Precipitation and Phase Transformations in 2101 Lean Duplex Stainless Steel During Isothermal Aging

Maetz, J.; Cazottes, Sophie; Verdu, Catherine; Kléber, Xavier

doi:10.1007/s11661-015-3215-7

Cited by 40 publications

(24 citation statements)

References 37 publications

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“…In the case of duplex stainless steels, during isothermal heating, at temperatures below 600 • C, few phase transformation mechanisms can occur [16][17][18][19], with the most important one being spinodal decomposition of the δ-phase into coherent α-phase (Fe-enriched) and α'-phase (Cr-enriched), leading to the following important changes in alloy's exhibited mechanical properties: a high decrease of toughness, an increase in hardness, a small decrease in elongation to fracture, and little or no changes in ultimate tensile strength and yield strength [38]. Other important transformation mechanisms that can occur are represented by the precipitation of secondary phases, such as the R-phase, G-phase, and chromium nitrides [12][13][14][15].…”

Section: Discussionmentioning

confidence: 99%

Influence of Aging Treatment on Microstructure and Tensile Properties of a Hot Deformed UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy

Cojocaru

Răducanu

Nocivin

et al. 2020

Metals

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In this present study, the influence of isothermal aging temperature and duration on microstructural and mechanical properties of a hot-deformed UNS S32750 super duplex stainless steel (SDSS) alloy was investigated by SEM-EBSD (scanning electron microscopy-electron backscatter diffraction) and tensile testing techniques. An isothermal aging treatment, at temperatures between 400 and 600 °C and treatment duration between 3 and 120 h, was applied to a commercial UNS S32750 SDSS alloy. Microstructural characteristics of all thermomechanical (TM) processed states, such as distribution and morphology of constituent phases, grain’s modal orientation (MO), and obtained mechanical properties were analysed correlated with the TM processing conditions. The obtained experimental results show that the constituent phases, in all TM processed states, are represented by elongated γ-phase grains within the δ-phase matrix. The R-phase was observed in the case of aging treatment performed at 600 °C for 120 h. Within the δ-phase matrix, dynamically recrystallized grains were identified as a result of applying hot deformation and isothermal aging treatments. Also, it was observed that aging treatment parameters can significantly influence the mechanical behaviour exhibited by the UNS S32750 SDSS alloy, in terms of elongation to fracture and absorbed energy during impact testing.

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Section: Discussionmentioning

confidence: 99%

Influence of Aging Treatment on Microstructure and Tensile Properties of a Hot Deformed UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy

Cojocaru

Răducanu

Nocivin

et al. 2020

Metals

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“…It has been shown that the high alloying content in these steels increases the risk of precipitation of intermetallic phases, with a negative effect on the corrosion resistance and ductility [5][6][7]. For example, it was reported that precipitation of sigma phase determines the formation of Cr-depleted determines the formation of Cr-depleted zones [12,13], leading to a decrease of mechanical and corrosion resistance and finally to premature failure [14][15][16][17][18][19][20]. The microstructural evolution of SDSS after hot deformation and subsequent solution annealing is very important for preventing the formation of deleterious intermetallic phases and, therefore, the easiest solution to achieve the desired properties seems to be a proper control of thermo-mechanical treatment [21][22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Influence of Solution Treatment Temperature on Microstructural Properties of an Industrially Forged UNS S32750/1.4410/F53 Super Duplex Stainless Steel (SDSS) Alloy

Cojocaru

Şerban

Angelescu

et al. 2017

Metals

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Abstract:In this present study, the influence of solution annealing temperature on microstructural properties of a forged Super Duplex Stainless Steel (SDSS) was investigated by SEM-BSE (Scanning Electron Microscopy-Backscattered Electrons) and SEM-EBSD (Scanning Electron Microscopy-Electron Backscatter Diffraction) techniques. A brief solution treatment was applied to the forged super duplex alloy, at different temperatures between 800 • C and 1100 • C, with a constant holding time of 0.6 ks (10 min). Microstructural characteristics such as nature, weight fraction, distribution and morphology of constituent phases, average grain-size and grain misorientation were analysed in relation to the solution annealing temperature. Experimental results have shown that the constituent phases in the SDSS alloy are δ-Fe, γ-Fe and σ (Cr-Fe) and that their properties are influenced by the solution treatment temperature. SEM examinations revealed microstructural modifications induced by the Cr rich precipitates along the δ/γ and δ/δ grain boundaries, which may significantly affect the toughness and the corrosion resistance of the alloy. Solution annealing at 1100 • C led to complete dissolution of σ (Cr-Fe) phase, the microstructure being formed of primary δ-Fe and γ-Fe. The orientation relationship between δ/δ, γ/γ and δ/γ grains was determined by electron back scattering diffraction (EBSD). Both primary constituent phase's microhardness and global microhardness were determined.

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“…9 The mechanisms of precipitation and phase transformation can be described as follows. 10,11 Both carbides and nitrides precipitate on the g/d phase boundary and cause cracking (embrittlement) during hot deformation. 9 The M 23 C 6 exhibits a specific triangular morphology, while the Cr 2 N exhibits a rod-like morphology.…”

Section: Introductionmentioning

confidence: 99%

“…It is accepted that the embrittlement nose of LDX is approximately from 650°C to 750°C, because of the Cr 2 N and M 23 C 6 precipitation at the g/d and d/d interfaces after a few minutes of aging. 6,[10][11][12] The precipitation of nitrides and carbides was studied in the temperature range where hot rolling usually ends for most steels. Precipitates formed at the upper temperatures in the embrittlement nose (700-900°C for 30 min and 120 min) were studied by qualitative phase analysis.…”

Section: Introductionmentioning

confidence: 99%

Nitrides and carbides in 2101 lean duplex stainless steel

Tehovnik¹,

Batič²,

Vode³

et al. 2018

Mater. Tehnol.

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The 2101 lean duplex stainless steel (LDX) was designed mainly for lightweight constructions and as a more economical substitute for the dominating stainless-steel grades. Compared with other duplex stainless steels, the corrosion resistance and costs of processing the 2101 duplex stainless steel are usually worse, as the Ni and Mo contents are lower; it is compensated by higher N and Mn contents to stabilize the austenite. At lower test temperatures the precipitation of different phases was observed, so different annealing experiments were conducted to further investigate the occurrence of precipitation. As the composition of lean duplex stainless steel differs from that of conventional duplex stainless steels, a different aging behaviour is expected. The embrittlement of 2101 lean duplex stainless steel occurs at approximately 700°C to 750°C, because of the precipitation of the deleterious Cr2N and M23C6 at the d/g and d/ d interfaces, which begins after a few minutes of aging. These temperatures of the nitride precipitations are crucial to the cracking during the end of hot-working operations, which should stop at higher temperatures. The purpose of the research was to qualitatively analyse the phases in lean duplex stainless steel after thermal aging. Optical microscopy (OM), scanning electron microscopy (SEM) and electron-backscatter diffraction (EBSD) were used to investigate the structural stability and the chemical compositions of the phases.

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Precipitation and Phase Transformations in 2101 Lean Duplex Stainless Steel During Isothermal Aging

Cited by 40 publications

References 37 publications

Influence of Aging Treatment on Microstructure and Tensile Properties of a Hot Deformed UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy

Influence of Aging Treatment on Microstructure and Tensile Properties of a Hot Deformed UNS S32750 Super Duplex Stainless Steel (SDSS) Alloy

Influence of Solution Treatment Temperature on Microstructural Properties of an Industrially Forged UNS S32750/1.4410/F53 Super Duplex Stainless Steel (SDSS) Alloy

Nitrides and carbides in 2101 lean duplex stainless steel

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