Effect of hardening on the magnetic behavior of AISI 1045 steel

Vukotić, Mario (author), Miljavec, Damijan (author), Burja, Jaka (author)

Hardening is an effective method to improve the hardness of the steel construction elements of an electric machine, such as rotor shaft. Surface hardening is typically employed for shafts as it provides a material with hard wear-resistant surface (martensite) and tough and ductile core (ferrite and pearlite), with the transitional zone between them (martensite, ferrite, and pearlite). The investigations were performed on the specimens of AISI 1045 steel, which is commonly used in electric machines. There were three categories of specimens, each of them representing a region in a surface hardened shaft – normalized specimens found in as-delivered steel (core), partially hardened specimens obtained by partial hardening of normalized specimens (transitional zone), and fully hardened specimens (hardened surface), also obtained from the normalized steel. Comparison of the magnetization curves showed that partially and fully hardened specimens exhibited a decrease of saturation magnetic flux density for about 11% and 7%, respectively, compared to the normalized specimens. The magnetizing curves from this study can be directly used in the magnetic simulations of a surface-hardened shaft. This allows more accurate electromagnetic design of electric machines, in which the shaft represents an important part of the magnetic circuit, e.g. two-pole wound-rotor synchronous machine.

• Language: English
• Keywords: electric machine, hardening, hysteresis loop, magnetic properties, magnetizing curve, microstructure, shafts, steel, magnetic hysteresis, saturation magnetization, magnetic field measurement, surface treatment, magnetic circuits, ferrites
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FE - Faculty of Electrical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2025
• Number of pages: 7 str.
• Numbering: Vol. 61, no. 10, art. 2001107
• PID: 20.500.12556/RUL-174437
• UDC: 537
• ISSN on article: 1941-0069
• DOI: 10.1109/TMAG.2025.3598357
• COBISS.SI-ID: 245969155
• Publication date in RUL: 02.10.2025

Record is a part of a journal

• Title: IEEE transactions on magnetics
• Shortened title: IEEE trans. magn.
• Publisher: Institute of Electrical and Electronics Engineers
• ISSN: 1941-0069
• COBISS.SI-ID: 72410881

Licences

• License: CC BY-NC-ND 4.0, Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
• Link: http://creativecommons.org/licenses/by-nc-nd/4.0/
• Description: The most restrictive Creative Commons license. This only allows people to download and share the work for no commercial gain and for no other purposes.

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: L2-50084
• Name: Celostno načrtovanje in eksperimentalno modeliranje električnih motorjev