Back to Search Start Over

Enhanced Spring Steel’s Strength Using Strain Assisted Tempering

Authors :
Zbyšek Nový
Pavel Salvetr
Jakub Kotous
Petr Motyčka
Aleksandr Gokhman
Črtomir Donik
Ján Džugan
Source :
Materials, Vol 15, Iss 20, p 7354 (2022)
Publication Year :
2022
Publisher :
MDPI AG, 2022.

Abstract

Spring steels are typical materials where enhancement of mechanical properties can save considerable mass for transport vehicles, in this way the consumption of fuel or electric energy can be decreased. A drastic change in both the resulting microstructure and mechanical properties could be achieved due to the inclusion of strain into the tempering process after quenching. The strain assisted tempering (SAT) technology was applied, i.e., the process of quenching and following a sequence of tempering operations alternating with strain operations. After the first tempering, controlled deformation by rotary swaging was carried out with a strain of 17% (strain rate is about 120 s−1). Considerably higher strength parameters after SAT compared to conventional quenching and tempering (QT) technology were nevertheless accompanied by enhanced notch toughness at the same time by the decrease of elongation and reduction of area. However, by optimizing the process it is was also possible to achieve acceptable values for those parameters. Remarkable differences are visible in resulting microstructures of compared samples, which were revealed by metallographic analysis and X-ray diffraction measurement. While the standard microstructure of tempered martensite with transition carbides was observed after QT processing, carbideless islands with nanotwins occurred in martensitic laths after SAT processing.

Details

Language :
English
ISSN :
19961944
Volume :
15
Issue :
20
Database :
Directory of Open Access Journals
Journal :
Materials
Publication Type :
Academic Journal
Accession number :
edsdoj.05ba8c72452442e8565bfb8d8e82d70
Document Type :
article
Full Text :
https://doi.org/10.3390/ma15207354