On the Precipitation of Sigma and Chi Phases in a Cast Super Duplex Stainless Steel

Sousa, R. O.; Lacerda, Pedro; Ferreira, Paulo J.; Ribeiro, Laura M. M.

doi:10.1007/s11661-019-05396-6

Cited by 21 publications

(6 citation statements)

References 35 publications

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“…We note that an increase in PREN in these steels was obtained, first of all, due to nitrogen content growth; therefore, the temperature at which the formation of Cr 2 N starts rose almost to the limit value specified by condition (7). Therefore, for such steels, the "technological gate" of heating temperatures for rolling and the actual rolling process itself has significantly narrowed, with all the associated risks of defects.…”

Section: Steel Composition Optimizationmentioning

confidence: 80%

“…It is known that the precipitate of unfavorable Cr 2 N can occur only with prolonged isothermal exposure when the billet is heated for rolling [30][31][32]. This was taken into account by introducing condition (7), according to which the temperature 2 Cr N 0 T should be lower by ΔT 2 than the temperature of austenite and ferrite existence in equal fractions, which determines the temperature of pre-rolling heating according to condition (5).…”

Section: Steel Composition Optimizationmentioning

confidence: 99%

“…To obtain the duplex structure of steel containing nearly equal fractions of austenite and ferrite, a balance of stabilizers of these phase components is necessary; therefore, with other things being equal, the content of nickel in DSS is lower than in conventional corrosion resistant austenitic stainless steels. Higher level of alloying of advanced DSS leads to the precipitations of undesirable secondary phases, in particular the σ-phase [7] and chromium nitrides [8]. Other secondary phases such as chromium carbides [9] and/or carbonitrides of microalloying elements [10] can also affect the properties of these steels, but the negative effect of the σ-phase and chromium nitrides is predominant [7][8].…”

Section: Introductionmentioning

confidence: 99%

“…Higher level of alloying of advanced DSS leads to the precipitations of undesirable secondary phases, in particular the σ-phase [7] and chromium nitrides [8]. Other secondary phases such as chromium carbides [9] and/or carbonitrides of microalloying elements [10] can also affect the properties of these steels, but the negative effect of the σ-phase and chromium nitrides is predominant [7][8].…”

Section: Introductionmentioning

confidence: 99%

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Development of duplex stainless steels compositions

Zhitenev¹,

Fedorov²,

Kazakov³

et al. 2019

cisisr

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Thermodynamic criteria have been developed for a reasonable prediction of compositions of advanced duplex stainless steels. The success of these criteria was studied under the influence of the primary and secondary alloying elements for duplex stainless steels, and the results of these studies have been generalized using multiple regression equations. It has been revealed that the chemical composition optimization of well-known commercial DSS grades, as well as the development of new grades with specified properties can significantly benefit from the use of these equations. Hot physical experiments have shown that thermodynamic modeling well describes the ferrite content found in experimental steels of different compositions at different quenching temperatures.

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Section: Steel Composition Optimizationmentioning

confidence: 80%

Section: Steel Composition Optimizationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Development of duplex stainless steels compositions

Zhitenev¹,

Fedorov²,

Kazakov³

et al. 2019

cisisr

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“…The precipitation behavior, influencing factors, and effects of the sigma phase on DSS have been widely studied. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Kazuhiro reported the effects of alloying elements on the precipitation of the sigma phase in SDSS. [26,27] The authors found that Cr and Mo, which are useful for improving the corrosion resistance, can promote sigma-phase precipitation, but the phase does not always grow rapidly.…”

mentioning

confidence: 99%

Sigma‐Phase Distribution in 2507 Super Duplex Stainless Steel Continuous Casting Slabs

Chen,

Qiao,

Cheng

et al. 2023

steel research int.

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The sigma‐phase distribution in a 2507 super duplex stainless steel continuous casting slab is analyzed using microstructural analyses and thermodynamic calculations. The sigma phase contains high Cr and Mo contents, and precipitates along the phase boundary between austenite and ferrite and grows toward the interior of the ferrite phase in the continuously cast slab. The sigma‐phase fraction at the center of the width direction is higher than that in the one fourth width. Furthermore, the sigma‐phase fraction at the center of the thickness direction is higher than those at the upper and lower surfaces, which is due to the lower cooling rate at the center. The Brinell hardness (HB) at the center increases to 313 HB with an increasing sigma‐phase fraction. The sigma‐phase fraction at the one fourth thickness near the lower surface is higher than that at the one fourth thickness near the upper surface at the same cooling rate. Additionally, Mo and Ni are severely segregated in this zone. A higher Mo content influences the precipitation and stabilization of the sigma phase. Furthermore, Scheil–Gulliver calculations indicate that compositional segregation results in an increase in the sigma‐phase precipitation temperature range.

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