Micromechanics-based understanding of the stability of film-like austenite in steels

Abstract

Based on the carbon content and processing technique, the austenite morphology in steels can be either film-like or blocky. Experiments have shown that a film-like morphology of austenite shows a higher resistance to strain-induced martensitic transformation than its blocky counterpart. In the present work, using aspect ratio to distinguish austenite morphology, a micromechanical model is developed to show that the presence of an unfavourable stress field discourages the austenite to martensite transformation in film-like morphology, thereby lending its stable nature compared to the blocky version.

KEYWORDS:

• Strain-induced martensite transformation
• austenite morphology
• eigen strain
• hydrostatic stress
• shear stress

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Science and Engineering Research Board, Government of India. The principal author of this study (GK) was supported by the Prime Minister's Research Fellowship, Ministry of Human Resource Development (now Ministry of Education), Government of India.