TY - JOUR
T1 - Detection of Non-Metallic Inclusions in Quenched and Tempered Steel Bars by XCT and after Fatigue Life Testing
AU - Gusenbauer, Christian
AU - Reiter, Michael
AU - Kastner, Johann
AU - Klösch, Gerald
N1 - Funding Information:
The presented research work was funded by the K-Project for Non-Destructive Testing and Tomography Plus financed by FFG and the government of Upper Austria and Styria and by the Metallurgical Competence Center K1-MET, which has been financially supported within the Austrian competence center program COMET by the Federal Ministry of Economy, Family and Youth; by the Federal Ministry for Transport, Innovation and Technology; by the provinces of Upper Austria, Styria, and Tyrol; by the Styrian Business Promotion Agency and by the Tiroler Zukunftsstiftung which has its focus on the modeling and simulation of metallurgical processes, including metallurgical raw materials and refractoriness with the goal of optimal process control with respect to product quality, zero waste, and the minimization of energy and raw materials.
Publisher Copyright:
© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Non-metallic inclusions (NMIs) determine to a high degree the quality and cleanness of steel and are often the reason for functional failure, especially in dynamic-stressed components. Therefore, it is important to have accurate, fast, and reliable characterization methods for these unwanted material inhomogeneities. In this paper, two different methods for the detection of NMIs are compared: X-ray-computed tomography (XCT) and fatigue life testing. XCT allows the detection and analysis of material inhomogeneities and their positions in a 3D volume. The evaluation of XCT-data of Fe-based materials can be rather difficult, since the results are usually prone to image noise, offer poor contrast, and the interpretation is affected by artifacts. Suitable evaluation strategies for detection and classification are presented. The degradation of steel samples by dynamic fatigue testing is a destructive way of determining the existence of harmful NMIs. If there is an NMI of critical size in the sample, a functional failure may occur. The fracture surface is investigated by scanning electron microscopy (SEM), equipped with an energy dispersive X-ray (EDX) spectroscopy unit in order to identify shape, type, and chemical composition of the harmful NMI. This paper deals with the production, detection, and identification of harmful NMIs in steel bars by means of XCT and fatigue life testing and the subsequent inspection of the resulting fracture surface by SEM and EDX. These characterization methods enable NMI design by modifying its chemical composition during secondary metallurgical processing and thus improving steel cleanness.
AB - Non-metallic inclusions (NMIs) determine to a high degree the quality and cleanness of steel and are often the reason for functional failure, especially in dynamic-stressed components. Therefore, it is important to have accurate, fast, and reliable characterization methods for these unwanted material inhomogeneities. In this paper, two different methods for the detection of NMIs are compared: X-ray-computed tomography (XCT) and fatigue life testing. XCT allows the detection and analysis of material inhomogeneities and their positions in a 3D volume. The evaluation of XCT-data of Fe-based materials can be rather difficult, since the results are usually prone to image noise, offer poor contrast, and the interpretation is affected by artifacts. Suitable evaluation strategies for detection and classification are presented. The degradation of steel samples by dynamic fatigue testing is a destructive way of determining the existence of harmful NMIs. If there is an NMI of critical size in the sample, a functional failure may occur. The fracture surface is investigated by scanning electron microscopy (SEM), equipped with an energy dispersive X-ray (EDX) spectroscopy unit in order to identify shape, type, and chemical composition of the harmful NMI. This paper deals with the production, detection, and identification of harmful NMIs in steel bars by means of XCT and fatigue life testing and the subsequent inspection of the resulting fracture surface by SEM and EDX. These characterization methods enable NMI design by modifying its chemical composition during secondary metallurgical processing and thus improving steel cleanness.
KW - X-ray-computed tomography
KW - fatigue life testing
KW - micro-structure characterization
KW - steel
UR - http://www.scopus.com/inward/record.url?scp=84959566323&partnerID=8YFLogxK
U2 - 10.1002/srin.201500083
DO - 10.1002/srin.201500083
M3 - Article
VL - 87
SP - 386
EP - 393
JO - steel research international
JF - steel research international
IS - 3
ER -