Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
Monitoring the 475ºC Embrittlement by Barkhausen Noise Measurements in a Duplex Stainless Steel
Submission Author:
Alisson Alves dos Santos , PB
Co-Authors:
Alisson Alves dos Santos, Filipe Fragoso de Abreu, Edgard Silva, Walter Fialho, Michelline Nery Azevedo Lima
Presenter: Alisson Alves dos Santos
doi://10.26678/ABCM.COBEM2023.COB2023-0876
Abstract
Duplex stainless steel (DSS) have been largely used as a structural material in various engineering sectors, such as pulp and paper industries and oil and gas industries. The microstructure of DSS is formed by balanced proportions of austenite and ferrite. This combination provides high levels of strength and corrosion resistance. However, this material suffers from the so-called 475 ºC embrittlement when exposed to temperatures between 280-500 ºC. Previous studies point out that this embrittlement happens through spinodal decomposition, a spontaneous phase transformation phenomenon. To avoid accidents in DSS structures in service, nondestructive testing are needed to detect the embrittled phase and prior intervention on the equipments. Magnetic Barkhausen Noise (MBN) has been used for parameter survey in tests of this type. When ferromagnetic material is exposed to a alternating magnetic field, MBN is emitted due to the interaction between the magnetic domain walls and microscopic anchor points. In this work, electromagnetic testing based on MBN detection is used for monitoring the embrittlement. The data obtained was compared to Charpy impact testing and Rockwell C hardness measurements. The results showed that there is a direct correlation between the two destructive tests and the RMS values obtained by MBN, indicating that the 475 ºC embrittlement can be detected using this technique.
Keywords
duplex stainless steel, magnetic Barkhausen noise, nondestructive testing, 475 ºC embrittlement
