Nondestructive monitoring of the variations in microstructure and residual stress in carburized steels

Download
2016
Hızlı, Hüseyin
Service life and performance of the case-hardened machine parts are greatly dependent on the residual stress state in the surface layers which directly affects the fatigue behavior. Recently, all industrial sectors have been requested for a fast and non-destructive determination of residual stress. This study aims to monitor the variations in surface residual stress distributions in the carburized 19CrNi5H steels by means of non-destructive and semi-destructive measurement techniques, Magnetic Barkhausen Noise (MBN), X-Ray Diffraction (XRD), and Electronic Speckle Pattern Interferometry (ESPI) assisted hole drilling. Microstructural investigation by optical and scanning electron microscopy, hardness measurements, and spectroscopy analysis were also conducted. To comprehend the differences in the residual stress distributions, various samples were prepared by applying different duration of carburizing and tempering temperatures. Residual stress measurements carried out by XRD and ESPI assisted hole drilling showed that the compressive residual stress state exists for the case-hardened samples throughout the case depth regions, and the magnitude of the compressive residual stress decreases as the tempering temperature increases. MBN measurements showed that the BN activity increases with decreasing carburization time and increasing tempering temperature. It was concluded that MBN technique could be used to measure the surface residual stress distributions with a proper calibration operation. 

Suggestions

Comparison of Nondesturctive Stress Measurement Techiques for Determinatuion of Residual Stresses in the Heat Treated Steels
Hizli, Huseyin; Gür, Cemil Hakan (MATERIALS RESEARCH FORUM LLC, 105 SPRINGDALE LN, MILLERSVILLE, PA 17551 USA; 2018-09-14)
Service life and performance of the case-hardened machine parts are greatly dependent on the residual stress state in the surface layers which directly affects the fatigue behavior. Recently, all industrial sectors have been requested for a fast and non-destructive determination of residual stress. This study aims to monitor of the variations in surface residual stress distributions in the carburized 19CrNi5H steels by means of non-destructive and semi-destructive measurement techniques, Magnetic Barkhausen...
Determination of residual stress state in SAE/AISI 8620 carburized steel by non-destructive testing methods
Kaleli, Tuğçe; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2017)
Industrial performance of the carburized steels is mainly dependent on the residual stress state in the carburized layer that is controlled by the process parameters such as carburizing temperature and time. Non-destructive evaluation of the material properties and residual stress state has been gained importance for industrial applications due to its advantages such as measurement speed and complete control possibility of the components by automation. The aim of this thesis is to investigate the efficiency...
Measurement of residual stresses in the carburized steels by non destructive techniques
Hızlı, Hüseyin; Kaleli, Tuğçe; Gür, Cemil Hakan (null; 2016-10-01)
Residual stress state on the surface layers has a critical effect on the service performance and fatigue life of the carburized components. Non-destructive determination of residual stress state in a rapid and reliable way has being gained importance for industrial applications. The aim of this study is to investigate the efficiency of the magnetic Barkhausen noise (MBN) method for monitoring the residual stress variations as a function of carburizing process parameters. For this purpose, MBN and XRD measur...
Determination of shot peening effect on fatigue behavior of AISI 4140 steel by non-destructive measurement of surface residual stresses
Çalışkan, Salim; Gür, Cemil Hakan; Department of Metallurgical and Materials Engineering (2018)
The fatigue performance of aircraft parts can be improved by inducing compressive residual stresses in the near-surface zone by shot-peening. The depth profile and the magnitude of residual stresses depend on the shot peening parameters. Aircraft industry requires an easy and rapid non-destructive method for determination of residual stress state to verify the achievement of the desired results of shot-peening. This study aims to determine nondestructively the residual stresses at the surface by the Magneti...
Non-destructive evaluation of residual stresses in the multi-pass steel weldments
Erian, Gökhan; Gür, Cemil Hakan; Batıgün, Caner; Department of Metallurgical and Materials Engineering (2012)
The purpose of this thesis is non-destructive determination of residual stress state in the multi-pass welded steel plates by Magnetic Barkhausen Noise (MBN) technique. To control the effectiveness of the developed procedure, continuous MBN measurements on the heat affected zone and parent metal of the welded plates were performed. In the experimental part, various steel plates were welded with different number of weld passes. Various series of samples were prepared for residual stress and for angular defle...
Citation Formats
H. Hızlı, “Nondestructive monitoring of the variations in microstructure and residual stress in carburized steels,” M.S. - Master of Science, Middle East Technical University, 2016.