Next Article in Journal
Effects of Heating Mode and Temperature on the Microstructures, Electrical and Optical Properties of Molybdenum Thin Films
Previous Article in Journal
Mechanistic Insight into Etching Chemistry and HF-Assisted Etching of MgO-Al2O3-SiO2 Glass-Ceramic
Article Menu
Issue 9 (September) cover image

Export Article

Open AccessArticle
Materials 2018, 11(9), 1633; https://doi.org/10.3390/ma11091633

Effect of Reverse-phase Transformation Annealing Process on Microstructure and Mechanical Properties of Medium Manganese Steel

School of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot 010000, China
*
Author to whom correspondence should be addressed.
Received: 15 August 2018 / Revised: 30 August 2018 / Accepted: 3 September 2018 / Published: 6 September 2018
Full-Text   |   PDF [4266 KB, uploaded 6 September 2018]   |  

Abstract

In order to develop a third-generation automobile steel with powerful strength and elongation, we propose a method through high temperature quenching and two-phase region reverse-phase transformation annealing to develop such steel with 0.13% C and 5.4% Mn. To investigate the microstructure evolution and mechanical properties of manganese steel, SEM, XRD and TEM are employed in our experiments. Experimental results indicate that the microstructure after quenching is mainly lath martensite microstructure with average of lath width at 0.5 μm. The components of the steel after along with reverse-phase transformation annealing are ultra-fine grain ferrite, lath martensite and different forms of austenite microstructure. When the temperature at 625 °C, the components of the steel mainly includes lath martensite microstructure and ultra-fine grain ferrite and the fraction of austenite volume is only 5.09%. When the annealing temperature of reverse-phase transformation increase into 650 °C and 675 °C, the austenite appears in the boundary of the ferritic grain boundary and the boundary of lath martensite as the forms of bulk and lath. The phenomenon appears in the bulk of austenite, and the size of is 0.22 μm, 0.3 μm. The fraction of austenite volume is 22.34% at 675 °C and decreases into 9.32% at 700 °C. The components of austenite mainly includes ultra-fine grained ferrite and lath martensite. Furthermore, the density of decreases significantly, and the width of martensite increases into 0.32 μm. In such experimental settings, quenching at 930 °C with 20 min and at 675 °C with 30 min reverse-phase transformation annealing, the austenite volume fraction raises up to 22.34%. View Full-Text
Keywords: medium manganese steel; reverse transformation annealing; ultra-fine grained ferrite; austenite; strength-ductility combination medium manganese steel; reverse transformation annealing; ultra-fine grained ferrite; austenite; strength-ductility combination
Figures

Figure 1

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Zhao, Y.; Fan, L.; Lu, B. Effect of Reverse-phase Transformation Annealing Process on Microstructure and Mechanical Properties of Medium Manganese Steel. Materials 2018, 11, 1633.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Materials EISSN 1996-1944 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top