Banca de QUALIFICAÇÃO: IZAURA LUIZ VIEGAS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : IZAURA LUIZ VIEGAS
DATE: 17/12/2021
TIME: 14:00
LOCAL: Remoto
TITLE:

Characterization of Sine Waves Capable of Detecting the Sigma Deleterious Phase Concentration, Through the RMB Analysis in Duplex Stainless Steel Samples with Different Thicknesses

KEY WORDS:

Samples, Duplex Stainless Steel (DSS), Non-Destructive Testing (NDT), Thickness ,Sigma Phase (σ), Barkhausen Magnetic Noise (MBN).

PAGES: 50
BIG AREA: Engenharias
AREA: Engenharia Elétrica
SUBÁREA: Telecomunicações
SPECIALTY: Teoria Eletromagnetica, Microondas, Propagação de Ondas, Antenas
SUMMARY:

Ferromagnetic materials are commonly used in the most diverse areas of the industrial sector. Techniques for mechanical tests are used to inspect the mechanical properties of materials. In this field of testing, Barkhausen Magnetic Noise (MBN) is used as a Non-Destructive Testing (NDT) technique for ferromagnetic materials. The study of the MBN generated from the application of a magnetic field (H) that passes through a sample of a ferromagnetic material, promotes the displacement of the walls of the magnetic domains that, when moving, collide with microstructures or incrustations present inside the material, this shock produces electrical voltage peaks that can be measured in rms values and correlated to some mechanical properties of the material. Based on the generation of MBN noise, a non-destructive electromagnetic test with the emitter coil located on the opposite surface of the receiver coil is proposed as a technique for identifying the characteristics of the best sine wave capable of generating the MBN in the receiver coil that identifies the sigma phase present in samples of Duplex Stainless Steel (DSS) SAF 2205, of circular geometry, of equal diameters, different thicknesses and with different percentages of the sigma phase. This sigma phase weakens the material and compromises important properties such as corrosion resistance and tenacity. In a preliminary phase, sinusoidal-shaped emitting waves were used at frequencies 5 Hz, 15 Hz, 20Hz,25 Hz, 50 Hz, 75 Hz and 100 Hz and voltage amplitude 1 V, 3V, 5V, 7V and 9V applied to samples with and no sigma precipitate, 4 mm and 8 mm thickness. The behavior of the MBN is measured in rms values after the wave passes through the material sample and detected in the receiver coil. The ratio between the modulus variation of the difference in rms values between the two conditions of the samples when related to the rms values of samples with the sigma phase demonstrates that it is possible to use waves with frequencies of 5 Hz and 15 Hz in 4 mm samples and for 8 mm samples, the use of frequencies up to 50 Hz is evidenced. The test proved capable of characterizing the parameters of the best sine wave that can be used in these working conditions to detect the presence of the sigma phase.

BANKING MEMBERS:
Presidente - 1422265 - JOSE PATROCINIO DA SILVA
Interno - 3921178 - VALDEMIR PRAXEDES DA SILVA NETO
Externo à Instituição - EDGARD DE MACEDO SILVA - IFPB