In situ studies of evolution of microstructure with temperature in heavily deformed Ti-modified austenitic stainless steel by X-ray Diffraction technique

TL;DR

This study investigates the early-stage microstructural evolution of heavily deformed Ti-modified austenitic stainless steel at high temperatures using X-ray diffraction, revealing mechanisms of domain growth and microstructure changes.

Contribution

It is the first to analyze the initial microstructural evolution during annealing of this steel using X-ray diffraction and TEM, proposing new mechanisms for early-stage microstructure development.

Findings

Significant changes in domain size with time and temperature.

Identification of two mechanisms involved in microstructural evolution.

Corroboration of X-ray diffraction results with TEM observations.

Abstract

The mechanism of the evolution of the deformed microstructure at the earliest stage of annealing where the existence of the lowest length scale substructure paves the way to the formation of the so-called subgrains, has been studied for the first time. The study has been performed at high temperature on heavily deformed Ti-modified austenitic stainless steel using X-ray diffraction technique. Significant changes were observed in the values of the domain size, both with time and temperature. Two different types of mechanism have been proposed to be involved during the microstructural evolution at the earliest stages of annealing. The nature of the growth of domains with time at different temperatures has been modelled using these mechanisms. High-resolution transmission electron microscopy has been used to view the microstructure of the deformed and annealed sample and the results have been corroborated successfully with those found from the X-ray diffraction techniques.