Detection and evaluation of material degradation of thermally aged duplex stainless steels: electrochemical polarization test and AFM surface analysis

Yi, Yongsun; Shoji, Tetsuo

doi:10.1016/0022-3115(96)00361-3

Cited by 38 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Some of them reported the mechanism of the effect of thermal aging on pitting corrosion or intergranular corrosion 12,20 . In others, the researches on the chemical or electrochemical of thermally aged DSS only were used to evaluate the material degradation induced by thermal aging 21,22 . However, on one hand, a few attempts have been taken to discuss the effect of different thermal aging temperature on the pitting resistance of them, especially for the DSS thermally aged for a long time.…”

Section: Introductionmentioning

confidence: 99%

Pitting Corrosion of Thermally Aged Duplex Stainless Steels at Different Temperature for Long Time

Wang

Sun

et al. 2019

Mat. Res.

View full text Add to dashboard Cite

The pitting corrosion of three duplex steels (DSS), SAF2205, SAF2507, Z3CN20.09M thermally aged at 350-500 ℃ for 5500 h was investigated by the means of electrochemical techniques. The pitting potential (E p) of thermally aged Z3CN20.09M specimens decreased with increasing of ageing temperature, however, the E p of SAF2205 and SAF2507 thermally aged specimens decreased first and reached the lowest value at 450 ℃ and then increased slightly. The electrochemical impedance spectroscopy results are coincident with the potentiodynamic polarisation testing results. The variation in the charge transfer resistance of specimens coincided with the E p values. There is little influence of low temperature (below 350 ℃) on resistance to pitting of SAF2205 and SAF2507 DSS. But, the pitting resistance of them degrades drastically ageing at higher temperature above 450 ℃. The deterioration in pitting resistance of thermally aged DSS specimens mainly attributes to the precipitation of Cr-rich α′ phases which affected by temperature markedly. At the range of 350-500 ℃, the temperature the higher, the precipitation of Cr-rich α′ phases the more. The formation of G phases and the healing process during the long thermal ageing at 500 ℃ is the other reasons for the change in pitting resistance.

show abstract

Section: Introductionmentioning

confidence: 99%

Pitting Corrosion of Thermally Aged Duplex Stainless Steels at Different Temperature for Long Time

Wang

Sun

et al. 2019

Mat. Res.

View full text Add to dashboard Cite

show abstract

“…Ensaios de tenacidade ao impacto e dureza permitem identificar se a fase α sofreu ou não decomposição [8,9,[11][12][13][14]. Além disso, técnicas de análise não destrutivas como é o caso do uso de ultrassom [14] e observações de aspectos que distinguem aços inoxidáveis duplex solubilizados de envelhecidos com o uso de microscopia de varredura por sonda mecânica têm sido exploradas [15][16][17][18][19]. Neste trabalho, a evolução da fragilização a 475ºC em um aço inoxidável lean duplex foi estudada por microscopia de força atômica.…”

Section: Introductionunclassified

Utilização Da Microscopia De Força Atômica No Estudo Da Fragilização a 475ºc Em Um Aço Inoxidável Lean Duplex

Reis¹,

Godefroid²,

Andrade³

2018

ABM Proceedings

View full text Add to dashboard Cite

ResumoNeste trabalho, a microscopia de força atômica foi empregada para estudo da evolução da fragilização a 475ºC em um aço inoxidável lean duplex. Para tal, amostras deste aço foram submetidas a tratamentos isotérmicos com duração variando entre 1 e 100 horas na temperatura de 475ºC. Ensaios de tenacidade ao impacto e de dureza foram realizados para confirmar a ocorrência da decomposição da fase α. Posteriormente foram realizadas análises no microscópio de força atômica. Os ensaios de tenacidade ao impacto e de dureza indicaram que ocorreu decomposição espinodal da fase α. Medições da diferença da dissolução das fases α e γ, conduzidas no microscópio de força atômica, indicaram que a resistência à dissolução da fase α diminui com o tempo de envelhecimento de forma similar a redução da tenacidade. Os resultados indicam que a microscopia de força atômica é uma ferramenta eficiente para avaliar o grau de evolução da fragilização a 475ºC. Palavras-chave: Microscópio de força atômica; Aços inoxidáveis duplex; Fragilização a 475ºC; Fase α'. USING OF ATOMIC FORCE MICROSCOPY TO STUDY OF THE EMBRITTLEMENT AT 475ºC OF A LEAN DUPLEX STAINLESS STEEL AbstractIn this work, the atomic force microscopy was employed to study the evolution of the embrittlement at 475ºC of a lean duplex stainless steel. For this, samples of this steel were subjected to isothermal treatments with duration between 1 to 100 hours in the temperature of 475ºC. Tests of impact toughness and hardness were carried out to confirm the occurrence of α phase decomposition. Atomic force microscopy analyzes were performed. The impact toughness and hardness tests indicated that α spinodal decomposition has occurred. Measurements of the difference in α and γ phases dissolution, carried out by atomic force microscopy, indicated that the α phase dissolution resistance decreased with time of ageing in the same way as the toughness reduction. The results indicated that the atomic force microscope is an efficient tool to assess the evolution of the embrittlement at 475ºC.

show abstract

“…Cast austenitic stainless steels (CASS), which are characterized by the dual phase microstructure in which the island α-ferrite phase distributes in the γ-austenite matrix, possess excellent synthesis mechanical properties, good workability and high resistance to localized corrosion in chloride environments [1][2][3][4] . Consequently, they are widely used in the primary coolant pipes of nuclear power plants and other engineering applications such as oil, chemical petrochemical, marine industries.…”

Section: Introductionmentioning

confidence: 99%

Effect of Ferrite on the Precipitation of σ Phase in Cast Austenitic Stainless Steel Used for Primary Coolant Pipes of Nuclear Power Plants

Wang

2017

Mat. Res.

View full text Add to dashboard Cite

The effect of ferrite phase on the precipitation of σ phase in a Z3CN20.09M cast austenitic stainless steel (CASS) used for primary coolant pipes of pressurized water reactor (PWR) nuclear power plants was investigated by using isothermal heat-treatment, optical microscopy (OM), transmission electron microscopy (TEM) and electron probe microanalysis (EPMA) techniques. The influence of different morphologies and volume fractions of ferrite in the σ phase formation mechanism was discussed. The amount of σ phase precipitated in all specimens with different microstructures increased with increasing of aging time, however, the precipitation rate is significant different. The formation of σ phase in specimens with the coarsest ferrite and the dispersively smallest ferrite is slowest. The lowest level Cr content in ferrite and fewest α/γ interfaces in specimen are the main reasons for the slowest σ precipitation due to they are unfavorable for the kinetics and thermodynamics of phase transformation respectively. By contraries, the fastest formation of σ phase takes place in specimens with narrow and long ferrite due to the most α/γ interfaces and higher Cr content in ferrite which are beneficial for preferential nucleation and formation thermodynamics of σ phase.

show abstract

Detection and evaluation of material degradation of thermally aged duplex stainless steels: electrochemical polarization test and AFM surface analysis

Cited by 38 publications

References 9 publications

Pitting Corrosion of Thermally Aged Duplex Stainless Steels at Different Temperature for Long Time

Pitting Corrosion of Thermally Aged Duplex Stainless Steels at Different Temperature for Long Time

Utilização Da Microscopia De Força Atômica No Estudo Da Fragilização a 475ºc Em Um Aço Inoxidável Lean Duplex

Effect of Ferrite on the Precipitation of σ Phase in Cast Austenitic Stainless Steel Used for Primary Coolant Pipes of Nuclear Power Plants

Contact Info

Product

Resources

About