Deakin University
Browse

File(s) under permanent embargo

A Novel Mo and Nb Microalloyed Medium Mn TRIP Steel with Maximal Ultimate Strength and Moderate Ductility

Version 2 2024-06-03, 10:58
Version 1 2015-03-10, 12:27
journal contribution
posted on 2024-06-03, 10:58 authored by M Cai, Z Li, Q Chao, Peter HodgsonPeter Hodgson
The multi-phase, metastable, and multi-scale (M3) constitution of a novel transformation-induced plasticity (TRIP) steel (Fe-0.17C-6.5Mn-1.1Al-0.22Mo-0.05Nb, wt pct) was designed through thermodynamic calculations combined with experimental analysis. In this study, Mo and Nb microalloying was used to control the fraction of retained austenite and its mechanical stability during tensile deformation and to improve the yield strength. Thermodynamic calculations were developed to determine the critical annealing temperature, at which a large fraction of retained austenite (~38 pct) would be obtained through the effects of solute enrichment. The experimental observation was in good agreement with the predicted results. According to the critical annealing temperature, such an ultrafine (<200 nm) M3, microstructure with optimum mechanical stability was successfully achieved. The results of this work demonstrated the superior performance with improved yield strength of 1020 to 1140 MPa and excellent ductility (>30 pct), as compared with other TRIP steels. Both angle-selective backscatter and electron backscatter diffraction techniques were employed to interpret the transformation from the deformed martensitic laths to the ultrafine austenite and ferrite duplex structure.

History

Journal

Metallurgical and materials transactions A: Physical metallurgy and materials science

Volume

45

Pagination

5624-5634

Location

New York, NY

ISSN

1073-5623

Language

eng

Publication classification

C Journal article, C1 Refereed article in a scholarly journal

Copyright notice

2014, Springer

Issue

12

Publisher

Springer