Work

Investigation of microstructural evolution in nano-structured bainite during Paris law regime of fatigue crack growth

Year: 2025

Type: article

Abstract: Two different blocks of nano-bainitic specimens, NSB_250 and NSB_350 were prepared by austenitization at 950°C for 40 min, followed by austempering at 250°C and 350°C respectively. Lower austempering temperature led to thinner bainitic laths, smaller fraction of retained austenite (RA) and higher fatigue crack growth rates. This study investigated the microstructural evolution in both specimens close to the cracked surface when the crack growth was in the Paris law regime. Samples were extracted using focussed ion beam (FIB) milling and the microstructure was examined using transmission electron microscopy (TEM) and compared with that of undeformed specimens. Formation of deformation twins in RA were observed in NSB_350 while severe deformation of bainitic ferrite and micro-twin formation in RA was observed for NSB_250.

Source: Procedia Structural Integrity

DOI: 10.1016/j.prostr.2025.06.119

Authors: Bhawesh Chhajed, Sudharm Rathore, Avanish Kumar, Aparna Singh

Institutions: Indian Institute of Technology Bombay, Indian Institute of Technology Dhanbad

Language: English

Topic: Microstructure and Mechanical Properties of Steels

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: diamond

OpenAlex ID: W4412436501

FWCI: 0.297

Cites: 19

Cited by: 1

Related to: 10