Microstructural characterization of hypoeutectoid steels quenched from the Ae1 - Ae3 intercritical temperature range by magnetic barkhausen noise technique

Download

index.pdf

Date

2006

Author

Boyacıoğlu, Beril

Metadata

Show full item record

Item Usage Stats

225
views

94
downloads

This thesis aims to examine the possibility of using Magnetic Barkhausen Noise technique in characterizing the ferritic-martensitic microstructure of hypoeutectoid steels quenched from the intercritical temperature range. For this purpose, rectangular specimens were prepared from SAE 1020, 1040 and 1060 steels. The specimens were heated at different temperatures within the intercritical temperature range and then quenched into water. Microstructures of the specimens were characterized by metallographic examinations and hardness measurements. The measurements of the Magnetic Barkhausen Noise (MBN) were performed by using both Rollscan and æSCAN sensor connectors. It was seen that, for specimens having identical carbon content, Barkhausen emission decreased as the heating temperature increased. Moreover, in specimens heated at the same temperature, Barkhausen emission decreased as the carbon content of the specimen increased. In both cases, the decrease in Barkhausen emission is associated with the increase in martensite content. The results indicate that MBN is inversely proportional to hardness and that MBN is very sensitive to the microstructural condition of the material. It has been shown that using MBN is a powerful tool for evaluating the microstructure of hypoeutectoid steels quenched from the intercritical temperature range and that the use of this technique could be extended to characterize industrial dual phase steels.

Subject Keywords

Metallurgy.

URI

http://etd.lib.metu.edu.tr/upload/12606921/index.pdf
https://hdl.handle.net/11511/15683

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Characterization of steel microstructures by magnetic barekhausen noise technique Davut, Kemal; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2006) This aim of this thesis is to examine the possibility of using Magnetic Barkhausen Noise (MBN) technique in characterizing the microstructures of quenched and tempered low alloy steels as well as annealed low carbon steels. To determine the average grain size by MBN, SAE 1010 steel consisting of dominantly ferrite was used. The specimens were slowly cooled in the furnace after austenitizing at different time and temperature variations. By metallographic examination the average ferrite grain size of specimen...
Theoretical and experimental investigation of bulk glass forming ability in bulk amorphous alloy systems Ayas, Can; Mekrabov, Amdulla O.; Department of Metallurgical and Materials Engineering (2005) In this study molecular dynamics simulation program in NVT ensemble using Velocity Verlet integration was written in order to investigate the glass forming ability of two metallic systems. The Zn-Mg system, one of the frontiers of simple metal-metal metallic glasses and Fe-B, inquiring attention due to presence of many bulk glass forming alloy systems evolved from this binary with different alloying element additions. In addition to this, atomistic calculations on the basis of ordering were carried out for ...
Characterization of maghemite thin films prepared by sol-gel processing Karakuşçu, Aylin; Özenbaş, Ahmet Macit; Department of Metallurgical and Materials Engineering (2006) In this study, maghemite (γ-Fe2O3) thin films were prepared by chemical solution deposition on glass and quartz substrates. The solution was prepared by using 0.3 M iron (III) nitrate [Fe(NO3)3 - 9H2O] as precursor and dissolved in a mixture of 2-methoxyethanol and acetylacetone in a molar ratio of 20:2, by stirring the solution at RT for 2 hours. Substrates were prepared by either piranha etching method or ultrasonic cleaning method. The solution was spin coated on glass and quartz substrates at 1400 and 4...
Influence of B2O3 additions on the microstructure of mica based glass-ceramics Aykut, Hakan; Öztürk, Abdullah; Department of Metallurgical and Materials Engineering (2005) Mica based glass - ceramics have been produced by subjecting the glasses in the SiO2 , Al2O3 , CaO , MgO, K2O , and F system to a controlled heat treatment called crystallization. TiO2 was added into the batch in the amount of 1 wt% of the glass as nucleating agent. B2O3 additions in the amounts of 1, 2, 4 and 8 wt% of the glass have been made in the batch to see and evaluate the effects of B2O3 additions on the texture of the mica glass ceramics. Crystallization was accomplished in two steps, nucleation an...
Investigation of the effect of orientation and heat treatment on the stress corrosion cracking susceptibility of 7050 aluminium alloy Çevik, Gül; Doruk, Mustafa; Department of Metallurgical and Materials Engineering (2004) In the present work, the effect of variation in specimen orientation and heat treatment on the Stress Corrosion Cracking (SCC) susceptibility of 7050 aluminum alloy was investigated in 3,5% NaCl solution and under freely corroding conditions. For this purpose, Constant Extension Rate Tests (CERT) was performed on precracked Compact Tension (CT) specimens and the Direct Current Potential Drop technique was applied to measure the crack lengths. In addition to crack length versus time curves, the relationship ...

Citation Formats

B. Boyacıoğlu, “Microstructural characterization of hypoeutectoid steels quenched from the Ae1 - Ae3 intercritical temperature range by magnetic barkhausen noise technique,” M.S. - Master of Science, Middle East Technical University, 2006.