TY - GEN

T1 - On the origin of ultra-hardness in bearing steels

T2 - 2012 AIST Steel Properties and Applications Conference, Held in Conjunction with the Materials Science and Technology 2012 Conference and Exhibition, MS and T 2012

AU - Rivera-Díaz-del-Castillo, P. E J

PY - 2012

Y1 - 2012

N2 - Recent work has demonstrated that bearing steels, which display ultra-hardness and -strength, possess a complex multiscalar microstructure responsible for their properties. This includes blocky retained austenite at the micron level, bainite subunits, and marteniste plates/laths at the submicron level, as well as a complex dispersion of precipitates in the range of tens of nanometres. The harmonious combination of those features leads both to excellent mechanical and rolling contact fatigue properties. This work reviews the microstructure-property relationships associated to those microstructures, and puts them in the context of a novel two-step bainitic treatment, which was demonstrated to display the highest hardness amongst a number of bainitically hardened steels studied. The phase transformations developed throughout the heat treatment of such steels is discussed, and an interpretation of the origin of their exceptional properties is provided.

AB - Recent work has demonstrated that bearing steels, which display ultra-hardness and -strength, possess a complex multiscalar microstructure responsible for their properties. This includes blocky retained austenite at the micron level, bainite subunits, and marteniste plates/laths at the submicron level, as well as a complex dispersion of precipitates in the range of tens of nanometres. The harmonious combination of those features leads both to excellent mechanical and rolling contact fatigue properties. This work reviews the microstructure-property relationships associated to those microstructures, and puts them in the context of a novel two-step bainitic treatment, which was demonstrated to display the highest hardness amongst a number of bainitically hardened steels studied. The phase transformations developed throughout the heat treatment of such steels is discussed, and an interpretation of the origin of their exceptional properties is provided.

KW - Bainite

KW - Nanostructured materials

KW - Two-step transformation

KW - Ultra-strong

M3 - Conference contribution/Paper

AN - SCOPUS:84869021149

SN - 9781935117278

SP - 295

EP - 302

BT - AIST Steel Properties and Applications Conference Proceedings - Combined with MS and T'12, Materials Science and Technology 2012

Y2 - 7 October 2012 through 11 October 2012

ER -