Monitoring the Microstructural Evolution in Spheroidized Steels by Magnetic Barkhausen Noise Measurements

DAVUT, Kemal
Gür, Cemil Hakan
The aim of this study is to monitor nondestructively the degree of spheroidization in steels by Magnetic Barkhausen Noise (MBN) method. Various series of specimens consisting of either lamellar pearlite or partially/completely spheroidized carbides were produced from AISI 1060 steel by appropriate heat treatments. All specimens were characterized by metallographic examinations, hardness and MBN measurements. The results show that MBN signals are very sensitive to the variations in the microstructure caused by the spheroidizing heat treatment. The change of microstructure, from coarse lamellar carbides to uniformly dispersed spherical carbides in ferrite matrix, is reflected as higher Barkhausen activity due to less effective pinning of domain walls.


Monitoring the microstructural changes during tempering of quenched SAE 5140 steel by magnetic barkhausen noise
Davut, Kemal; Gür, Cemil Hakan (Springer Science and Business Media LLC, 2007-12-01)
The aim of this work is to characterize the microstructures of quenched and tempered steels non-destructively by a diverse set of parameters of the Magnetic Barkhausen Noise method (MBN fingerprint, frequency spectra, pulse height distribution, root-mean-square, and total number of pulses). Identical specimens from a SAE 5140 steel bar were prepared. All specimens were austenitized at 860 degrees C for 30 minutes and water-quenched identically. The quenched specimens were then tempered at various temperatur...
Comparison of magnetic Barkhausen noise and ultrasonic velocity measurements for microstructure evaluation of SAE 1040 and SAE 4140 steels
Gür, Cemil Hakan; Çam, İbrahim (Elsevier BV, 2007-05-01)
The aim of this study is to compare the performance of magnetic Barkhausen noise and ultrasonic methods for the evaluation of the microstructure of commercial steels. Following the austenitization of the specimens made of SAE 1040 and SAE 4140, various heat treatments were carried out to obtain microstructures consisting of martensite, tempered martensite, fine pearlite-ferrite, and coarse pearlite-ferrite. The microstructures were initially characterized by SEM investigation and hardness measurements. The ...
Characterization of dual-phase steels using magnetic barkhausen noise technique
KAPLAN, MÜCAHİT; Gür, Cemil Hakan; Erdogan, METEHAN (Springer Science and Business Media LLC, 2007-12-01)
The aim of this work is to nondestructively characterize the dual phase steels using the Magnetic Barkhausen Noise (MBN) method. By quenching of AISI 8620 steel specimens having two different starting microstructures, from various intercritical annealing temperatures (ICAT) in the ferrite-austenite region, the microstructures consisting of different volume fractions of martensite with morphological variations have been obtained. The microstructures were first conventionally characterized by metallographical...
Performance of polylactide against UV irradiation: Synergism of an organic UV absorber with micron and nano-sized TiO2
CAN, ULAŞ; Kaynak, Cevdet (SAGE Publications, 2020-08-01)
The main purpose of this study was to investigate mechanical and thermal performance of polylactide specimens against UV irradiation; first when only adding benzotriazole benzotriazole-based organic UV absorber (UVA), micro (200 nm) and nano (50 nm) sized titania (TiO2) particles alone, and then to reveal possible synergism when they are added together. Compounds were prepared by twin-screw extruder melt mixing, while the 2 mm thick specimens were shaped by compression molding. Specimens were exposed to UV ...
Development of test structures and methods for characterization of MEMS materials
Yıldırım, Ender; Arıkan, Mehmet Ali Sahir; Department of Mechanical Engineering (2005)
This study concerns with the testing methods for mechanical characterization at micron scale. The need for the study arises from the fact that the mechanical properties of materials at micron scale differ compared to their bulk counterparts, depending on the microfabrication method involved. Various test structures are designed according to the criteria specified in this thesis, and tested for this purpose in micron scale. Static and fatigue properties of the materials are aimed to be extracted through the ...
Citation Formats
K. DAVUT and C. H. Gür, “Monitoring the Microstructural Evolution in Spheroidized Steels by Magnetic Barkhausen Noise Measurements,” JOURNAL OF NONDESTRUCTIVE EVALUATION, pp. 241–247, 2010, Accessed: 00, 2020. [Online]. Available: