Influence of refined hierarchical martensitic microstructures on yield strength and impact toughness of ultra-high strength stainless steel

The hierarchical martensitic features in ultra-high strength stainless steel (UHSSS), including the prior austenite grains, martensite packets, blocks and laths with the descending size, were refined to various extents by employing different thermomechanical processes and then carefully characterize...

Full description

Saved in:
Bibliographic Details
Published inJournal of materials science & technology Vol. 51; pp. 130 - 136
Main Authors Luo, Haiwen, Wang, Xiaohui, Liu, Zhenbao, Yang, Zhiyong
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 15.08.2020
Subjects
Impact toughness
Martensite
retained austenite
Ultra-high strength stainless steel
Yield strength
Yield strength
Impact toughness
Ultra-high strength stainless steel
Martensite
retained austenite
Online AccessGet full text

Cover

More Information
Summary:The hierarchical martensitic features in ultra-high strength stainless steel (UHSSS), including the prior austenite grains, martensite packets, blocks and laths with the descending size, were refined to various extents by employing different thermomechanical processes and then carefully characterized. Their relation to yield strength and impact toughness was analyzed. We conclude that the refinement of martensitic structures could lead to the significant increase of yield strength, which follows the Hall-Petch relation with the effect grain size defined by high angle boundaries (HABs). Impact toughness of UHSSS depends on the frequency and capability for retained austenite (RA) grains at both HABs and martensite lath boundaries to trap the propagating cracks via strain-induced transformation, in which the film-like RA grains at lath boundaries appear to make the greater contribution.
ISSN:1005-0302
1941-1162
DOI:10.1016/j.jmst.2020.04.001