Microstructural Characterization of Ferritic/Martensitic Steels by Positron Annihilation Spectroscopy

Babu, S. Hari; Amarendra, G.; Rajaraman, R.; Sundar, C. S.

doi:10.1088/1742-6596/443/1/012010

Cited by 13 publications

(7 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…vacancies associated with dislocations and/or open volume defects at martensite-ferrite interfaces), while the second component (290 ps; 7%) characterizes small vacancy clusters. We do not expect positron trapping at carbide clusters' interfaces [27].The CDBS S-parameter of 0.482 was calculated from the unirradiated sample data.…”

Section: Resultsmentioning

confidence: 99%

Helium behavior in ferritic/martensitic steels irradiated in spallation target

Kršjak

Kuriplach

Shen

et al. 2015

Journal of Nuclear Materials

View full text Add to dashboard Cite

Section: Resultsmentioning

confidence: 99%

Helium behavior in ferritic/martensitic steels irradiated in spallation target

Kršjak

Kuriplach

Shen

et al. 2015

Journal of Nuclear Materials

View full text Add to dashboard Cite

“…Several studies reported the increase of the S-parameter or mean positron lifetime values in ferritic/martensitic steels which could be attributed to the nucleation and growth of metal carbide precipitates mainly M 23 C 6 at temperatures above 500°C. In that case, the positron trapping sites were expected to be precipitate matrix interfaces [42]. The subsequent decrease of these parameters with a minimum at 800°C was explained as caused by coarsening of the precipitates and decrease of positron trapping.…”

Section: Discussionmentioning

confidence: 99%

“…PAS was applied to determine vacancy migration energy in SS [37,38]. Sensitivity of PAS is sufficient for investigation of the phase transformations in different materials [39,40], and this technique has been profitably applied in microstructural characterization of steels which are candidates for structural materials in nuclear facilities [41,42].…”

Section: Introductionmentioning

confidence: 99%

Reverse transformation of deformation-induced martensite in austenitic stainless steel studied by positron annihilation

2014

View full text Add to dashboard Cite

The reversion of deformation-induced a 0 -martensite in tension-deformed 1.4301 (EN) stainless steel was investigated using positron annihilation spectroscopy. The Doppler broadening of the annihilation line and positron lifetime spectroscopy were applied to study defect structure and its annealing behavior in samples with a similar deformation level but varying in a 0 -martensite amount. The difference in a 0 -martensite was obtained by applying different deformation temperatures, i.e., liquid nitrogen temperature, room temperature, and 200°C. The cumulative annealing of the tension-deformed samples and measurement of the positron annihilation characteristics show the gradual annealing of defects in the temperature range between 200 and 400°C due to the recovery and recrystallization. However, in the temperature range between 450 and 650°C, the generation of vacancy clusters which trap positrons is revealed. This temperature range coincides with the temperature range of a 0 -martensite reversion which is confirmed by microhardness and magnetization measurements. The detected large vacancy clusters consisting of 6-9 vacancies can occur at the interface between austenite and a 0 -martensite phases due to the volume contraction accompanying bcc/fcc change.

show abstract

“…[10] We believe that the nucleation and growth of metal carbide precipitates, mainly M 23 C 6 type, could also provide positron trapping sites in the matrix-precipitate interfaces. [11] The purpose of the present study was to investigate the use of the PAS technique to study 1.4307 (EN) SS samples deformed by rolling at different temperatures and to a much higher degree of deformation compared to our previous studies. This allowed us to examine how the amount of a¢-martensite influenced defect formation during reverse transformation.…”

Section: Introductionmentioning

confidence: 97%

Thermal Stability of Rolled Metastable Austenitic Stainless Steel 1.4307 Studied Using Positron Annihilation

Dryzek

Sarnek

Wróbel

2018

Metall Mater Trans A

View full text Add to dashboard Cite

Positron annihilation spectroscopy (PAS) was used in the study of cumulative isochronal and isothermal annealing of rolled 1.4307 (EN) stainless steel (SS). Due to different rolling temperatures, the SS samples varied in the a¢-martensite volume fraction from 0.09 to 0.91. The measurements of positron annihilation characteristics, i.e., Doppler broadening (DB) of the annihilation line, showed a gradual annealing of vacancies in the temperature range between 200°C and 400°C, which indicated the first stage of recovery. This first stage of recovery did not change the microhardness. In the temperature range from 475°C to 600°C, a decrease in the microhardness and generation of new open volume defects accompanying the reversion of a¢-martensite to austenite was observed. The amount of these defects correlated with the initial a¢-martensite volume fraction. Their formation could be related to the volume contraction occurring during bcc/fcc transformation. The different chemical surroundings suggested that the positron trapping defects were associated with the metal carbide precipitates.

show abstract

Microstructural Characterization of Ferritic/Martensitic Steels by Positron Annihilation Spectroscopy

Cited by 13 publications

References 12 publications

Helium behavior in ferritic/martensitic steels irradiated in spallation target

Helium behavior in ferritic/martensitic steels irradiated in spallation target

Reverse transformation of deformation-induced martensite in austenitic stainless steel studied by positron annihilation

Thermal Stability of Rolled Metastable Austenitic Stainless Steel 1.4307 Studied Using Positron Annihilation

Contact Info

Product

Resources

About