Influence of the microstructure on the degree of sensitization of a duplex stainless steel UNS S31803 aged at 650ºC

Materials Research

Evelin Barbosa De Mélo²  Rodrigo Magnabosco¹  Carlos De Moura Neto² 

[1] ,Technological Institute of Aeronautics Department of Mechanical Engineering São José dos Campos SP ,Brazil

关键词: duplex stainless steel;    DL-EPR;    degree of sensitization;    sigma phase;   

DOI  :  10.1590/S1516-14392013005000125

来源: SciELO

【 摘 要 】

This work evaluates the phase transformations during aging of an UNS S31803 DSS at 650ºC and its influence on the DOS. The material was solution treated at 1175ºC and then aged at 650ºC for times up to 360 h. SEM-BSC images indicate the formation of Cr2N, σ and χ phases in the samples aged at 650ºC. The analysis of DL-EPR curves, obtained in a 1 M H2SO4 + 0.25 M NaCl + 0.01 M KSCN solution, shows an increase in DOS values for samples aged at 650ºC. Probably, this increase observed in DOS values is mainly related to the presence of Cr- and/or Mo-depleted α, as a result of σ phase, χ phase and/or Cr2N formation at 650ºC. Moreover, a possible healing up of Cr- and/ or Mo-depleted areas is observed between 1 h and 4 h of aging at 650ºC.

【 授权许可】

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