On Microstructure and Microhardness of Isothermally Aged UNS S32760 and the Effect on Toughness and Corrosion Behavior

Elsabbagh, Fady M.; Hamouda, Rawia M.; Taha, M. A.

doi:10.1007/s11665-013-0619-7

Cited by 12 publications

(6 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…However, its main drawback is the tendency to form detrimental phases at temperatures between 600 • C and 900 • C, being the cause of a significant loss of toughness and resistance to localized corrosion. One of the most known and representative detrimental phases is the precipitation of the sigma phase (σ), a Cr-and Mo-rich intermetallic compound [12][13][14][15][16][17][18][19][20][21]. This σ phase shows a tetragonal crystallographic structure with 32 atoms per unit cell [22] making possible a considerable increase in the resultant hardness, whereas a decrease in the toughness as well as elongation is also observed [23][24][25][26][27].…”

Section: Introductionmentioning

confidence: 99%

Effect of the Temperature in the Mechanical Properties of Austenite, Ferrite and Sigma Phases of Duplex Stainless Steels Using Hardness, Microhardness and Nanoindentation Techniques

Argandoña¹,

Palacio

Berlanga

et al. 2017

Metals

View full text Add to dashboard Cite

Abstract:The aim of this work is to study the hardness of the ferrite, austenite and sigma phases of a UNS S32760 superduplex stainless steel submitted to different thermal treatments, thus leading to different percentages of the mentioned phases. A comparative study has been performed in order to evaluate the resulting mechanical properties of these phases by using hardness, microhardness and nanoindentation techniques. In addition, optical microscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD) have been also used to identify their presence and distribution. Finally, the experimental results have shown that the resulting hardness values were increased as a function of a longer heat treatment duration which it is associated to the formation of a higher percentage of the sigma phase. However, nanoindentation hardness measurements of this sigma phase showed lower values than expected, being a combination of two main factors, namely the complexity of the sigma phase structure as well as the surface finish (roughness).

show abstract

Section: Introductionmentioning

confidence: 99%

Effect of the Temperature in the Mechanical Properties of Austenite, Ferrite and Sigma Phases of Duplex Stainless Steels Using Hardness, Microhardness and Nanoindentation Techniques

Argandoña¹,

Palacio

Berlanga

et al. 2017

Metals

View full text Add to dashboard Cite

show abstract

“…It happened due to the growth of austenite grains followed by their union. This process results in massive austenite and consequently in a heterogeneous microstructure [47][48][49] .…”

Section: Resultsmentioning

confidence: 99%

“…The assays of corrosion by DL-EPR were performed in a solution composed of 1 M H 2 SO 4 + 0.5 M NaCl + 0.01 M KSCN at 25°C. This choice was based on the study of Zhao et al 43 , that successfully assessed the intergranular corrosion of LDX 2404 DSS 2404 aged at 700 o C. The curves by DL-EPR were obtained by the scan of the potential from -0.5 to 0.2V, and the scan was reversed and scanned from positive to negative potentials until -0.5V at a constant rate of 1.67mV/s 36,[44][45][46][47][48] .…”

Section: Methodsmentioning

confidence: 99%

Effect of Precipitation of Alpha Line and Sigma Phases on the Microstructure and Corrosion Resistance of the Duplex Stainless Steel SAF 2205

Dainezi¹,

Borges

Mariano

2023

Mat. Res.

View full text Add to dashboard Cite

The purpose of this work was to evaluate the microstructural alterations associated to the aging thermal treatments performed at 450, 475, 800 and 850°C, for 1, 3 and 12h, besides evaluating the influence of the precipitation of the alpha line phase on corrosion resistance. The samples were characterized by scanning electron microscopy, energy dispersion spectrometry, X-ray diffraction, feritscope, hardness, microhardness, in addition cyclic potentiodynamic polarization and double loop electrochemical potentiokinetic reactivation. In the agings performed at 450°C for 1h and 475°C for 12h, there was precipitation of the alpha line phase inside the ferrite and there was no significant effect on the resistance to pitting corrosion and the phenomenon of sensitization was not promoted.In the aging at 800 and 850°C for 1, 3 and 12h, the sigma phase was formed from the consumption of ferrite, and in the aging at 850°C there was the precipitation of the chi phase, promoting the increase in steel hardness. In agings for 12 h at 800 and 850°C, there was resistance to pitting corrosion decrease and the phenomenon of sensitization was moderated promoted at 800°C, with just the sigma phase precipitation and promoted at 850°C with sigma and chi phases precipitation.

show abstract

“…Similarly, the specimens of FSS and SASS constituent' steels, were also isothermally heat treated for the formation of secondary precipitates at the lower and higher temperature ranges as shown in Table 3 and Table 4, respectively. Based on TTT diagrams of the austenitic and ferritic steels [18] [19], a scheme for the isothermal heat treatment conditions applied on the composite and the two constituent's steels is shown in Figure 1.…”

Section: Heat Treatmentmentioning

confidence: 99%

Analysis of Super Duplex Stainless Steel Properties as an Austenite-Ferrite Composite

Elsabbagh

Hamouda

et al. 2015

MSA

Self Cite

View full text Add to dashboard Cite

Super duplex stainless steel (SDSS) is considered as a composite formed from a microstructure of an approximately equal mixture of two primary constituents (γ-austenite and α-ferrite phases) and the secondary precipitates (sigma, chi, alpha-prime, etc.). While the formation of these phases affects the properties of SDSS, however there are no rules that govern the relationship. In this work, the relationship between toughness as well as corrosion behavior of SDSS (UNS 32760) and the microstructure constituents has been experimentally investigated, and analyzed in view of the composite principles. Another two stainless steels namely; fully austenitic SASS (UNS N08367) and fully ferritic FSS (UNS S42900) are considered to simulate the constituent's primary components in the composite which are austenite γ and ferrite α phases respectively. Samples of the composite and constituent's steels are first subjected to solution annealing, where the composite steel has a microstructure of γ austenite and α ferrite grains. They were then subjected to similar different isothermal heat treatment cycles, for the formation of secondary phase precipitations within the transformation temperature ranges of each of γ and α primary grains. Impact toughness and corrosion (specific weight loss) tests were conducted on the annealed and isothermally treated samples. The composite rule of the mixtures (ROM) is used to analyze the relationship between the toughness and corrosion properties in the composite SDSS and the SASS and FSS constituent's steels. The analysis indicates that in case of toughness, ROM applies well on the composite and constituents' steels in the solution annealed and in isothermal treatment conditions, where better matching between experimental and calculated results is observed. When applying ROM for corrosion weight loss, a great difference is found between the experimental and calculated results, which is much reduced for solution treated samples ferritic and austenitic temperature ranges of 480˚C-500˚C and 700˚C-750˚C as for ferrite and austenite respectively.

show abstract

On Microstructure and Microhardness of Isothermally Aged UNS S32760 and the Effect on Toughness and Corrosion Behavior

Cited by 12 publications

References 12 publications

Effect of the Temperature in the Mechanical Properties of Austenite, Ferrite and Sigma Phases of Duplex Stainless Steels Using Hardness, Microhardness and Nanoindentation Techniques

Effect of the Temperature in the Mechanical Properties of Austenite, Ferrite and Sigma Phases of Duplex Stainless Steels Using Hardness, Microhardness and Nanoindentation Techniques

Effect of Precipitation of Alpha Line and Sigma Phases on the Microstructure and Corrosion Resistance of the Duplex Stainless Steel SAF 2205

Analysis of Super Duplex Stainless Steel Properties as an Austenite-Ferrite Composite

Contact Info

Product

Resources

About