Obtaining Excellent Mechanical Properties in an Ultrahigh-Strength Stainless Bearing Steel via Solution Treatment

Bibliographic Details
Title: Obtaining Excellent Mechanical Properties in an Ultrahigh-Strength Stainless Bearing Steel via Solution Treatment
Authors: Kai Zheng, Zhenqian Zhong, Hui Wang, Haifeng Xu, Feng Yu, Cunyu Wang, Guilin Wu, Jianxiong Liang, Andy Godfrey, Wenquan Cao
Source: Metals, Vol 13, Iss 11, p 1824 (2023)
Publisher Information: MDPI AG, 2023.
Publication Year: 2023
Collection: LCC:Mining engineering. Metallurgy
Subject Terms: solution treatment, retained austenite, TRIP effect, dislocation strengthening, precipitation strengthening, Mining engineering. Metallurgy, TN1-997
More Details: A novel versatile ultrahigh-strength stainless bearing steel was prepared by first solution treating the steel at temperatures between 1000 °C and 1100 °C for 1 h, followed by performing cryogenic treatment at −73 °C for 2 h, and tempering at 500 °C for 2 h, with the cryogenic and tempering treatments being repeated twice. The microstructures were characterized using multiscale techniques, and the mechanical properties were investigated using tensile testing, as well as via Rockwell hardness and impact toughness measurements. Tensile strength was found to be independent of solution temperature, with a value of about 1800 MPa. In contrast, yield strength decreased from 1530 MPa to 1033 MPa with increasing solution temperature, while tensile elongation increased from 15.3% to 20.5%. This resulted in an excellent combined product of tensile strength and elongation for steels initially treated at 1080 °C and 1100 °C, with values of 33.9 GPa·% and 37.0 GPa·%, respectively. Furthermore, the steels showed excellent impact toughness, increasing from 37.0 J to 86.2 J with increasing solution temperature. The microstructural and mechanical investigations reveal that the excellent mechanical properties and impact toughness are related to three factors, namely (i) a transformation-induced plasticity effect, mainly attributed to a high volume fraction of retained austenite, (ii) a high strengthening capacity arising from a high dislocation density, and (iii) a synergistic effect due to cobalt additions and the nanoprecipitation of M2C and M6C carbides.
Document Type: article
File Description: electronic resource
Language: English
ISSN: 2075-4701
Relation: https://www.mdpi.com/2075-4701/13/11/1824; https://doaj.org/toc/2075-4701
DOI: 10.3390/met13111824
Access URL: https://doaj.org/article/d7d9a3af90be4c0b9a6610a5a4d32fe4
Accession Number: edsdoj.7d9a3af90be4c0b9a6610a5a4d32fe4
Database: Directory of Open Access Journals
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More Details
ISSN:20754701
DOI:10.3390/met13111824
Published in:Metals
Language:English