Following the duplex stainless steel embrittlement through analysis of Barkhousen noise
Edgard de Macedo Silva1; José Adeilton de Carvalho Filho1; Jose Hernando Bezerra Barreto2; Josinaldo Pereira Leite3; João Pereira Leite4; Ana Lucia Silva Souza Andrade5; Hicaro Felipe Brasileiro de Macedo Silva6
1 Instituto Federal de Educação Ciência e Tecnologia da Paraíba; 2 Instituto Federal de Educação Ciência e Tecnologia do Ceará; 3 Universidade Federal da Paraíba; 4 Universidade Federal de Campina Grade; 5 Instituto Federal de Eduação Ciência e Tenologia da Paraíba; 6 UFPB
doi:10.20906/CPS/COB-2015-1646
Resumo
The duplex stainless steel when subjected to temperatures below 550 ° C its ferrite matrix decomposes forming finely dispersed precipitates inside this phase, hardening the material and reducing the toughness. Samples of a duplex stainless steel SAF 2205 duplex were treated at temperatures of 425 ° C and 475 ° C for times up to 200 hours in order to obtain different degrees of embrittlement. A non-destructive methodology based on interaction between density of field lines and material, in the irreversibility region of magnetic domains, was developed. This one looks for a relationship between the Barkhousen noise and the embrittlement of the material. Fields with different frequencies were applied to the material by a solenoid and the resultant signal obtained by another one. The value of the largest amplitude of the Barkhousen noise was used as a measurement parameter to characterize the embrittlement of the material. Rockwell hardness tests and Charpy impact test were performed. The results showed that the amplitude of the noise as the parameter was able to follow the embrittlement of the material under investigation in both temperatures.
Palavras-chave: Barkhousen noise; duplex stainless steel; non-destructive methodology