Journal: IJE Transactions B
Publication date: 15 February 2015
Abstract:
Two nondestructive electromagnetic/magnetic techniques including hysteresis loop and eddy current methodologies have been used to characterize microstructural changes of AISI D2 cold work tool steel as a result of quench and tempering treatments. Read more
Journal: Journal of Magnetism and Magnetic Materials
Publication date: 7 February 2015
Abstract:
The present paper investigates the potential of using eddy current technique as a reliable nondestructive tool to detect microstructural changes during the different stages of tempering treatment in AISI D2 tool steel. Read more
Journal: Journal of Materials Engineering and Performance
Publication date: 21 January 2015
Abstract:
Inaccurate heat treatment process could result in excessive amount of retained austenite, which degrades the mechanical properties, like strength, wear resistance, and hardness of cold work tool steel parts. Thus, to control the mechanical properties, quantitative measurement of the retained austenite is a critical step in optimizing the heat-treating parameters. X-ray diffraction method is the most frequently used technique for this purpose. Read more
Journal: Iranian Journal of Science and Technology-Transactions of Mechanical Engineering
Publication date: 16 June 2014
Abstract:
The present research investigates improvement of Eddy Current (EC) technique as a nondestructive method for measurement of ductile cast iron microstructural and mechanical characteristics. Read more
Journal: Nondestructive Testing and Evaluation
Publication date: 29 Apr 2014
Abstract:
The present paper describes details of the comparison on the capability of eddy current (EC) and magnetic Barkhausen noise (MBN) techniques in the assessment of different microstructures in mild steel. Read more
Journal: Metal Science and Heat Treatment
Publication date: 30 November 2013
Abstract:
Cast iron with globular graphite is studied after surface induction hardening. Hardness profiles of iron bars are plotted for determining the thickness of the hardened layer. Relations between the thickness of the hardened layer and the output voltage are obtained by the method of dual frequency (induced voltage and normalized impedance) for checking the applicability of the eddy current method. The correlation coefficient and the error of the evaluation of the thickness of the hardened layer are determined with the help of the relations obtained.
Journal: Materials Science and Technology
Publication date: 18 Nov 2013
Abstract:
Machinability of grey cast iron parts can greatly suffer from the formation of carbide at the surface, resulting in a decrease in cutting tool life and higher production costs. Therefore, detection of the hardened layer and its hardness are the key factors in quality control and inspection processes. In the present paper, a number of metallurgical parameters (surface carbide, surface hardness and hardened depth) have been investigated using the non-destructive differential eddy current technique. The results show the high potential of the proposed method as a fast and accurate technique in inspecting and in consequent separation of undesirable parts. Read more
Journal: Journal of Materials Engineering and Performance
Publication date: 15 September 2012
Abstract:
Inspection and quality control of induction hardened parts require a good understanding of the depth of the hardened layer. Traditional destructive methods to determine the case depth are considered to be costly and time-consuming. The eddy current (EC) technique is sensitive to micro-structural changes; hence, it can be used to determine the case depth based on the differences in magnetic properties between the hardened layer and the core of the specimen. In this study, identical rods of AISI 1045 mild carbon steel were surface hardened using induction hardening technique. In order to investigate the applicability of the EC technique, the relations between obtained effective and total case depths and the EC outputs (induced voltage, normalized impedance, phase angle, and their harmonic characteristics) were studied. The results show a maximum of correlation coefficient of 94% in determining case depths by EC technique.