium-rich nanophase takes a plat shape aligned in the <110> directions. ^[32]

Consequences

Change of hardness (measured using diamond Vicker indenter and expressed in Vickers Pyramid Number, HV) with 2, 4, 8, 16, 32, 64, and 128 hours aging time for the ferrite phase in super-duplex Zeron 100 alloy. The indent was done in 11 widely separated locations in each aged sample.

Spinodal decomposition increases the hardening of the material due to the misfit between the chromium-rich and iron-rich nano-phases, internal stress, and variation of elastic modulus. The formation of coherent precipitates induces an equal but opposite strain, raising the system's free energy depending on the precipitate shape and matrix and precipitate elastic properties. ^{[27] [33]} Around a spherical inclusion, the distortion is purely hydrostatic. ^[27]

G-phase precipitates appear prominently at grain boundaries. ^[20] and are phase rich in nickel, titanium, and silicon, ^[20] but chromium and manganese may substitute titanium sites. ^[34] G-phase precipitates occur during long-term aging, are encouraged by increasing nickel content in the ferrite phase, ^[34] and reduce corrosion resistance significantly. ^[35] It has ellipsoid morphology, FCC structure (Fm${\displaystyle {\bar {3}}}$m), and 11.4 Å lattice parameter, ^[36] with a diameter less than 50 nm that increases with aging. ^{[37] [38]}

Thus, the embrittlement is caused by dislocations impediment/ locking by the spinodally decomposed matrix ^{[39] [40]} and strain around G-phase precipitates, ^[41] i.e., internal stress relaxation by the formation of Cottrell atmosphere. ^[42]

Furthermore, the ferrite hardness increases with aging time, the hardness of the ductile austenite phase remains nearly unchanged ^{[39] [40] [43]} due to faster diffusivity in ferrite compared to the austenite. ^[26] However, austenite undergoes a substitutional redistribution of elements, enhancing galvanic corrosion between the two phases. ^[44]

Treatment

550 °C heat treatment can reverse spinodal decomposition but not affect the G-phase precipitates. ^[45] The ferrite matrix spinodal decomposition can be substantially reversed by introducing an external pulsed electric current that changes the system's free energy due to the difference in electrical conductivity between the nanophases and the dissolution of G-phase precipitates. ^{[46] [47]}

Cyclic loading suppresses spinodal decomposition, ^[48] and radiation accelerates it but changes the decomposition nature from an interconnected network of modulated nanophases to isolated islands. ^[49]

References

1. Mohamed Koko, A. (2022). In situ full-field characterisation of strain concentrations (deformation twins, slip bands and cracks) (PhD Thesis thesis). University of Oxford. Archived from the original on 1 February 2023. Retrieved 2 March 2023.  This article incorporates textfrom this source, which is available under the CC BY 4.0 license.
2. Koko, Abdalrhaman; Elmukashfi, Elsiddig; Becker, Thorsten H.; Karamched, Phani S.; Wilkinson, Angus J.; Marrow, T. James (15 October 2022). "In situ characterisation of the strain fields of intragranular slip bands in ferrite by high-resolution electron backscatter diffraction". Acta Materialia. 239: 118284. Bibcode:2022AcMat.23918284K. doi: 10.1016/j.actamat.2022.118284 . ISSN   1359-6454. S2CID   251783802.
3. International Stainless Steel Forum (2020). "Duplex Stainless Steels" (PDF). Archived (PDF) from the original on 5 March 2023. Retrieved 25 March 2023.
4. Peckner, Donald; Bernstein, I.M. (1977). "chapter 8". Handbook of Stainless Steels. McGraw Hill. ISBN   9780070491472.
5. Charles, Jacques (2010). Proceedings of the Duplex Stainless Steel Conference, Beaune (2010). EDP Sciences, Paris. pp. 29–82. Archived from the original on 6 May 2022. Retrieved 25 March 2023.
6. Practical Guidelines for the Fabrication of Duplex Stainless Steels (PDF) (3rd ed.). International Molybdenum Association (IMOA). 2014. ISBN   978-1-907470-09-7. Archived (PDF) from the original on 10 March 2023. Retrieved 25 March 2023.
7. Alvarez-Armas, Iris (2008). "Duplex Stainless Steels: Brief History and Some Recent Alloys". Recent Patents on Mechanical Engineering. 1 (1): 51–57. doi:10.2174/2212797610801010051. Archived from the original on 14 October 2022. Retrieved 14 October 2022.
8. Du, C.; Maresca, F.; Geers, M. G. D.; Hoefnagels, J. P. M. (1 March 2018). "Ferrite slip system activation investigated by uniaxial micro-tensile tests and simulations". Acta Materialia. 146: 314–327. Bibcode:2018AcMat.146..314D. doi:10.1016/j.actamat.2017.12.054. ISSN   1359-6454.
9. Koko, Abdalrhaman; Elmukashfi, Elsiddig; Dragnevski, Kalin; Wilkinson, Angus J.; Marrow, Thomas James (1 October 2021). "J-integral analysis of the elastic strain fields of ferrite deformation twins using electron backscatter diffraction". Acta Materialia. 218: 117203. Bibcode:2021AcMat.21817203K. doi:10.1016/j.actamat.2021.117203. ISSN   1359-6454.
10. Nilsson, J.-O. (1 August 1992). "Super duplex stainless steels". Materials Science and Technology. 8 (8): 685–700. Bibcode:1992MatST...8..685N. doi:10.1179/mst.1992.8.8.685. ISSN   0267-0836. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
11. Zieliński, W.; Świątnicki, W.; Barstch, M.; Messerschmidt, U. (28 August 2003). "Non-uniform distribution of plastic strain in duplex steel during TEM in situ deformation". Materials Chemistry and Physics. 81 (2): 476–479. doi:10.1016/S0254-0584(03)00059-2. ISSN   0254-0584.
12. Serre, I.; Salazar, D.; Vogt, J.-B. (September 2008). "Atomic force microscopy investigation of surface relief in individual phases of deformed duplex stainless steel". Materials Science and Engineering: A. 492 (1–2): 428–433. doi:10.1016/j.msea.2008.04.060. Archived from the original on 11 August 2022. Retrieved 14 October 2022.
13. Li Z, Hu Y, Chen T, Wang X, Liu P, Lu Y (December 2020). "Microstructural Evolution and Mechanical Behavior of Thermally Aged Cast Duplex Stainless Steel". Materials. 13 (24): 5636. Bibcode:2020Mate...13.5636L. doi: 10.3390/ma13245636 . PMC   7763132 . PMID   33321825.
14. Zhang, Qingdong; Ma, Sida; Jing, Tao (March 2019). "Mechanical Properties of a Thermally-aged Cast Duplex Stainless Steel by in Situ Tensile Test at the Service Temperature". Metals. 9 (3): 317. doi: 10.3390/met9030317 . ISSN   2075-4701.
15. Sangid, Michael D. (1 December 2013). "The physics of fatigue crack initiation". International Journal of Fatigue. Fatigue and Microstructure: A special issue on recent advances. 57: 58–72. doi:10.1016/j.ijfatigue.2012.10.009. ISSN   0142-1123.
16. Fan, Y.; Liu, T.G.; Xin, L.; Han, Y.M.; Lu, Y.H.; Shoji, T. (February 2021). "Thermal aging behaviors of duplex stainless steels used in nuclear power plant: A review". Journal of Nuclear Materials. 544: 152693. Bibcode:2021JNuM..54452693F. doi:10.1016/j.jnucmat.2020.152693. S2CID   229461947. Archived from the original on 23 October 2022. Retrieved 14 October 2022.
17. Bonny, G.; Terentyev, D.; Malerba, L. (October 2010). "New Contribution to the Thermodynamics of Fe-Cr Alloys as Base for Ferritic Steels". Journal of Phase Equilibria and Diffusion. 31 (5): 439–444. doi:10.1007/s11669-010-9782-9. ISSN   1547-7037. S2CID   95044045. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
18. Örnek, Cem; Burke, M. G.; Hashimoto, T.; Engelberg, D. L. (April 2017). "748 K (475 °C) Embrittlement of Duplex Stainless Steel: Effect on Microstructure and Fracture Behavior". Metallurgical and Materials Transactions A. 48 (4): 1653–1665. Bibcode:2017MMTA...48.1653O. doi: 10.1007/s11661-016-3944-2 . ISSN   1073-5623. S2CID   136321604.
19. Weng, K. L; Chen, H. R; Yang, J. R (15 August 2004). "The low-temperature aging embrittlement in a 2205 duplex stainless steel". Materials Science and Engineering: A. 379 (1): 119–132. doi:10.1016/j.msea.2003.12.051. ISSN   0921-5093.
20. Beattie, H. J.; Versnyder, F. L. (July 1956). "A New Complex Phase in a High-Temperature Alloy". Nature. 178 (4526): 208–209. Bibcode:1956Natur.178..208B. doi:10.1038/178208b0. ISSN   1476-4687. S2CID   4217639. Archived from the original on 14 October 2022. Retrieved 14 October 2022.
21. Liu, Gang; Li, Shi-Lei; Zhang, Hai-Long; Wang, Xi-Tao; Wang, Yan-Li (August 2018). "Characterization of Impact Deformation Behavior of a Thermally Aged Duplex Stainless Steel by EBSD". Acta Metallurgica Sinica (English Letters). 31 (8): 798–806. doi: 10.1007/s40195-018-0708-6 . ISSN   1006-7191. S2CID   139395583.
22. Marrow, T. J.; Humphreys, A. O.; Strangwood, M. (July 1997). "The Crack Initiation Toughness for Brittle Fracture of Super Duplex Stainless Steel". Fatigue & Fracture of Engineering Materials & Structures. 20 (7): 1005–1014. doi:10.1111/j.1460-2695.1997.tb01543.x. Archived from the original on 14 October 2022. Retrieved 14 October 2022.
23. Kato, Masaharu (January 1981). "Hardening by spinodally modulated structure in b.c.c. alloys". Acta Metallurgica. 29 (1): 79–87. doi:10.1016/0001-6160(81)90088-2. Archived from the original on 3 July 2018. Retrieved 14 October 2022.
24. Marrow, T. J.; Harris, C. (July 1996). "The Fracture Mechanism of 475°C Embrittlement in a Duplex Stainless Steel". Fatigue & Fracture of Engineering Materials & Structures. 19 (7): 935–947. doi:10.1111/j.1460-2695.1996.tb01028.x. Archived from the original on 14 October 2022. Retrieved 14 October 2022.
25. Mburu, Sarah; Kolli, R. Prakash; Perea, Daniel E.; Schwarm, Samuel C.; Eaton, Arielle; Liu, Jia; Patel, Shiv; Bartrand, Jonah; Ankem, Sreeramamurthy (April 2017). "Effect of aging temperature on phase decomposition and mechanical properties in cast duplex stainless steels". Materials Science and Engineering: A. 690: 365–377. doi: 10.1016/j.msea.2017.03.011 .
26. Örnek, C.; Burke, M. G.; Hashimoto, T.; Lim, J. J. H.; Engelberg, D. L. (26 May 2017). "475°C Embrittlement of Duplex Stainless Steel—A Comprehensive Microstructure Characterization Study". Materials Performance and Characterization. 6 (3): MPC20160088. doi:10.1520/MPC20160088. Archived from the original on 3 June 2018. Retrieved 14 October 2022.
27. Porter, David A.; Easterling, Kenneth E.; Sherif, Mohamed Y. (2021). Phase Transformations in Metals and Alloys. [S.l.]: CRC Press. ISBN   978-1-000-46779-6. OCLC   1267751972.
28. Sahu, J. K.; Krupp, U.; Ghosh, R. N.; Christ, H. -J. (20 May 2009). "Effect of 475°C embrittlement on the mechanical properties of duplex stainless steel". Materials Science and Engineering: A. 508 (1): 1–14. doi:10.1016/j.msea.2009.01.039. ISSN   0921-5093.
29. Miller, M. K.; Russell, K. F. (2 March 1996). "Comparison of the rate of decomposition in Fe45%Cr, Fe45%Cr5%Ni and duplex stainless steels". Applied Surface Science. Proceedings of the 42nd International Field Emission Symposium. 94–95: 398–402. Bibcode:1996ApSS...94..398M. doi:10.1016/0169-4332(95)00403-3. ISSN   0169-4332.
30. Bliznuk, T.; Mola, M.; Polshin, E.; Pohl, M.; Gavriljuk, V. (25 September 2005). "Effect of nitrogen on short-range atomic order in the feritic δ phase of a duplex steel". Materials Science and Engineering: A. 405 (1): 11–17. doi:10.1016/j.msea.2005.05.094. ISSN   0921-5093.
31. Solomon, H. D.; Levinson, Lionel M. (1 March 1978). "Mössbauer effect study of '475°c embrittlement' of duplex and ferritic stainless steels". Acta Metallurgica. 26 (3): 429–442. doi:10.1016/0001-6160(78)90169-4. ISSN   0001-6160.
32. Soriano-Vargas, Orlando; Avila-Davila, Erika O.; Lopez-Hirata, Victor M.; Cayetano-Castro, Nicolas; Gonzalez-Velazquez, Jorge L. (May 2010). "Effect of spinodal decomposition on the mechanical behavior of Fe–Cr alloys". Materials Science and Engineering: A. 527 (12): 2910–2914. doi:10.1016/j.msea.2010.01.020. Archived from the original on 3 August 2022. Retrieved 14 October 2022.
33. Cahn, John W (1 September 1961). "On spinodal decomposition". Acta Metallurgica. 9 (9): 795–801. doi:10.1016/0001-6160(61)90182-1. ISSN   0001-6160. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
34. Sakata, Mikihiro; Kadoi, Kota; Inoue, Hiroshige (December 2021). "Acceleration of 475 °C embrittlement in weld metal of 22 mass% Cr-duplex stainless steel". Materials Today Communications. 29: 102800. doi: 10.1016/j.mtcomm.2021.102800 . S2CID   240575697.
35. Xue, Fei; Shi, Fangjie; Zhang, Chuangju; Zheng, Qiaoling; Yi, Dawei; Li, Xiuqing; Li, Yefei (21 July 2021). "The Microstructure and Mechanical and Corrosion Behaviors of Thermally Aged Z3CN20-09M Cast Stainless Steel for Primary Coolant Pipes of Nuclear Power Plants". Coatings. 11 (8): 870. doi: 10.3390/coatings11080870 . ISSN   2079-6412.
36. Li, Shilei; Wang, Yanli; Wang, Xitao; Xue, Fei (September 2014). "G-phase precipitation in duplex stainless steels after long-term thermal aging: A high-resolution transmission electron microscopy study". Journal of Nuclear Materials. 452 (1–3): 382–388. Bibcode:2014JNuM..452..382L. doi:10.1016/j.jnucmat.2014.05.069. Archived from the original on 23 October 2022. Retrieved 14 October 2022.
37. Hamaoka, T.; Nomoto, A.; Nishida, K.; Dohi, K.; Soneda, N. (December 2012). "Effects of aging temperature on G-phase precipitation and ferrite-phase decomposition in duplex stainless steel". Philosophical Magazine. 92 (34): 4354–4375. Bibcode:2012PMag...92.4354H. doi:10.1080/14786435.2012.707340. ISSN   1478-6435. S2CID   135586095. Archived from the original on 15 June 2022. Retrieved 14 October 2022.
38. Mateo, A; Llanes, L; Anglada, M; Redjaimia, A; Metauer, G (1997). "Characterization of the intermetallic G-phase in an AISI 329 duplex stainless steel". Journal of Materials Science. 32 (17): 4533–4540. doi:10.1023/A:1018669217124. S2CID   134334541. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
39. Zhang, Qingdong; Singaravelu, Arun Sundar S.; Zhao, Yongfeng; Jing, Tao; Chawla, Nikhilesh (16 January 2019). "Mechanical properties of a thermally-aged cast duplex stainless steel by nanoindentation and micropillar compression". Materials Science and Engineering: A. 743: 520–528. doi:10.1016/j.msea.2018.11.112. ISSN   0921-5093. S2CID   139168335.
40. Lee, Ho Jung; Kong, Byeong Seo; Obulan Subramanian, Gokul; Heo, Jaewon; Jang, Changheui; Lee, Kyoung-Soo (1 October 2018). "Evaluation of thermal aging of δ-ferrite in austenitic stainless steel weld using nanopillar compression test". Scripta Materialia. 155: 32–36. doi:10.1016/j.scriptamat.2018.06.016. ISSN   1359-6462. S2CID   139130674.
41. Badyka, R.; Monnet, G.; Saillet, S.; Domain, C.; Pareige, C. (February 2019). "Quantification of hardening contribution of G-Phase precipitation and spinodal decomposition in aged duplex stainless steel: APT analysis and micro-hardness measurements". Journal of Nuclear Materials. 514: 266–275. Bibcode:2019JNuM..514..266B. doi:10.1016/j.jnucmat.2018.12.002. S2CID   105302671. Archived from the original on 23 October 2022. Retrieved 14 October 2022.
42. Calcagnotto, Marion; Adachi, Yoshitaka; Ponge, Dirk; Raabe, Dierk (January 2011). "Deformation and fracture mechanisms in fine- and ultrafine-grained ferrite/martensite dual-phase steels and the effect of aging". Acta Materialia. 59 (2): 658–670. Bibcode:2011AcMat..59..658C. doi:10.1016/j.actamat.2010.10.002. Archived from the original on 20 June 2022. Retrieved 14 October 2022.
43. Godfrey, T. J.; Smith, G. D.W. (November 1986). "The Atom Probe Analysis of a Cast Duplex Stainless Steel". Le Journal de Physique Colloques. 47 (C7): C7–217–C7-222. doi:10.1051/jphyscol:1986738. ISSN   0449-1947. S2CID   93304045. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
44. May, J.E.; de Sousa, C.A.C.; Kuri, S.E. (July 2003). "Aspects of the anodic behaviour of duplex stainless steels aged for long periods at low temperatures". Corrosion Science. 45 (7): 1395–1403. doi:10.1016/S0010-938X(02)00244-5. S2CID   96597890. Archived from the original on 2 July 2018. Retrieved 14 October 2022.
45. Lee, Ho Jung; Kong, Byeong Seo; Obulan Subramanian, Gokul; Heo, Jaewon; Jang, Changheui; Lee, Kyoung-Soo (October 2018). "Evaluation of thermal aging of δ-ferrite in austenitic stainless steel weld using nanopillar compression test". Scripta Materialia. 155: 32–36. doi:10.1016/j.scriptamat.2018.06.016. S2CID   139130674. Archived from the original on 23 October 2022. Retrieved 14 October 2022.
46. Liu, Xuebing; Zhang, Xinfang (August 2018). "An ultrafast performance regeneration of aged stainless steel by pulsed electric current". Scripta Materialia. 153: 86–89. doi:10.1016/j.scriptamat.2018.05.004. S2CID   139625954. Archived from the original on 25 March 2023. Retrieved 14 October 2022.
47. Liu, Xuebing; Lu, Wenjun; Zhang, Xinfang (January 2020). "Reconstructing the decomposed ferrite phase to achieve toughness regeneration in a duplex stainless steel". Acta Materialia. 183: 51–63. Bibcode:2020AcMat.183...51L. doi:10.1016/j.actamat.2019.11.008. S2CID   210229887. Archived from the original on 24 October 2022. Retrieved 14 October 2022.
48. Akita, Masayuki; Kakiuchi, Toshifumi; Uematsu, Yoshihiko (2011). "Microstructural Changes of High-Chromium Ferritic Stainless Steel Subjected to Cyclic Loading in 475°C Embrittlement Region". Procedia Engineering. 10: 100–105. doi: 10.1016/j.proeng.2011.04.019 .
49. Miller, M.K.; Stoller, R.E.; Russell, K.F. (June 1996). "Effect of neutron-irradiation on the spinodal decomposition of Fe-32% Cr model alloy". Journal of Nuclear Materials. 230 (3): 219–225. Bibcode:1996JNuM..230..219M. doi:10.1016/0022-3115(96)80017-1. Archived from the original on 27 June 2018. Retrieved 14 October 2022.

Further reading

• Sahu, J.K.; Krupp, U.; Ghosh, R.N.; Christ, H.-J. (20 May 2009). "Effect of 475 °C embrittlement on the mechanical properties of duplex stainless steel". Materials Science and Engineering: A. 508 (1–2): 1–14. doi:10.1016/j.msea.2009.01.039.
• Bonny, G; Terentyev, D; Malerba, L (2010). "New Contribution to the Thermodynamics of Fe-Cr Alloys as Base for Ferritic Steels". Journal of Phase Equilibria and Diffusion. 31 (5): 439–444. doi:10.1007/S11669-010-9782-9. S2CID   95044045.